SD-13-4863
Bendix® EC-60™ ABS / ATC Controllers (Standard & Premium Models)
Frame and Cab Mount
Standard Frame |
Standard Cab |
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Premium Frame |
Premium Cab |
INTRODUCTION
Bendix® EC-60™ controllers are members of a family of electronic Antilock Braking System (ABS) devices designed to help improve the braking characteristics of air braked vehicles - including heavy and medium duty buses, trucks, and tractors. ABS controllers are also known as Electronic Control Units (ECUs).
Bendix ABS uses wheel speed sensors, ABS modulator valves, and an ECU to control either four or six wheels of a vehicle. By monitoring individual wheel turning motion during braking, and adjusting or pulsing the brake pressure at each wheel, the EC-60™ controller is able to optimize slip between the tire and the road surface. When excessive wheel slip, or wheel lock-up, is detected, the EC-60™ controller will activate the Pressure Modulator Valves to simulate a driver pumping the brakes. However, the EC-60™ controller is able to pump the brakes on individual wheels (or pairs of wheels), independently, and with greater speed and accuracy than a driver.
In addition to the ABS function, premium models of the EC-60™ controller provide an Automatic Traction Control (ATC) feature. Bendix ATC can improve vehicle traction during acceleration, and lateral stability while driving through curves. ATC utilizes Engine Torque Limiting (ETL) where the ECU communicates with the engine’s controller and/or Differential Braking (DB) where individual wheel brake applications are used to improve vehicle traction.
Premium EC-60™ controllers have a drag torque control feature which reduces driven-axle wheel slip (due to driveline inertia) by communicating with the engine’s controller and increasing the engine torque.
FIGURE 1 - EC-60™ CONTROLLERS
TABLE OF CONTENTS |
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General System Information |
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Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ECU Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 EC-60™ Controller Hardware Configurations . . . . 2 EC-60™ Controllers with PLC . . . . . . . . . . . . . . . . . 3 EC-60™ Controller Inputs . . . . . . . . . . . . . . . . . . . . 3 ABS Off-Road Switch and Indicator Lamp . . . . . . . 4 EC-60™ Controller Outputs . . . . . . . . . . . . . . . . . . . 4 Power-Up Sequence . . . . . . . . . . . . . . . . . . . . . . . . 5 ABS Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 ATC Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Dynamometer Test Mode . . . . . . . . . . . . . . . . . . . . 8 Automatic Tire Size Calibration . . . . . . . . . . . . . . . 8 ABS Partial Shutdown . . . . . . . . . . . . . . . . . . . . . . . 9
System Reconfiguration
EC-60™ Controller System Reconfiguration . . . . 10
Troubleshooting
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Diagnostic Trouble Codes . . . . . . . . . . . . . . . . . . 12 Using Hand-Held or PC-based Diagnostics . . . 13 Diagnostic Trouble Code Troubleshooting Index . 16 Trouble Code Tests . . . . . . . . . . . . . 18 - 27 Connector and Harnesses . . . . . . . . . . . . . . . 28-31 Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32-34 Wiring Schematics . . . . . . . . . . . . . . . . . . . . . 28-31 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
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Sensor
Clamping
90° Speed Sleeve
Sensors
Straight Speed
Sensors
FIGURE 2 - BENDIX® WS-24™ WHEEL SPEED SENSORS
Delivery
(Port 2)
Supply (Port 1)
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Electrical |
M-32™ |
M-32QR™ |
Connector |
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Modulator |
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Exhaust (Port 3) |
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FIGURE 3 - M-32™ AND M-32QR™ MODULATORS
FIGURE 4 - POWER LINE WITHOUT PLC SIGNAL
FIGURE 5 - POWER LINE WITH PLC SIGNAL
COMPONENTS
The EC-60™ controller’s ABS function utilizes the following components:
•Bendix® WS-24™ wheel speed sensors (4 or 6, depending on ECU model and configuration). Each sensor is installed with a Bendix Sensor Clamping Sleeve
•Bendix® M-32™ or M-32QR™ Pressure Modulator Valves (4, 5, or 6 depending on ECU model and configuration)
•Dash-mounted tractor ABS Indicator Lamp
•Service brake relay valve
•Dash-mounted trailer ABS Indicator Lamp (used on all towing vehicles manufactured after March 1, 2001)
•Optional blink code activation switch
•Optional ABS off-road switch. (Off-road feature is not available on all models - See Chart 1.)
The EC-60™ controller ATC function utilizes the following additional components:
•Traction control valve (may be integral to the service brake relay valve or a stand-alone device)
•Dash-mounted ATC status/indicator lamp
•J1939 serial communication to engine control module
•Stop lamp switch input (may be provided using the ECU hardware input or J1939)
•Optional ATC off-road switch
2
ECU MOUNTING
Cab ECUs
Cab-mounted EC-60™ controllers are not protected against moisture, and must be mounted in an environmentally protected area.
All wire harness connectors must be properly seated. The use of secondary locks is strongly recommended.
CAUTION: All unused ECU connectors must be covered and receive any necessary protection from moisture, etc.
Cab ECUs utilize connectors from the AMP MCP 2.8 product family.
Frame ECUs
Frame-mounted EC-60™ controllers may be mounted on the vehicle frame, but only in locations where they will not be subjected to direct tire spray. ECU mounting bolts must be torqued to 7.5 to 9 Nm.
CAUTION: The frame wire harness connectors must be properly seated with the seals intact (undamaged). All unused connector terminals must be plugged with the appropriate sealing plugs. Failure to properly seat or seal the connectors could result in moisture or corrosion damage to the connector terminals. ECUs damaged by moisture and/or corrosion are not covered under the Bendix warranty.
Frame ECUs utilize Deutsch connectors.
ECU |
Mounting |
Input |
Sensors |
PMVs |
ATC |
Blink |
Serial Communication |
PLC |
ABS |
ATC |
Retarder |
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Codes |
J1587 |
J1939 |
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Off-Road |
Off-Road |
Relay |
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Standard |
Cab |
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4 |
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Frame |
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Standard |
Cab |
12 |
4 |
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Frame |
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Premium |
Cab |
12 |
4/6 |
4/5/6 |
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Frame |
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Premium |
Cab |
24 |
4/6 |
4/5/6 |
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CHART 1 - EC-60™ CONTROLLERS AVAILABLE
HARDWARE CONFIGURATIONS
Standard Models
Standard model EC-60™ controllers support four sensor/ four modulator (4S/4M) applications. Certain models support Power Line Carrier (PLC) communications, with all models supporting 12 volt installations. See Chart 1 for more details.
Premium Models
Premium model EC-60™ controllers support applications up to six sensor/six modulator (6S/6M) installations with ATC and drag torque control. All 12 volt models support PLC. 24 volt models do not support PLC. See Chart 1 for more details.
EC-60™ CONTROLLERS WITH PLC
Since March 1, 2001, all towing vehicles must have an in-cab trailer ABS Indicator Lamp. Trailers transmit the status of the trailer ABS over the power line (the blue wire of the J560 connector) to the tractor using a Power Line Carrier (PLC) signal. See Figures 4 and 5. Typically the signal is broadcast by the trailer ABS ECU. The application of PLC technology for the heavy vehicle industry is known as “PLC4Trucks.” The Standard PLC EC-60™ controller and the Premium EC-60™ controller (12 volt versions) support PLC communications in accordance with SAE J2497.
Identifying an EC-60™ Controller with PLC
Refer to the information panel on the ECU label to see if the controller provides PLC.
An oscilloscope can be used to measure or identify the presence of a PLC signal on the power line. The PLC signal is an amplitude and frequency modulated signal. Depending on the filtering and load on the power line, the PLC signal amplitude can range from 5.0mVp-p to 7.0 Vp-p. Suggested oscilloscope settings are AC coupling, 1 volt/div, 100 µsec/ div. The signal should be measured at the ignition power input of the EC-60™ controller.
Note: An ABS trailer equipped with PLC, or a PLC diagnostic tool, must be connected to the vehicle in order to generate a PLC signal on the power line.
Alternatively, the part number shown on the ECU label can be identified as a PLC or non-PLC model by calling the Bendix TechTeam at 1-800-AIR-BRAKE (1-800-247-2725).
EC-60™ CONTROLLER INPUTS
Battery and Ignition Inputs
The ECU operates at a nominal supply voltage of 12 or 24 volts, depending on the model of the ECU. The battery input is connected through a 30 amp fuse directly to the battery.
The ignition input is applied by the ignition switch through a 5 amp fuse.
Ground Input
The EC-60™ controller supports one ground input. See pages 35 to 40 for system schematics.
ABS Indicator Lamp Ground Input (Cab ECUs
Only)
EC-60™ cab ECUs require a second ground input (X1-12) for the ABS indicator lamp. The X1 wire harness connector contains an ABS indicator lamp interlock (X1-15), which shorts the ABS indicator lamp circuit (X1-18) to ground if the connector is removed from the ECU.
Bendix® WS-24™ Wheel Speed Sensors
Wheel speed data is provided to the EC-60™ controller from the WS-24™ wheel speed sensor (see Figure 2). Vehicles have an exciter ring (or “tone ring”) as part of the wheel assembly, and as the wheel turns, the teeth of the exciter ring pass the wheel speed sensor, generating an AC signal. The EC-60™ controller receives the AC signal, which varies in voltage and frequency as the wheel speed changes.
Vehicle axle configurations and ATC features determine the number of WS-24™ wheel speed sensors that must be used. A vehicle with a single rear axle requires four wheel speed sensors. Vehicles with two rear axles can utilize six wheel speed sensors for optimal ABS and ATC performance.
3
Diagnostic Blink Code Switch
A momentary switch that grounds the ABS Indicator Lamp output is used to place the ECU into the diagnostic blink code mode and is typically located on the vehicle’s dash panel.
ABS Off-Road Switch and Indicator Lamp
Operation
WARNING: The ABS off-road mode should not be used on normal, paved road surfaces because vehicle stability and steerability may be affected. When the ECU is placed in the ABS off-road mode, the ABS Indicator Lamp will flash constantly to notify the vehicle operator that the off-road mode is active.
Premium EC-60™ controllers use a dash-mounted switch to place the ECU into the ABS off-road mode. In some cases, ECUs may also be put into the ABS off-road mode by one of the other vehicle control modules, using a J1939 message to the EC-60™ controller.
(If you need to know if your EC-60™ controller uses a J1939 message to operate the lamp, e-mail ABS@bendix.com, specifying the ECU part number, or call 1-800-AIR-BRAKE and speak to the Bendix TechTeam.)
Stop Lamp Switch (SLS)
The Premium EC-60™ controller monitors the vehicle stop lamp status. Certain vehicle functions, such as ATC and All-Wheel Drive (AWD), use the status of the stop lamp to know the driver’s intention. This can be provided to the ECU via J1939 communications, or hardware input.
EC-60™ CONTROLLER OUTPUTS
Bendix® M-32™ and M-32QR™ Pressure
Modulator Valves (PMV)
The Bendix® M-32™ and M-32QR™ pressure modulator valves (PMV) are operated by the EC-60™ controller to modify driver applied air pressure to the service brakes during ABS or ATC activation (See pages 6-8). The PMV is an electropneumatic control valve and is the last valve that air passes through on its way to the brake chamber. The modulator hold and release solenoids are activated to precisely modify the brake pressure during an antilock braking event. The hold solenoid is normally open and the release solenoid is normally closed.
Traction Control Valve (TCV)
Premium EC-60™ controllers will activate the TCV during differential braking ATC events. The TCV may be a separate valve or integrated into the rear axle relay valve.
4
ABS Indicator Lamp Control with Optional Diagnostic Blink Code Switch (Cab and Frame ECUs)
Cab and frame-mount EC-60™ controllers have internal circuitry to control the ABS Indicator Lamp on the dash panel.
The ABS Lamp Illuminates:
1.During power up (e.g. when the vehicle is started) and turns off after the self test is completed, providing no
Diagnostic Trouble Codes (DTCs) are present on the tractor.
2.If the ECU is unplugged or has no power.
3.When the ECU is placed into the ABS off-road mode (the lamp flashes rapidly).
4.To display blink codes for diagnostic purposes after the external diagnostic switch is activated.
Certain models of the EC-60™ controller communicate with other vehicle control modules to operate the ABS Indicator Lamp using serial communications. (If you need to know if your EC-60™ controller uses serial communications to operate the lamp, e-mail ABS@bendix.com, specifying the ECU part number, or call 1-800-AIR-BRAKE and speak to the Bendix TechTeam.)
Indicator Lamp Control Using Serial
Communications Links
As mentioned above, depending on the vehicle manufacturer, the dash indicator lamps (ABS, ATC, and trailer ABS) may be controlled using serial communications links. In these cases, the EC-60™ controller will send a serial communications message over the J1939 or J1587 links indicating the required status of the lamp(s). Another vehicle control module receives the message and controls the indicator lamp(s).
Retarder Relay Disable Output
The retarder relay disable output may be used to control a retarder disable relay.
When configured to use this output, the ECU will energize the retarder disable relay and inhibit the use of the retarder as needed.
SAE J1939 Serial Communications
A Controller Area Network (CAN) data link (SAE J1939) is provided for communication. This link is used for various functions, such as:
•To disable retarding devices during ABS operation
•To request torque converter lock-up during ABS operation
•To share information such as wheel speed and ECU status with other vehicle control modules
Premium EC-60™ controllers utilize the J1939 data link for ATC and drag torque control functions.
ABS System |
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Status Indicators |
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0.5 1.5 2.0 2.5 3.0 (sec.) |
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Powered Vehicle ABS |
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Indicator Light |
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Trailer ABS |
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Indicator Light |
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(PLC Detected)* |
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Trailer ABS |
ON |
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Indicator Light |
OFF |
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*Some vehicle manufacturers may illuminate the trailer ABS indicator lamp at power-up regardless of whether a
PLC signal is detected from the trailer or not. Consult the vehicle manufacturer’s documentation for more details.
FIGURE 6 - ABS DASH LIGHTS START UP SEQUENCE
Trailer ABS Indicator Lamp Control
Certain models of the EC-60™ controller activate a trailer ABS Indicator Lamp (located on the dash panel) that indicates the status of the trailer ABS unit on one, or more trailers, or dollies. Typically, the EC-60™ controller directly controls the trailer ABS Indicator Lamp based on the information it receives from the trailer ABS.
Alternatively, some vehicles require the EC-60™ controller to activate the trailer ABS Indicator Lamp by communicating with other vehicle controllers using serial communications. (If you need to know if your EC-60™ controller uses a serial communications message to operate the lamp, e-mail ABS@bendix.com, specifying the ECU part number, or call 1-800-AIR-BRAKE and speak to the Bendix TechTeam.)
SAE J1708/J1587 Serial Communications
An SAE J1708 data link, implemented according to SAE J1587 recommended practice, is available for diagnostic purposes, as well as ECU status messages.
ATC Lamp Output/ATC Off-Road Switch Input
Premium ECUs control the ATC dash lamp.
The ATC Lamp Illuminates:
1.During power up (e.g. when the vehicle is started) and turns off after the self test is completed, providing no diagnostic trouble codes are present.
2.When ATC is disabled for any reason.
3.During an ATC event (the lamp will flash rapidly).
4.When the ECU is placed in the ATC off-road mode (the lamp will flash slowly at a rate of 1.0 seconds on, 1.5 seconds off). This notifies the vehicle operator that the off-road mode is active.
ATC System |
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Power |
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Status Indicator |
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0.5 1.5 2.0 2.5 3.0 (sec.) |
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Engine torque limiting |
ON |
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and differential braking |
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No ATC |
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FIGURE 7 - ATC INDICATOR LIGHT START UP SEQUENCE
Interaxle Differential Lock Control (AWD Transfer Case)
Premium ECUs can control the interaxle differential lock (AWD transfer case). This is recommended on AWD vehicles, but the ECU must be specially configured to provide this feature. E-mail to ABS@bendix.com for more details.
POWER-UP SEQUENCE
WARNING: The vehicle operator should verify proper operation of all installed indicator lamps (ABS, ATC, and trailer ABS) when applying ignition power and during vehicle operation.
Lamps that do not illuminate as required when ignition power is applied, or remain illuminated after ignition power is applied, indicate the need for maintenance.
ABS Indicator Lamp Operation
The ECU will illuminate the ABS Indicator Lamp for approximately three seconds when ignition power is applied, after which the lamp will extinguish if no diagnostic trouble codes are detected.
The ECU will illuminate the ABS Indicator Lamp whenever full ABS operation is not available due to a diagnostic trouble code. In most cases, partial ABS is still available.
ATC Status/Indicator Lamp Operation
The ECU will illuminate the ATC lamp for approximately 2.5 seconds when ignition power is applied, after which the lamp will extinguish, if no diagnostic trouble codes are detected.
The ECU will illuminate the ATC Indicator Lamp whenever ATC is disabled due to a diagnostic trouble code.
Trailer ABS Indicator Lamp Operation
Certain models of the ECU will control the Trailer ABS Indicator Lamp when a PLC signal (SAE J2497) from a trailer ABS ECU is detected.
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FIGURE 8 - VEHICLE ORIENTATION (TYPICAL)
ECU Configuration Test
Within two seconds of the application of ignition power, the ECU will perform a test to detect system configuration with regards to the number of wheel speed sensors and PMVs. This can be audibly detected by a rapid cycling of the PMVs. (Note: The ECU will not perform the configuration test when wheel speed sensors show that the vehicle is in motion.)
Pressure Modulator Valve Chuff Test
After the performance of the configuration test, the EC-60™ controller will perform a Bendix-patented PMV Chuff Test. The Chuff Test is an electrical and pneumatic PMV test that can assist maintenance personnel in verifying proper PMV wiring and installation.
With brake pressure applied, a properly installed PMV will perform one sharp audible exhaust of air by activating the hold solenoid twice and the release solenoid once. If the PMV is wired incorrectly, it will produce two exhausts of air or none at all.
The EC-60™ controller will perform a PMV chuff test on all installed modulators in the following order:
•Steer Axle Right PMV
•Steer Axle Left PMV
•Drive Axle Right PMV
•Drive Axle Left PMV
•Additional Axle Right PMV
•Additional Axle Left PMV
The pattern will then repeat itself.
The ECU will not perform the PMV Chuff Test when wheel speed sensors show that the vehicle is in motion.
ABS OPERATION
Bendix ABS uses wheel speed sensors, ABS modulator valves, and an ECU to control either four or six wheels of a vehicle. By monitoring individual wheel turning motion during braking, and adjusting or pulsing the brake pressure at each wheel, the EC-60™ controller is able to optimize slip between the tire and the road surface. When excessive wheel slip, or wheel lock-up, is detected, the EC-60™ controller will activate the Pressure Modulator Valves to simulate a driver pumping the brakes. However, the EC-60™ controller is able to pump the brakes on individual wheels (or pairs of wheels), independently, and with greater speed and accuracy than a driver.
Steer Axle Control
Although both wheels of the steer axle have their own wheel speed sensor and pressure modulator valve, the EC-60™ controller blends the applied braking force between the two steering axle brakes. This Bendix patented brake application control, called Modified Individual Regulation (MIR), is designed to help reduce steering wheel pull during an ABS event on road surfaces with poor traction (or areas of poor traction, e.g. asphalt road surfaces with patches of ice).
Single Drive Axle Control (4x2 Vehicle)
For vehicles with a single rear drive axle (4x2), the brakes are operated independently by the EC-60™ controller, based on the individual wheel behavior.
Dual Drive Axle Control (4S/4M Configuration)
For vehicles with dual drive axles (6x4) using a 4S/4M configuration, one ABS modulator controls both right-side rear wheels and the other modulator controls both left-side rear wheels. Both wheels on each side receive equal brake pressure during an ABS stop. The rear wheel speed sensors must be installed on the axle with the lightest load.
Dual Rear Axle Control (6S/6M Configuration)
For vehicles with dual rear axles (6x4, 6x2) using a 6S/6M configuration, the rear wheels are controlled independently. Therefore, brake application pressure at each wheel is adjusted according to the individual wheel behavior on the road surface.
6x2 Vehicles with 6S/5M Configuration
6x2 vehicles can utilize a 6S/5M configuration, with the additional axle (a non-driven rear axle) having two sensors, but only one Pressure Modulator Valve. In this case, the PMV controls both wheels on the additional axle. The additional axle wheels would receive equal brake pressure, based on the wheel that is currently experiencing the most wheel slip.
6
Normal Braking
During normal braking, brake pressure is delivered through the ABS PMV and into the brake chamber. If the ECU does not detect excessive wheel slip, it will not activate ABS control, and the vehicle stops with normal braking.
Retarder Brake System Control
On surfaces with low traction, application of the retarder can lead to high levels of wheel slip at the drive axle wheels, which can adversely affect vehicle stability.
To avoid this, the EC-60™ controller switches off the retarder as soon as a lock-up is detected at one (or more) of the drive axle wheels.
When the ECU is placed in the ABS off-road mode, it will switch off the retarder only when ABS is active on a steer axle wheel and a drive axle wheel.
Optional ABS Off-Road Mode
On some road conditions, particularly when the driving surface is soft, the stopping distance with ABS may be longer than without ABS. This can occur when a locked wheel on soft ground plows up the road surface in front of the tire, changing the rolling friction value. Although vehicle stopping distance with a locked wheel may be shorter than corresponding stopping distance with ABS control, vehicle steerability and stability is reduced.
Premium EC-60™ controllers have an optional control mode that more effectively accommodates these soft road conditions to shorten stopping distance while maintaining optimal vehicle steerability and stability.
WARNING: The ABS off-road mode should not be used on normal, paved road surfaces because vehicle stability and steerability may be reduced. The flashing ABS Indicator Lamp communicates the status of this mode to the driver.
The vehicle manufacturer should provide the optional ABS off-road function only for vehicles that operate on unpaved surfaces or that are used in off-road applications, and is responsible for insuring that vehicles equipped with the ABS off-road function meet all FMVSS-121 requirements and have adequate operator indicators and instructions.
The vehicle operator activates the off-road function with a switch on the dash panel. A flashing ABS Indicator Lamp indicates to the driver that the ABS off-road function is engaged. To exit the ABS off-road mode, depress and release the switch.
All-Wheel Drive (AWD) Vehicles
AWD vehicles with an engaged interaxle differential (steer axle to rear axle)/AWD transfer case may have negative effects on ABS performance. Optimum ABS performance is achieved when the lockable differentials are disengaged, allowing individual wheel control.
Premium EC-60™ controllers can be programmed specifically for this configuration to control the differential
lock/unlock solenoid in the AWD transfer case. When programmed to do so, the ECU will disengage the locked interaxle/AWD transfer case during an ABS event and reengage it once the ABS event has ended.
ATC OPERATION
ATC Functional Overview
Just as ABS improves vehicle stability during braking, ATC improves vehicle stability and traction during vehicle acceleration. The EC-60™ controller ATC function uses the same wheel speed information and modulator control as the ABS function. The EC-60™ controller detects excessive drive wheel speed, compares the speed of the front, nondriven wheels, and reacts to help bring the wheel spin under control. The EC-60™ controller can be configured to use engine torque limiting and/or differential braking to control wheel spin. For optimal ATC performance, both methods are recommended.
ATC Lamp Operation
The ATC Lamp Illuminates:
1.During power up (e.g. when the vehicle is started) and turns off after the self test is completed, providing no diagnostic trouble codes are present.
2.When ATC is disabled for any reason.
3.During an ATC event (the lamp will flash rapidly). When ATC is no longer active, the ATC active/indicator lamp turns off.
4.When the ECU is placed in the ATC off-road mode (the lamp will flash at a rate of 1.0 seconds on, 1.5 seconds off). This notifies the vehicle operator that the off-road mode is active.
Differential Braking
Differential braking is automatically activated when drive wheel(s) on one side of the vehicle are spinning, which typically occur on asphalt road surfaces with patches of ice. The traction system will then lightly apply the brake to the drive wheel(s) that are spinning. The vehicle differential will then drive the wheels on the other side of the vehicle.
Differential braking is available at vehicle speeds up to 25 MPH.
Disabling ATC Differential Braking
ATC differential braking is disabled under the following conditions:
1.During power up (e.g. when the vehicle is started), until the ECU detects a service brake application.
2.If the ECU receives a J1939 message indicating that the vehicle is parked.
3.When the dynamometer test mode is active. The dynamometer test mode is entered using the diagnostic blink code switch or by using a diagnostic tool (such as Bendix® ACom™ Diagnostics).
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4.In response to a serial communications request from a diagnostic tool.
5.During brake torque limiting to avoid overheating of the brakes.
6.When certain diagnostic trouble code conditions are detected.
Engine Torque Limiting (ETL) with Smart ATC™ Traction Control
The EC-60™ controller uses Engine Torque Limiting to control drive axle wheel slip. This is communicated to the engine control module (using J1939), and is available at all vehicle speeds.
Bendix® Smart ATC™ Traction Control
The EC-60™ controller has an additional feature known as Smart ATC™ traction control. Smart ATC™ traction control monitors the accelerator pedal position (using J1939) to help provide optimum traction and vehicle stability. By knowing the driver’s intention and adapting the target slip of the drive wheels to the driving situation, the Smart ATC™ traction control allows higher wheel slip when the accelerator pedal is applied above a preset level.
The target wheel slip is decreased when driving through a curve for improved stability.
Disabling ATC Engine Control and Smart ATC™ Traction
Control
ATC Engine Control and Smart ATC™ traction control will be disabled under the following conditions:
1.In response to a serial communications request from an off-board tool.
2.At power-up until the ECU detects a service brake application.
3.If the ECU receives a J1939 message indicating that the vehicle is parked.
4.If the dynamometer test mode is active. This may be accomplished via an off-board tool or the diagnostic blink code switch.
5.When certain diagnostic trouble code conditions are detected.
Optional ATC Off-Road Mode
In some road conditions, the vehicle operator may desire additional drive wheel slip when ATC is active. The Premium EC-60™ controller has an optional control mode to permit this desired performance.
The vehicle operator can activate the off-road function with a switch on the dash panel. Alternately, a J1939 message may be used to place the vehicle in this mode. The ATC Indicator Lamp will flash continually to confirm that the offroad ATC function is engaged.
To exit the ATC off-road mode, depress and release the ATC off-road switch.
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Drag Torque Control Functional Overview
Premium EC-60™ controllers have a feature referred to as drag torque control which reduces wheel slip on a driven axle due to driveline inertia. This condition is addressed by increasing the engine torque to overcome the inertia.
Drag torque control increases vehicle stability on low-traction road surfaces during down-shifting or retarder braking.
Dynamometer Test Mode
WARNING: ATC must be disabled prior to conducting any dynamometer testing. When the Dynamometer Test Mode is enabled, ATC brake control and engine control along with drag torque control are turned off. This test mode is used to avoid torque reduction or torque increase and brake control activation when the vehicle is operated on a dynamometer for testing purpose.
The Dynamometer Test Mode may be activated by pressing and releasing the diagnostic blink code switch five times or by using a hand-held or PC-based diagnostic tool.
The Dynamometer Test Mode will remain active even if power to the ECU is removed and re-applied. Press and release the blink code switch three times, or use a hand-held or PC-based diagnostic tool to exit the test mode.
Automatic Tire Size Calibration
The ECU requires a precise rolling circumference ratio between steer axle and drive axle tires in order for ABS and ATC to perform in an optimal manner. For this reason, a learning process continuously takes place in which the precise ratio is calculated. This calculated value is stored in the ECU memory provided the following conditions are met:
1.Rolling-circumference ratio is within the permissible range.
2.Vehicle speed is greater than approximately 12 MPH.
3.No acceleration or deceleration is taking place.
4.There are no active speed sensor diagnostic trouble codes.
The ECU is provided with a ratio value of 1.00 as a default setting. If the automatic tire size alignment calculates a different value, this is used to overwrite the original figure in the memory. This process adapts the ABS and ATC function to the vehicle.
Acceptable Tire Sizes
The speed calculation for an exciter ring with 100 teeth is based on a default tire size of 510 revolutions per mile. This figure is based on the actual rolling circumference of the tires, which varies with tire size, tire wear, tire pressure, vehicle loading, etc.
The ABS response sensitivity is reduced when the actual rolling circumference is excessive on all wheels. For a 100 tooth exciter ring, the minimum number of tire revolutions
per mile is 426, and the maximum is 567. The ECU will set diagnostic trouble codes if the number or revolutions are out of this range.
In addition, the size of the steer axle tires compared to the drive axle tires also has to be within the ABS system design. To avoid diagnostic trouble codes, the ratio of the effective rolling circumference of the steer axle, divided by the effective rolling circumference of the drive axle, must be between 0.85 to 1.15.
ABS PARTIAL SHUTDOWN
Depending which component the trouble code is detected on, the ABS and ATC functions may be fully or partially disabled. Even with the ABS indicator lamp on, the EC60™ controller may still provide ABS function on wheels that are not affected. The EC-60™ controller should be serviced as soon as possible.
Steer Axle ABS Modulator Diagnostic Trouble
Code
ABS on the affected wheel is disabled. ABS and ATC on all other wheels remains active.
Drive Axle/Additional Axle ABS Modulator
Diagnostic Trouble Code
ATC is disabled. ABS on the affected wheel is disabled. ABS on all other wheels remains active.
Steer Axle Wheel Speed Sensor Diagnostic
Trouble Code
The wheel with the diagnostic trouble code is still controlled by using input from the remaining wheel speed sensor on the front axle. ABS remains active on the rear wheels. ATC is disabled.
Drive Axle/Additional Axle Wheel Speed Sensor
Diagnostic Trouble Code
ATC is disabled. In a four sensor system, ABS on the affected wheel is disabled, but ABS on all other wheels remains active.
In a six sensor system, ABS remains active by using input from the remaining rear wheel speed sensor on the same side.
ATC Modulator Diagnostic Trouble Code
ATC is disabled. ABS remains active.
J1939 Communication Diagnostic Trouble Code
ATC is disabled. ABS remains active.
ECU Diagnostic Trouble Code
ABS and ATC are disabled. The system reverts to normal braking.
Voltage Diagnostic Trouble Code
While voltage is out of range, ABS and ATC are disabled. The system reverts to normal braking. When the correct voltage level is restored, full ABS and ATC function is available. Operating voltage range is 9.0 to 17.0 VDC.
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Reconfiguring EC-60™ Controllers
SYSTEM CONFIGURATION
The EC-60™ controller is designed to allow the technician to change the default system settings (chosen by the vehicle OEM) to provide additional or customized features. When replacing an ECU, be sure to use an equivalent Bendix replacement part number so that the standard default settings are provided.
Depending on the model, the customizable features include ABS control settings, engine module communication etc. Many of these settings can be reconfigured using a handheld or PC-based software, such as the Bendix® ACom™ Diagnostics program.
ECU RECONFIGURATION
Reconfiguring Standard ECUs
Reconfigurating an EC-60™ controller may be carried out by using the Blink Code Switch or by using a hand-held or PC-based diagnostic tool.
Note: During the reconfiguration process, and independently from any reconfiguration being carried out by the technician, standard ECUs automatically check the J1939 serial link and communicate with other vehicle modules. In particular, if the serial link shows that the vehicle has a retarder device present, the ECU will configure itself to communicate with the retarder device for improved ABS performance. For example, if the ECU detects the presence of a retarder disable relay during a reconfiguration, it will configure itself to control the relay to disable the retarding device as needed.
Reconfiguring Premium ECUs
As with standard ECUs, the Premium EC-60™ controller also carries out, independently from any reconfiguration being carried out by the technician, an automatic check of the J1939 serial link and communicate with other vehicle modules. This includes checking for ATC and retarder disable relay operation. In addition, premium EC-60™ controllers will determine the number of wheel speed sensors and PMVs installed and configure itself accordingly.
6S/5M Configuration
Premium EC-60™ controllers will configure for 6S/5M operation when a reconfiguration event is initiated and the ECU detects that an additional axle PMV is wired as follows:
PMV Connector |
ECU Connector |
Hold |
Right Additional Axle Hold |
Release |
Left Additional Axle Release |
Common |
Right Additional Axle Common |
See 6S/5M System Schematics (pages 37 & 40) for details.
Reconfiguration Using the Blink Code Switch
The reconfiguration event is the same for both Standard and Premium ECUs. With ignition power removed from the EC-60™ controller, depress the blink code switch. After the ignition power is activated, depress and release the switch seven times to initiate a reconfiguration event.
Diagnostic Tool
A reconfiguration event may be initiated using a hand-held or PC-based diagnostic tool to communicate with the ECU over the SAE J1587 diagnostic link.
10
Troubleshooting: General
SAFE MAINTENANCE PRACTICES
WARNING! PLEASE READ AND FOLLOW THESE INSTRUCTIONS TO AVOID PERSONAL INJURY OR DEATH:
When working on or around a vehicle, the following general precautions should be observed at all times:
10.Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.
11.For vehicles with Antilock Traction Control (ATC), the ATC function must be disabled (ATC indicator lamp should be ON) prior to performing any vehicle maintenance where one or more wheels on a drive axle are lifted off the ground and moving.
1.Park the vehicle on a level surface, apply the
parking brakes, and always block the wheels. REMOVING THE EC-60™ CONTROLLER
Always wear safety glasses.
2.Stop the engine and remove ignition key when working under or around the vehicle. When working in the engine compartment, the engine should be shut off and the ignition key should be removed. Where circumstances require that the engine be in operation, EXTREME CAUTION should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated or electrically charged components.
3.Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures. Use only the proper tools and observe all precautions pertaining to use of those tools.
4.If the work is being performed on the vehicle’s air brake system, or any auxiliary pressurized air systems, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle. If the vehicle is equipped with an AD-IS® air dryer system or a dryer reservoir module, be sure to drain the purge reservoir.
5.Following the vehicle manufacturer’s recommended procedures, deactivate the electrical system in a manner that safely removes all electrical power from the vehicle.
6.Never exceed manufacturer’s recommended pressures.
7.Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.
8.Use only genuine Bendix® replacement parts, components and kits. Replacement hardware, tubing, hose, fittings, etc. must be of equivalent size, type and strength as original equipment and be designed specifically for such applications and systems.
9.Components with stripped threads or damaged parts should be replaced rather than repaired. Do not attempt repairs requiring machining or welding unless specifically stated and approved by the vehicle and component manufacturer.
ASSEMBLY
1.Turn vehicle ignition off.
2.Remove as much contamination as possible prior to disconnecting air lines and electrical connections.
3.Note the EC-60™ controller assembly mounting position on the vehicle.
4.Disconnect the electrical connectors from the EC-60™ controller.
5.Remove and retain the mounting bolts that secure the EC-60™ controller.
INSTALLING A NEW EC-60™ CONTROLLER
CAUTION! When replacing the EC-60™ controller, verify that the unit you are installing has the correct default settings. Failure to do so could result in a loss of features, such as ATC and PLC, or noncompliance with U.S. regulations such as FMVSS 121. It is recommended to use only the correct replacement part number. However, most configuration settings can be altered using the Bendix ACom™ ABS Diagnostic Software program.
Verify correct operation of the EC-60™ controller system and indicator lamps prior to putting the vehicle back into service. Towing vehicles manufactured after March 1, 2001 must support the trailer ABS indicator lamp located on the dash.
For further information, contact either the vehicle manufacturer, Bendix or your local authorized Bendix dealer.
1.Position and secure the EC-60™ controller in the original mounting orientation using the mounting bolts retained during removal. On frame-mount ECUs, torque the mounting bolts to 7.5 to 9 NM (66-80 in. Ibs). For cabmount units use no more torque than is necessary to firmly secure the ECU into position. Over-tightening the mounting hardware can cause damage to the EC-60™ controller.
2.Reconnect the electrical connectors to the EC-60™ controller.
3.Apply power and monitor the EC-60™ controller powerup sequence to verify proper system operation.
See Troubleshooting: Wiring section beginning on page 32 for more information on wire harnesses.
11
Troubleshooting: Blink Codes and Diagnostic Modes
ECU DIAGNOSTICS
The EC-60™ controller contains self-testing diagnostic circuitry that continuously checks for the normal operation of internal components and circuitry, as well as external ABS components and wiring.
Active Diagnostic Trouble Codes
When an erroneous system condition is detected, the EC-60™ controller:
1.Illuminates the appropriate indicator lamp(s) and disengages part or all of the ABS and ATC functions. (See page 9.)
2.Places the appropriate trouble code information in the ECU memory.
3.Communicates the appropriate trouble code information over the serial communications diagnostic link as required. Hand-held or PC-based diagnostic tools attach to the vehicle diagnostic connector, typically located on or under the dash (see Figure 9).
Located on |
Or |
Located Under |
|
Dash Panel |
Dash Panel |
||
|
FIGURE 9 - TYPICAL VEHICLE DIAGNOSTIC CONNECTOR LOCATIONS (J1708/J1587, J1939)
BLINK CODES
Blink codes allow a technician to troubleshoot ABS problems without using a hand-held or PC-based diagnostic tool. Instead, information about the ABS system is communicated by the ECU using the ABS indicator lamp to display sequences of blinks.
Note: The ECU will not enter the diagnostic blink code mode if the wheel speed sensors show that the vehicle is in motion. If the ECU is in the diagnostic blink code mode and then detects vehicle motion, it will exit the blink code mode.
In addition, by operating the blink code switch as described below, one of several diagnostic modes can be entered. See Diagnostic Modes below.
Blink Code Switch Activation
When activating the blink code switch:
1.Wait at least two seconds after “ignition on.” (Except when entering Reconfiguration Mode - see Reconfiguration section on page 10)
2.For the ECU to recognize that the switch is activated “on,” the technician must press for at least 0.1 seconds, but less than 5 seconds. (If the switch is held for more than 5 seconds, the ECU will register a malfunctioning switch.)
3.Pauses between pressing the switch when a sequence is required, (e.g. when changing mode) must not be longer than 2 seconds.
4.After a pause of 3.5 seconds, the ECU will begin responding with output information blinks. See Figure 10 for an example.
Blink Code Timing
The ECU responds with a sequence of blink codes. The overall blink code response from the ECU is called a “message.” Each message includes, depending on the
FIGURE 10 - EXAMPLE OF BLINK CODE MESSAGE
12
mode selected by the technician, a sequence of one or more groups of blinks. Simply record the number of blinks for each sequence and then use the troubleshooting index on page 17 for active or inactive trouble codes and you will be directed to the page that provides troubleshooting information.
NOTE:
1.Sequences of blinks illuminate the ABS indicator lamp for half a second, with half-second pauses between them.
2.Pauses between blink code digits are 1.5 seconds.
3.Pauses between blink code messages are 2.5 seconds.
4.The lamp remains on for 5 seconds at the end of messages.
Once the ABS indicator lamp begins displaying a sequence of codes, it continues until all blink code messages have been displayed and then returns to the normal operating mode. During this time, the ECU will ignore any additional blink code switch activation.
All trouble codes, with the exception of voltage and J1939 trouble codes, will remain in an active state for the remainder of the power cycle.
Voltage trouble codes will clear automatically when the voltage returns within the required limits. All ABS functions will be re-engaged.
J1939 trouble codes will clear automatically when communications are re-established.
DIAGNOSTIC MODES
In order to communicate with the ECU, the controller has several modes that the technician can select, allowing information to be retrieved, or other ECU functions to be accessed.
Diagnostic Modes
To enter the various diagnostic modes:
No. of Times to
Press the Blink System Mode Entered
Code Switch
1Active diagnostic trouble code retrieval
2Inactive diagnostic trouble code retrieval
3Clear active diagnostic trouble codes
4System configuration check
5Dynamometer Test Mode
7* Reconfigure ECU
* To enter the Reconfiguration Mode, the switch must be held in before the application of ignition power. Once the power is supplied, the switch is released and then pressed seven times.
CHART 2 - DIAGNOSTIC MODES
Active Diagnostic Trouble Code Mode
For troubleshooting, typically the Active and Inactive Diagnostic Trouble Retrieval Modes are used. The technician presses the blink code switch once and the ABS indicator lamp flashes a first group of two codes, and if there are more trouble codes recorded, this is followed by a second set of codes, etc. (See page 17 for a directory of these codes.) All active trouble codes may also be retrieved using a hand-held or PC-based diagnostic tool, such as the Bendix® ACom™ Diagnostics software.
To clear active diagnostic trouble codes (as problems are fixed), simply clear (or “self-heal”) by removing and re-applying ignition power. The only exception is for wheel speed sensor trouble codes, which clear when power is removed, re-applied, and the ECU detects valid wheel speed from all wheel speed sensors. Alternately, codes may be cleared by pressing the diagnostic blink code switch 3 times (to enter the Clear Active Diagnostic Trouble Code Mode) or by using a hand-held or PC-based diagnostic tool. Handheld or PC-based diagnostic tools are able to clear wheel speed sensor trouble codes without the vehicle being driven.
Inactive Diagnostic Trouble Code Mode
The ECU stores past trouble codes and comments (such as configuration changes) in its memory. This record is commonly referred to as “event history.” When an active trouble code is cleared, the ECU stores it in the event history memory as an inactive trouble code.
13
Using blink codes, the technician may review all inactive trouble codes stored on the ECU. The ABS indicator lamp will display inactive diagnostic blink codes when the diagnostic blink code switch is depressed and released two times. See page 17 for the index showing trouble codes and the troubleshooting guide page to read for help.
Inactive trouble codes, and event history, may be retrieved and cleared by using a hand-held or PC-based diagnostic tool, such as the Bendix® ACom™ Diagnostics software.
Clearing Active Diagnostic Trouble Codes
The ECU will clear active trouble codes when the diagnostic blink code switch is depressed and released three times.
System Configuration Check Mode
The ABS indicator lamp will display system configuration information when the diagnostic blink code switch is depressed and released four times. The lamp will blink out configuration information codes using the following patterns. (See Chart 3). In this mode the ECU tells the technician, by means of a series of six blink codes, the type of ABS system that the ECU has been set up to expect. For example, if the fourth blink code is a three, the technician knows that a 6S/5M sensor/modulator configuration has been set.
Dynamometer Test Mode
The Dynamometer Test Mode is used to disable ATC when needed (e.g. when performing any vehicle maintenance where the wheels are lifted off the ground and moving, including dyno testing). This mode is not reset by power off, power on, cycling. Instead a hand-held or PC-based diagnostic tool must be used to change the setting. Alternatively, depressing and releasing the blink code switch three times will cause the ECU to exit the blink code mode.
Reconfigure ECU Mode
Vehicle reconfiguration is carried out by using the Reconfigure ECU Mode. (See page 10.) Note: To enter the Reconfiguration Mode, the blink code switch must be held in before the application of ignition power. Once the power is supplied, the switch is released and then pressed seven times.
14
1st Number |
System Power |
|
1 |
12 Volts |
|
2 |
24 Volts |
|
|
|
|
2nd Number |
Wheel Speed Sensors |
|
4 |
4 |
Sensors |
6 |
6 |
Sensors |
|
|
|
3rd Number |
Pressure Modulator Valves |
|
4 |
4 |
Modulators |
5 |
5 |
Modulators |
6 |
6 |
Modulators |
|
|
|
4th Number |
ABS Configuration |
|
1 |
4S/4M or 6S/6M |
|
2 |
6S/4M |
|
3 |
6S/5M |
|
|
|
|
5th Number |
Traction Control Configuration |
|
2 |
No ATC |
|
3 |
ATC Engine Control Only |
|
4 |
ATC Brake Control Only |
|
5 |
Full ATC (Engine Control & Brake Control) |
|
|
|
|
6th Number |
Retarder Configuration |
|
1 |
No Retarder |
|
2 |
J1939 Retarder |
|
3 |
Retarder Relay |
|
4 |
J1939 Retarder, Retarder Relay |
|
|
|
|
CHART 3 - SYSTEM CONFIGURATION CHECK
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