BENDIX BW2187 User Manual

TROUBLESHOOTING THE BENDIX MC-30 TRAILER ANTILOCK SYSTEM

ABS Warning

Lamp

Pigtail 30-Pin

onnector

C

F

G

K J H

E1 +12V Ignition Power
E3 +12V Brake Light Power
D2 Ground
D1 N/A

D3 ABS Warning Lamp (Source)

C2 Right Front Wheel Speed +
A1 Right Front Wheel Speed -

A2 Left Front Wheel Speed +
A3 Left Front Wheel Speed -

B1 Right Rear Wheel Speed +
B2 Right Rear Wheel Speed -

B3 Left Rear Wheel Speed +
C1 Left Rear Wheel Speed -

J2 Modulator 1 Hold
H3 Modulator 1 Common
J3 Modulator 1 Exhaust

H2 Modulator 2 Hold
J1 Modulator 2 Common
K1 Modulator 2 Exhaust

G1 Diagnostic, J1587, Serial A
G2 Diagnostic, J1587, Serial B
E2 Diagnostic, +12v Ignition
C3 Diagnostic, GND

K3 Auxiliary Switch Input #1
F2 Auxiliary Switch Input #2
G3 Auxiliary Switch Input #3
H1 Auxiliary Switch Input #4
F3 Auxiliary Switch Input #5

F1 Auxiliary Low Side Output
K2 Auxiliary High Side Output

Electrical Connector

Ignition

Power

E

7-Pin Trailer

Ground

Brake Light

Power

B A

D

C

POWER-UP SEQUENCE
WARNING LAMP SEQUENCE: When power is applied, the trailer
ABS Warning Lamp will turn on for a 2.5 second bulb check, and
then turn off. If a PLC tractor and PLC trailer are powered at the
same time, the MC-30 will also trigger a 2.5 second bulb check
on the tractor dash using PLC.
CHUFF TEST: The MC-30 will perform a modulator “chuff test”
at power-up. With brake pressure applied, a properly installed
modulator will cause five rapid, audible chuffs of air pressure. If
two modulators are installed, the MC-30 activates five chuffs at
MOD1 and then MOD2. The chuff sequence is then repeated.
LED SEQUENCE: At power up, the diagnostic LEDs all turn on,

MC-30

P.N. 560560-2

ABS

If light remains on,

ABS unit should be serviced.

1-800-AIR-BRAKE

30-PIN

CONNECTOR

then display the current configuration.

Tie Wrap

At power-up All LEDs

1st blink displays number of wheel speed sensors

Wheel Speed

Sensor

TYPICAL

TRAILER AXLE

Mounting

Block

DIAGNOSTIC DISPLAY

2 Sensors SEN-FRT

4 Sensors SEN-RER-FRT

2nd blink displays modulator configuration

1 Modulator (Dolly-Axle control) MOD

1 Modulator (Axle control) MOD-FRT

2 Modulators (Axle control) MOD-RER-FRT

2 Modulators (Side control) MOD-LFT-RHT

Normal Operation

No Faults VLT (green) LED illuminated only

Bendix
iagnostic

D

1
2
3

round

G

Ignition

er

ow

P

Tools

itch

Aux Sw

Input #1

itch

w

Aux S

Input #2

itch

Aux Sw

Input #3

itch

Aux Sw

Input #4

itch

Aux Sw

Input #5

igh Side

Aux H

utput Load

O

Side

Aux Low

utput Load

O

D

C

A

E

B

D

C

A

E

B

E2

3

C

2

1, G

G

K3

F2

3

G

1

H

F3

K2

F1

2

D

3

D

3

E

5-Pin ABS

Connector

A Brake Light Power
B Ignition Power
C N/A
D Trailer ABS Warning Lamp
E Ground

ABS Warning Light

t

ron

t F

igh

R

S-20

W

2

C

A1

3

H

J3

D

O

M

-30

C

M

J2

1

RESET

r

a

e

t R

h

ig

R

S-20

W

B2

B1

3-PIN MOD1

CONNECTOR

CAUTION: An incorrect ABS configuration may
cause a fault indication or degraded
ABS performance. All MC-30 service
replacement parts are initially defaulted to
4S/2M side control and may need to be
reconfigured upon installation. Before and
after activating a self-configuration, always
determine the current ABS configuration by

-30T

M

J1

2K1

H

2

D

O

1

E

A2

A3

S-20

W

ro

ft F

Le

round

G

M

1

C

B3

S-20

W

isted

t

n

Tw

onductor

C

Brake Lines

r

ea

ft R

e

L

monitoring the diagnostic LEDs at power-up
or by activating blink code diagnostics.

ABS

Configuration

Control Group A Control Group B

2S/1M Axle Dolly-Axle

2S/2M Axle Side

4S/2M Axle Side

Toggle

Toggle

Toggle

FAULT DETECTION: When a fault is detected, the trailer ABS warn­ing lamp will remain on. If the tractor and trailer are equipped
with PLC, the dash mounted trailer ABS lamp will also remain
on. The warning lamps notify the driver that all or part of the ABS
function has been disengaged and standard air braking is in ef­fect. The faulted component will be identified on the diagnostic
display.
FAULT RESET: The MC-30 will automatically reset (self-heal) the
active fault code when the fault is corrected. Repeated occur­rences of a given fault will cause the fault code to latch. Once the
fault code is latched, the fault code will need to be cleared by a
magnetic reset or through blink code diagnostics.
MAGNETIC RESET: The ECU can be reset by momentarily hold­ing a magnet against the RESET area on the controller. All the
LEDs will be on while the magnet is held in place. If faults occur
on multiple components, the LEDs will display one fault at a time.
When the first fault is cleared and the MC-30 is reset, the next
fault will be displayed on the LEDs.
SELF-CONFIGURATION: This is generally performed after replace­ment of an MC-30. When activated with a magnet or diagnostic
tool, the wheel speed sensor, modulator and ABS control set­tings can be altered. After holding a magnet on the ECU reset
location for 20 seconds, the LEDs will begin to roll and the MC­30 will self-configure. IF IT IS NOT DESIRED TO TOGGLE THE
ABS CONTROL, REMOVE THE MAGNET AFTER 20 SECONDS.
ABS CONTROL TOGGLE: The MC-30 ABS control setting can be
toggled between axle control, dolly-axle control or side control.
To activate an ABS control toggle, continue to hold the magnet in
place while the LEDs are rolling, for an additional 20 seconds (a
total of 40 seconds). The LEDs will begin to flash rapidly. Re­move the magnet. Verify the new ABS configuration by monitor­ing the LED sequence at power-up or by activation of blink code
diagnostics.

MC-30 — LED Power-Up Sequence

BLINK CODE DIAGNOSTICS
The MC-30 provides diagnostic and configuration information through blink code
diagnostics. Blink code diagnostics are activated by providing constant power to the ignition
circuit and toggling the brake light power input to the MC-30.

When blink code mode is activated, the MC-30 will blink the trailer mounted ABS warning lamp
to display active fault codes, fault code history, ABS configurations, and odometer

DIAGNOSTIC LED REFERENCE
If the LEDs shown below are illuminated...

Sensor Fault
The example shown is a Right Front Sensor fault.

mileage. Blink code diagnostics can also be used to reset active fault codes.

With Ignition Power Applied,

Cycle Brake Light Power

3 times Display Active Fault Codes
4 times Display Fault Code History
5 times Reset Active Fault Codes
6 times Display EC-30T Configuration

7 times (If Equipped) Display of Odometer Mileage (x1000)

• If wheel speeds are detected during blink code diagnostics mode, the MC-30 will exit
blink code diagnostics and return to normal operating mode.

• Blink code diagnostics can only be activated following a power-up, where wheel speeds
have not been detected.

• Blink code diagnostics must be activated within 15 seconds of ignition power being ap­plied.

• If brake light power is continuously applied for greater than 5 seconds, blink code diag­nostics will be disabled until ignition power is cycled.

Lamp Behavior During Blink Code Display
Following activation, there will be a 5 second delay followed by the blink code display.
Following a single display of all available messages, the ABS warning lamp will remain on for 5
seconds and then return to normal operating mode.

CALIBRATION OF NON-STANDARD WHEEL SIZES
The MC-30 allows for tire rolling radius and tone ring tooth count parameters to be set for each
axle using a diagnostic tool. These adjustments may be necessary for the MC-30 to accurately
calculate the vehicle velocity and odometer mileage. Wheels of the same axle must be set to the
same rolling radius and tone ring tooth count. In most cases, these parameters are set by the
trailer OEM and do not need to be adjusted. In the case of a service replacement unit, these
parameters will need to be adjusted if the default settings do not match the vehicle.

Parameter Default Settings Available Settings

Rolling 500 revs/mile 300 to 700 revs/mile
Radius

Tone Ring 100 teeth

Tooth Count

WHEEL SPEED SENSOR ADJUSTMENT
Speed sensors are properly adjusted by gently pushing (not striking) the sensor into the clip
until it makes contact with the face of the tone ring. The wheel speed sensor will automatically
adjust as the wheel rotates. If rotating the wheel causes a gap of 0.020 in. or greater, check for
excessive wheel bearing play or tone ring run-out. Proper wheel speed sensor installation is

Blink Code Action

80, 86, 100, 120 teeth

Static Wheel Speed Sensor Fault
Verify 1500-2500 OHMs across sensor
connector pins
Dynamic Wheel Speed Sensor Fault
Rotate wheel and verify a minimum of 0.8VAC
sensor output @1RPS across wheel speed sen­sor pins. A properly positioned sensor can
output more than 2.0VAC @1RPS.

Modulator Fault
The example shown is a MOD1 fault.

Static ABS Modulator Fault
* Verify 7.0 to 10.0 OHMs across Hold and
Common Pins
* Verify 7.0 to 10.0 OHMs across Exhaust and
Common Pins
* Verify 14.0 to 20.0 OHMs across Exhaust and
Hold pins

ECU Fault
The example shown is an ECU fault. The red ECU
LED indicates a fault internal to the EC-30T. Reset
the MC-30 with a magnet. If the fault returns,
replace the EC-30T. If the red ECU LED is on and
the green VLT LED is off, the MC-30 may have very
low voltage.

Voltage Out of Range Fault
A flashing green VLT LED indicates ECU voltage below 8.0 VDC or above 16.0 VDC. The VLT
LED will blink until power is brought into normal range.

DIAGNOSTIC TOOLS
The MC-30 uses the Bendix ABS Diagnostic Software (PN 5009089) for advanced trouble­shooting on PC’s. The Bendix ABS Diagnostic Software requires an RP1210A* adapter. These adapt­ers are available from MPSI (Serial data module - PN 129037* and Parallel data module - PN 126032*).
Additional diagnostic tools are available through SPX. A Bendix PCMCIA card is available for the Pro­Link tool. It can be used with EC-15, EC-16, EC-17, EC-30 tractor ABS units and MC-30 trailer ABS
units.

critical to proper ABS operation.

PLC4Tr ucks
An MC-30 with PLC will continuously broadcast
PLC messages that indicate trailer ABS status.
At power-up or during a trailer fault condition, the
MC-30 will signal the tractor ABS unit to illumi­nate the dash mounted trailer ABS lamp. An os­cilloscope can be used to verify the presence and
strength of a PLC signal on the power line. Sug­gested oscilloscope settings are AC coupling, 1
volt/div, 100 sec/div. Diagnostic tools are avail­able that detect the presence of a PLC signal.

Power Line with PLC

*NEXIQ part nos. Order from your NEXIQ supplier.

Pro-Link

Heavy Duty

Multi Protocol

Cartridge

BW2187 © 2003 Bendix Commercial Vehicle Systems LLC 6/2003 Printed in U.S.A. All rights reserved.

30-Pin Connector

1
2
3

KJHGF EDCBA

C2 Right Front WS+
A1 Right Front WS­A2 Left Front WS+
A3 Left Front WS­B1 Right Rear WS+
B2 Right Rear WS-

B3 Left Rear WS+
C1 Left Rear WS-

E1 Ignition Power
E3 Brake Light Power
D2 Ground

30-Pin Connector

1
2
3

KJHGF EDCBA

J2 Mod1 Hold
H3 Mod1 Common
J3 Mod1 Exhaust
H2 Mod2 Hold
J1 Mod2 Common

E1 Ignition Power
E3 Brake Light Power
D2 Ground

K1 Mod2 Exhaust

PC Card MPSI

Part Number

801013*

For Additional Information:
Refer to SD-13-4834
Call 1-800-AIR-BRAKE (1-800-247-2725)
Visit: www.Bendix.com

POWER AND GROUND
Trailer electrical power is supplied to the MC-30 from the ignition and
brake light circuits.

Circuit 7-Pin Trailer 5-Pin ABS 30-Pin ECU

Ignition Power (PLC) Pin 7 B Pin E1

(Blue Wire)

Brake Light Power Pin 4 A Pin E3

(Red Wire)

Ground Pin 1 E Pin D2

(White Wire)

Warning Lamp N/A D Pin D3

(White/Green Wire)

Function Mode Value

Operating Range 8.0 to 16.0 VDC

ECU Active 383 mA
ABS Active 2.4 A @ 12 VDC

(1 modulator)

ABS Active 4.5 A @ 12 VDC

(2 modulators)

Electrical Power Connector

Connector Connector

MC-30 WIRING HARNESS (PIGTAIL)
The EC-30T utilizes a pigtail wiring harness to interface with ABS and
other trailer system components. The following connectors are optional
and may not be present on all pigtail harnesses: Modulator 2, auxiliary,
diagnostic, and rear axle wheel speed sensors.

ECU Connector Jackscrew

(Tighten to 15-20 in. lbs.)

3-Pin

Modulator 2

(MOD2)

8-Pin

Auxiliary

(AUX)

3-Pin

Modulator 1

(MOD 1)

5-Pin Power and

Warning Lamp

(PWR/WL)

MOST COMMONLY ENCOUNTERED PROBLEMS THAT RESULT IN LEDS
BEING ILLUMINATED

1. Abraded or cut wires in the convoluted tubing near frame clamps.

2. Damaged wires near frame members and frame mounted modulators.

3. Wire jacket worn through from overlapping sensor and modulator wires near frame
members and frame mounted modulators.

4. Corroded connectors or seal damage.

5. Damaged connector latches or connectors not completely seated.

6. Terminals not completely latched or sea ted into connectors.

7. Excessive sensor air gap, sensor clip tension, or excessive bearing end play (gently
push sensor against wheel hub, or readjust bearings).

8. Damage to exposed wires exiting or entering the convoluted tubing.

9. Worn, chipped or damaged sensor or modulator.

10. Non-functioning antilock controller.

ADDITIONAL SERVICING TIPS

1. Do not pierce wires with probes when troubleshooting harnesses.

2. Gently probe terminals when checking for resistances,
tacts.

3. Apply nonconductive dielectric grease to any and all connectors if inspect­ing or disconnecting connectors.

4. Bundle and tie wrap excess cable neatly to adjacent air lines or framing
members.

4-Pin

Diagnostic

(DIAG)

30-Pin ECU

Connector

Left

Right

Front

Front

(LFT

(RHT

FRT)

FRT)

2-Pin Wheel

Speed Sensors

do not deform con-

Right

Rear
(RHT
RER)

Left
Rear
(LFT
RER)