Spicer CTIS Troubleshooting Guide
Spicer
®
CTIS
(
Central Tire Inflation System
Troubleshooting Guide
AXTS0015
)
July 2010
General Information
General Information
The description and specifications contained in the service
publication are current at the time of printing.
Dana reserves the right to discontinue or modify its models
and/or procedures and to change specifications at any time
without notice.
IMPORTANT NOTICE
This symbol is used throughout this
manual to call attention to procedures
where carelessness or failure to follow
specific instructions may result in
personal injury and/or component
damage.
Departure from the instructions, choice
of tools, materials and recommended
parts mentioned in this publication
may jeopardize the personal safety
of the service technician or vehicle
operator.
Any reference to brand name in this publication is made as an
example of the types of tools and materials recommended for
use and should not be considered an endorsement. Equivalents may be used.
WARNING: Failure to follow indicated
procedures creates a high risk of personal
injury to the servicing technician.
CAUTION: Failure to follow indicated
procedures may cause component
damage or malfunction.
IMPORTANT: Highly recommended
procedures for proper service of this unit.
Note: Additional service information not
covered in the service procedures.
Always use genuine Spicer replacement parts.
Every effort has been made to endure the accuracy of all information in this guide. However, Dana Commercial Vehicle
Systems Division makes no expressed or implied warranty
or representation based on the enclosed information.
Any errors or omissions may be reported to:
Marketing Services
Dana Commercial Vehicle Systems Division
P.O. Box 4097
Kalamazoo, MI 49003
Tip: Helpful removal and installation
procedures to aid in the service of this unit.
Table of Contents
Table of Contents
General Information
Central Tire Inflation System (CTIS) . . . . . . . . . . . . . . . 1
Key Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Component Description . . . . . . . . . . . . . . . . . . . . . . . . 2
Central Tire Inflation System Components . . . . . . . . . . 3
Simplified System Schematic . . . . . . . . . . . . . . . . . . . . 4
Operator Instructions
Flange or Panel
Operator Controls . . . . . . . . . . . . . . . . . . . . . . . . . 5
Warning Signals . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Driver Display Module (DDM)
Operator Controls . . . . . . . . . . . . . . . . . . . . . . . . . 9
Warning Signals . . . . . . . . . . . . . . . . . . . . . . . . . 10
Diagnostics
Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Service Codes Summary . . . . . . . . . . . . . . . . . . . . . . 14
Troubleshooting Tips . . . . . . . . . . . . . . . . . . . . . . . . . 20
Service Codes
No Code
Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Service Guidelines
CTIS Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
Joint Compounds and Fittings . . . . . . . . . . . . . . . . . . .59
Air Filter Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Wire Harness
Connector Illustrations . . . . . . . . . . . . . . . . . . . . . . . .61
M939 Wiring Diagram (676422 and 676603) . . . . . . . . 62
Flange Mount Wiring Diagram . . . . . . . . . . . . . . . . . . .63
Panel Mount Wiring Diagram . . . . . . . . . . . . . . . . . . . .64
Chassis ECU with DDM Wiring Diagram
Separate Power and Switched Ignition . . . . . . . . .65
All Power Switched . . . . . . . . . . . . . . . . . . . . . . . .66
Configuration Options . . . . . . . . . . . . . . . . . . . . . . . . .67
5 Flashing Lights or DDM – Dashes "--"
4 Flashing Lights or CHECK TIRES Flashing
2 Terrain Lights on Solid or DDM – Dashes "--"
No Terrain Lights or DDM – Dashes "--"
No Terrain Lights or DDM – Blank Display
DDM – Dashes "--"
Lights Sequentially Flashing
Solid Warning Lamp or Solid OVER SPEED
No Indication or DDM – Dashes "--"
No Indication
Low Pressure (Codes 26, 27) . . . . . . . . . . . . . . . 21
Low Air Supply (Code 32) . . . . . . . . . . . . . . . . . . 23
Atmospheric (Code 35) . . . . . . . . . . . . . . . . . . . . 25
Inflate Trend (Codes 36, 37) . . . . . . . . . . . . . . . . 27
Deflate Trend (Code 14) . . . . . . . . . . . . . . . . . . . 29
PCU Sensor (Codes 33, 34) . . . . . . . . . . . . . . . . 31
Pressure Switch (Code 31) . . . . . . . . . . . . . . . . . 33
Tire Leak (Imbalance) (Codes 44, 45) . . . . . . . . . 35
Tire Leak (Confirm) (Codes 41, 42) . . . . . . . . . . 37
Between Modes (Codes 23, 24) . . . . . . . . . . . . . 39
Deflate Signal (Codes 11, 12, 16) . . . . . . . . . . . . 41
PCU Solenoid (Supply, Deflate, Control, Front,
or Rear) (Codes 51, 52, 54, 55, 56) . . . . . . . . . . 43
Power (Code 17) . . . . . . . . . . . . . . . . . . . . . . . . . 45
Display Control Communications (Code 75) . . . . 47
Configuration Error . . . . . . . . . . . . . . . . . . . . . . . 49
Speed Signal (Codes 18, 76, 77) . . . . . . . . . . . . 51
Miscellaneous Output (Codes 53, 57, 58, 67, 68) 53
Wheel Valve Shut Off (Codes 61, 62, 64, 65) . . . 55
i
Central Tire Inflation System (CTIS)
General Information
Spicer’s Central Tire Inflation System features driver control of
tire air pressure through:
• Simple push button operation.
• Electronic braking priority for air system.
• Vehicle speed sensing and response capability.
• Self-diagnostics.
• Optional independent front and rear operation.
• Optional load selection.
Key Features
Depressurized Control Lines
The only time the system is pressurized is when changing tire
pressures or during pressure checks. Wheel valves isolate the
tires from the rest of the system.
Electronic Braking Priority
A pressure switch, installed in the supply tank, controls the
CTIS and use of air. This optimizes and protects the brake
system’s primary tank pressures during system operation.
Self-Diagnostic and Auto Shut-Down
The Spicer CTIS provides self-diagnosis during operation. If
the system detects a problem, it will display a series of flashing lights on the Electronic Control Unit (ECU) panel to alert
the
driver. If necessary, it will close the wheel valves and shut
down.
Diagnostic Capability
The Spicer CTIS provides for easy troubleshooting using
PC-based or industry standard tools. Personal computersupported diagnostics improve troubleshooting and reduce
maintenance time. The diagnostics provide for manual control
of CTIS test sequences and gives historical and active service
code data.
Speed/Pressure Control and Warning
If truck speed exceeds the maximum allowable speed for a
given setting, a panel-mounted light is activated by CTIS to
warn the driver. If speed is not reduced, the system
automatically inflates the tires to the appropriate pressure.
Manual Tire Inflation/Deflation
A valve stem has been included on each wheel valve, and may
be used for manual inflation, deflation, or measurement of tire
pressures.
Run Flat Operation
The CTIS normally checks tire pressures at intervals of 15
minutes. If possible tire damage is detected, the system will
activate Auto RUN FLA
check interval to 15 seconds, helping to assure that the tire
will remain inflated despite minor tire damage.
T. RUN FLAT reduces the pressure
1
CTIS Key Features
Component Description
General Information
Wheel Valve (WV)
All axles use a Wheel Valve (WV) at each end. Dual wheels are
typically connected to one WV to provide tire pressure
balance between duals. When the system is idle, the WV
isolates the tire(s). A standard tank valve is included for
manual inflation.
Quick Release Valve (QRV)
The Quick Release Valve (one per axle) receives pneumatic
signals from the Pneumatic Control Unit (PCU) and either
inflates the tires, or vents air from the tires causing them to
deflate. The QRV can be vented through the air stack to
provide for vehicle deep water fording.
Air Transport Valve (ATV)—Optional
The Air Transport Valve (ATV) may be added in-line between
the Wheel Valve and the tire. Its purpose is to manually lower
the tire pressure significantly, decreasing the height of the
vehicle, to allow the vehicle to be loaded onto planes, etc. with
low clearances.
Load Selection/Sensing—Optional
Electronic Control Unit (ECU)
The Electronic Control Unit (ECU) is the control center for the
entire Central Tire Inflation System. The ECU receives commands from the driver through push buttons, and transmits
and monitors appropriate signals throughout the system.
Pneumatic Control Unit (PCU)
The Pneumatic Control Unit (PCU) is a solenoid controlled
manifold that controls the air system. It also contains the PCU
sensor (transducer) which reads tire pressures.
Speed Sensor or Speed Input
Speed is read from the vehicle data link or a separate speed
sensor.
Pressure Switch (PS)
The Pressure Switch (PS) acts as an electronic brake priority
switch. It prevents the Central Tire Inflation System from
using air from the supply tank until the brake system is fully
charged. The PS also ensures that enough pressure exists for
the system to operate properly.
Some CTI systems make use of either a user selectable load
setting or an automatic load setting, which adjusts pressure
targets based on the load of the vehicle.
Air Lines
The Central Tire Inflation System uses a dedicated pneumatic
system plumbed from the vehicles’ exiting supply tank. Air
lines between the Pneumatic Control Unit and the Quick
Release Valves (QRV) are called “Upper Control Lines”. Air
lines between the QRVs and the Wheel Valves are called
“Lower Control Lines”.
2
General Information
RUN
FLAT
EM R
MPTY
MUD
SAND
S OW
PA T A L
L AD
CROSS
COUNTRY
FU L
LOAD
HIGHWAY
OVER SPEED
CHECK TIRES
Driver Display
Module
Chassis Mount
ECU
Electronic Control Unit (ECU)
• With separate operator controls
– or –
• With integrated operator controls
Pneumatic Control Unit
Pressure Switch
Air Transport Valve
(optional)
Wheel Valve
Quick Release Valve
Central Tire Inflation System Components
3
CTIS Components
Simplified System Schematic
Tire
Hose
Tire
Hose
To Steers
Pressure
Sensor
To D rive Axle 2
To D rive Axle 1
Load Sensor
(Optional)
Electronic
Control Unit
Pressure
Switch
To P rimary and
Secondary
Tanks
Single Channel System
System Key
Pneumatic – Upper Control Lines
Electrical
Wheel
Valve
Wheel
Valve
Compressor
Speed Sensor
Air Transport
Valve (Optional)
Air Transport
Valve (Optional)
Tire
Hose
Supply Tank
Air Dryer
Tire
Hose
Tire
Hose
Tire
Hose
Supply Line
PCU
Sensor
Supply Line
Pneumatic – Lower Control Lines
Pneumatic
Control Unit
Quick
Release
Valve
Quick
Release
Valve
Wheel
Valve
Wheel
Valve
Quick
Release
Valve
Wheel
Valve
Wheel
Valve
PCU
General Information
4
Flange or Panel—Operator Controls
RUN
FLAT
EMER
EMPTY
MUD
SAND
SNOW
PARTIAL
LOAD
CROSS
COUNTRY
FULL
LOAD
H GHWAY
OVER SPEED
CHECK TIRES
WARNING
RUN
FLAT
EMER
MUD
SAND
SNOW
CROSS
COUNTRY
HIGHWAY
OVER SPEED
CHECK TIRES
EMPTY
PART AL
LOAD
FULL
LOAD
Operator Instructions
The integrated push button/display is the primary interface for
display of system information and for push button entry of
system instructions. The following sections explain the
purpose and operation of the ECU controls and display.
Terrain Selection
These keys select pressures appropriate for different surface
conditions. Any mode may be selected at any time (within
built in speed limitations). Depressing the button for the
current mode will result in a pressure check.
HWY (Highway)—For operation on improved paved surfaces.
Load Selection (Optional)
This feature allows selection of pressures appropriate for
different vehicle load conditions (full load, partial-load,
empty). Switching the load setting will result in a pressure
check and subsequent changing of the pressures as
determined by the system.
Mode Annunciator Lights
The associated annunciator lights indicate the selected mode
and signal one of two states:
XC (Cross Country)—For operation on non-paved secondary
roads.
SAND (Sand)—For operation on trails and other unimproved
surfaces.
EMER (Emergency)—For selection of extremely low tire
pressures to help free a stuck vehicle, or to traverse a short
distance over a terrain known to require very low tire
pressures. Since this is an extremely low pressure, the
warning lamp will flash whenever this pressure is utilized.
The EMER key is for extreme conditions only and should not
be used for normal driving.
5
If the light is flashing:
The system is in the process of checking or changing pressures to attain the pressure(s) associated with that mode
light.
Some clicking may be heard from the PCU as the system
cycles to achieve the new pressure(s). A deflate will be
periodically interrupted as the system checks tire pressures to
determine how much further deflation is necessary.
Note: Adequate supply system pressure is required to begin
or continue any pressure changing sequence.
If the light is on steady:
The selected pressure has been achieved, the tires have been
isolated and the system is depressurized. The system will
cycle periodically to assure that tire pressure is maintained.
Note: The system is designed to allow tire pressure increase
due to heat buildup during vehicle use. This system will
not automatically deflate these pressure buildups—a
lower pressure mode must be selected to initiate a
deflate.
Operator Instructions
Flange or Panel
EMER
EMPTY
MUD
SAND
SNOW
PART AL
LOAD
CROSS
COUNTRY
FULL
LOAD
H GHWAY
OVER SPEED
CHECK TIRES
RUN
FLAT
CAUTION
Run Flat Key and Annunciator Light
This key instructs the system to check tire pressures at more
frequent intervals. This key also allows the operator to
override the “4 flashing lights” (tire leak imbalance) codes and
reattempt 2 lights and some 5 lights codes. (See Warning
Signals in next section). While the system is in RUN FLAT
mode, the RUN FLAT light will flash on and off. The “RUN
FLAT” feature will automatically deselect after 10 minutes, or
may be shut off by pressing the button a second time.
Selecting RUN FLAT to enable the system to inflate a significantly low tire may cause other tires on that channel to
temporarily lose pressure. This condition will be corrected
once the low tires is inflated to the pressure of the other
tires.
6
Operator Instructions
Single Terrain Light
• Flashing - System is working to achieve new pressures
associated with that mode light.
• Solid - Pressure is achieved, system is not active, and wheel
valves are closed.
2 Terrain Lights on Solid
System has shut off, closing wheel valves, with tire pressure
between two mode settings.
• Infl ating or defl ating tires is taking too long.
• CTIS is still operational.
• Select any mode button to re-attempt pressure change.
• On 2-channel systems, normal operation continues on
unaffected channel.
• Frequent occurrences may indicate need for service.
4 Terrain Lights Flashing or CHECK TIRES Flashing
Indicates low pressure in one or more tires. Stop vehicle and
identify damage.
• System shuts off, closing wheel valves, and waits for
operator instruction.
• T
ire damage i
s possible.
• CTIS should not be operated if major tire damage is found.
Repair tire before continuing to operate vehicle.
• On 2-channel systems, normal operation will continue on
the unaffected channel.
• If tire damage is minimal, operate CTIS by selecting RUN
FLAT.
Not
e: Repeated use of RUN FLAT to override mode light warnings
may result in tires infl ating higher than set point.
Note: Excessive air seal leakage on cold weather startup may
result in "4-5 Mode Lights" warning. If no tire damage exists, this
condition will self-correct as seals warm up with use.
5 Lights Flashing
System shuts off at least one channel due to fault detection on a
CTIS component.
• System closes wheel valves.
• System may periodically cycle PCU to determine if fault still
exists.
• On 2-channel systems, operation may be allowed on the
unaffected channel.
• Get service at next opportunity.
• No ability to override
system.
Several warning signals report operating problems. The Central Tire Infl ation System uses general sequences displayed
on the electronic control unit lights and an instrument panel-mounted warning lamp to identify the type and area of fault.
Flange or Panel—Warning Signals
7
Flange or Panel
RUN FLAT Flashing (with a Terrain Light)
RUN FLAT is selected, and tire pressures are checked at more
frequent intervals.
• If RUN FLAT is pushed to clear a "4 Mode Lights" fl ashing
display, imbalance and confi rmation fault detection is
overridden for the duration of RUN FLAT.
• Turn off by depressing RUN FLAT again or it will "time-out"
after 10 minutes.
Warning: RUN FLAT sho
uld not be used to infl ate tires with
substantial damage/defects. Use of RUN FLAT can result in other
tires on channel losing pressure.
No Terrain Lights
CTIS senses either a low system voltage or an electrical fault with a
Pneumatic Control Unit solenoid.
• System shuts off, closing wheel valves.
• Vehicle power i
s inadequate.
Flashing Warning Lamp and/or Buzzer or OVER SPEED Flashing
Vehicle speed is too fast for pressure selected.
• Reduce speed or select higher pressure by pressing
appropriate key.
• Continued operation in this mode will result in automatic
selection of more appropriate pressure setting.
• Warni
ng lamp may fl ash while system is in EMERGENCY
mode.
Solid Warning Lamp or Solid OVER SPEED
ECU has seen 25-50 ignition cycles without seeing any speed
signal.
• If no problem exists with speed circuit wiring or sensor,
lamp will go off when vehicle is moved.
Lights Sequentially Flashing (one after another)
A confi g uration error has occurred and the CTIS memory has been
"reloaded" from the system defaults.
• System reloads default confi g uration values.
• Pressing HWY and RUN FLAT butto
ns together may clear
display.
• Any past changes of target pressure, etc. should be
updated.
Lamp on
Instrument
Panel
Lamp on
Instrument
Panel
Operator Instructions
8
Operator Instructions
CAUTION
CAUTION
Driver Display Module—Operator Controls
Display
The Driver Display Module (DDM) uses a multi-function display to indicate the current selections. The display will show
HY for highway pressures, CC for cross-country pressures,
SS for mud-sand-snow pressures, and E for emergency pressures.
Note: The system is designed to allow tire pressure increase
due to heat buildup during vehicle use. It will not automatically deflate these pressure buildups.
Channel Indicators
Load Selection
Vehicle load selection is represented by a horizontal bar graph
under the mode display. Depress the load rocker switch to
change the selection, up for increasing load and down for
decreasing load.
Operating a loaded vehicle at unloaded tire pressures may
result in tire overheating and reduced tire life or blowout.
Terrain Selection
The terrain selection is changed by depressing the terrain
rocker switch, up to increase pressures and down to decrease
pressures. Any switch operation which does not change pressures will command the system to do a pressure check.
Tire pressures for the following terrains can be programmed
and may be selected by the operator:
• (HY) Highway - For travel on paved surfaces at
higher speeds.
The DDM indicates FRT or RR, respectively, for front or rear
axle groups. A flashing indicator identifies a group which is
changing or checking pressures. A solid indicator identifies a
group that has achieved target pressure.
Service Code Indication
The DDM will not display service codes directly but will display two dashes if service is required. (Accessing the service
codes requires a diagnostic tool). Also, a solid over speed
indicator identifies a loss of expected vehicle speed input.
• (CC) Cross Country - For reduced speed operation
on secondary roads.
• (SS) Mud Sand Snow - For reduced speed operation
on unpaved surfaces.
• (E) Emergency - For selection of extremely low tire
pressures to help free a stuck vehicle.
The Emergency selection is for extreme conditions only and
should not be used for normal driving.
9
Operator Instructions
Driver Display Module
Driver Display Module (DDM)—Warning
Signals
CTIS includes two distinct warnings to report possible tire
problems and inappropriate vehicle operation. You must take
immediate action to either reduce vehicle speed or check tire
condition whenever these warnings are displayed.
Over Speed Flashing
This signal reports that the vehicle speed is too fast for the
pressure selected. You must either reduce speed or select a
higher pressure by pressing the appropriate key. Continued
operation in this mode will result in the system automatically
selecting a more appropriate pressure setting.
Check Tire Flashing
This signal reports that one or more tires may be at a significantly lower pressure than the others and could indicate that a
tire is not holding pressure. Blinking channel indicators (FRT
or RR) indicate the fault location. Stop the vehicle immediately in a safe place and identify the extent of tire damage.
IMPORTANT
Tires can still go flat! Although the Central Tire Inflation System is designed to identify under-inflated tires and fill these
tires to the desired operating pressure, you can still expect
that tires will occasionally be punctured or otherwise damaged during normal use and no longer retain air reliably. A
daily walk-around inspection of the vehicle at the start of the
day, including a manual check of the tires, is still an important
responsibility of the vehicle operator. Tire damage is more
apparent after the vehicle has been idle overnight and will be
more difficult to detect visually once the CTIS equipped vehicle is in operation. Although observation of excessive inflation
periods through the driver interface can help identify a tire
problem, you should have damaged tires replaced prior to
placing the vehicle in operation.
10
Diagnostics
Diagnostics
This section covers the equipment and procedures used to
find and correct CTIS problems.
Test Equipment
CTIS troubleshooting can be performed at three levels:
1. PC diagnostics.
2. Handheld tester.
3. ECU warning signals (flashing light combinations).
Regardless of the testing equipment used, the
troubleshooting procedures will be based upon the diagnostic
service codes. Diagnostic tools offer the advantages of
computer-aided testing without interpreting service codes.
CTIS Diagnostics
The onboard system diagnostics are an important feature of
Spicer's CTIS. This section describes the use of service codes
to identify CTIS operating problems.
The CTIS uses a code to identify service issues. The codes
can be extracted from the ECU memory using a diagnostic
service tool equipped with the appropriate software. Refer to
the Service Codes Summary for more detailed information on
service codes.
Service Codes
Test Modes
Diagnostic tools allow the system to be placed in several
diagnostic modes:
Info—Display ECU information and configuration.
Codes—Active and historic codes are listed as reported by
the ECU.
Monitor (Normal)—CTIS operates normally, while status of
system components is observed.
Test—The following operations can be performed on each
channel (axle group):
• Check & Hold—System checks and
displays the pressures, then holds pressure in air
lines (quick test of control line and seal integrity).
• Deflate—System "manually" deflates (test the
deflation signal).
flate—System "manually" inflates (test for large
• In
leaks).
• Hold—Pressure is held in control lines (test for
small leaks).
Setup—Allows the technician to modify parameters such as
target tire pressures, etc.
Codes are described in the Service Codes Summary section.
Some service codes identify the component that is associated
with the problem. A list of possible causes is shown in order
of most likely occurrence.
In addition, the system stores service codes in the memory of
the ECU. These historical codes can only be accessed by a
diagnostic tool. Historical codes are automatically cleared
after 50 ECU resets with no active faults.
11
Diagnostics
Download free Dana Diagnostic
T
Note:
Windows 98 or newe
Connect to diagnostic
PC Diagnostics
CAUTION
A battery charger is not an adequate source of power.
Visit www.dana.com for free download of Dana Diagnostic
Tool (DDT).
PC diagnostics are easy to use and provide the quickest
diagnostic capabilities.
• Retrieve historical data, faults and tire pressures.
• Pressurize system to detect leaks.
• Access troubleshooting flowcharts and service
procedures.
Attach computer to RP1210A
communications box.
To use this program, an RP1210A compatible interface box
and cables are needed to connect the PC to the vehicle.
For these types of interface boxes to work with the Dana
Diagnostic Tool program, you must install a "RP1210 driver"
program provided by the manufacturer of the interface box.
If you do not have this program, it can normally be obtained
from the manufacturer's web site. Please contact the
manufacturer of your interface box if you have any questions
regarding this process.
connector.
ool from dana.com.
Program requires
r.
Diagnostics
Follow on-screen
instructions.
12
Diagnostics
Handheld Tester
A Prolink handheld tester may be used to read and clear
service codes and to obtain a short description of failures. The
tester can initiate test sequences for controller outputs and
can also read system parameters when equipped with the
Dana program card.
KEN MOORE
M RO P O E SOR Y T MS NC
Pro-Link
9
7 8
6
4 5
2 3
1
ENTER
0
FUNC
Multimeter
Based upon system schematics and aided by component
specific service codes, a multimeter can be used to check
sensor and solenoid resistances and to find wiring harness
faults. The multimeter can be used to check the Tire Pressure
Control System wiring and components for:
• Continuity
• Ground
• Broken wires
• Open circuits
• Shorted circuits
• Incorrect battery voltage
13
Service Codes Summary
Service Codes Summary
Diagnostics
The following chart provides a brief overview of the Central
Tire Inflation System (CTIS) service codes and the effect on
the system.
5 Flashing LIGHTs or
DDM – Dashes "--"
Low Pressure 26, 27 CHANNEL PRESSURE LOSS (Channel only checks pressures): Pressure check of
Low Air Supply 32 PRESSURE SWITCH REMAINS OPEN (System non-operative until switch closes):
Code No. Causes (numbered in order of likely occurrence)
given channel returns low reading (< 5 psig) indicating an extreme loss of pressure.
Repair and request pressure check to clear (press any mode button or run flat).
1) Open or broken line between PCU and wheel valve
2) Significant hub air seal leakage
3) Kinked or plugged line between supply tank and PCU
4) Faulty PCU sensor (ex. frozen water contamination)
5) PCU failure (supply off or control off)
6) Pressure switch failure (shorted closed)
For 4 minutes at vehicle speed > 20 mph pressure switch failed to close.
Repair and allow pressure switch to close to clear.
1) Compressor governor cutout set too low
2) Pressure switch unplugged, or open wire
3) Faulty pressure switch (failed open)
4) Faulty compressor
5) Broken, kinked, or plugged line from compressor to supply tank
Note: Any reference to a “channel” on a single-channel
system refers to all control lines and wheel ends.
Atmospheric 35 OUT OF RANGE ATMOSPHERIC READING (System waits to check pressures):
Atmospheric pressure check indicates vented PCU pressure is outside of valid
atmospheric range (5-20 psia).
Repair and request pressure check to clear (press any mode button or run flat).
1) Poor ground connection to PCU sensor
2) Faulty PCU sensor (ex, frozen water contamination)
3) Faulty PCU or blocked PCU exhaust vent
Inflate Trend 36, 37 INFLATE PRESSURE LOSS (System disables given channel): Given channel loses > 6
psi while inflating.
Repair and cycle ignition to clear.
1) Damaged tire or tire leakage
2) Leaking lines or seals
3) Faulty PCU (control solenoid off or additional channel stuck on)
Deflate Trend 14 FAILURE TO DEFLATE PROPERLY (System disables deflates): System gains >10 psi
pressure while attempting to deflate, or does not lower tires by even a small amount
of the intended change.
Repair and cycle ignition to clear.
1) Plugged or restricted PCU vent line
2) Faulty PCU relief valve
3) Poor ground connection to PCU sensor
4) Contaminated PCU
5) Faulty PCU
14
Service Codes Summary (continued)
Diagnostics
5 Flashing LIGHTs or
DDM – Dashes "--"
PCU Sensor 33, 34 NO PCU SENSOR READING (System non-operative): No sensor voltage to ECU.
Pressure Switch 31 PRESSURE SWITCH SHORTED or FAILED CLOSED (System waits to check pres-
Code No. Causes (numbered in order of likely occurrence)
Clears 5 seconds following a valid reading.
1) Sensor is electrically disconnected
2) Pressure signal wire (XDCR SIGNAL) is shorted to ground, or open
3) PCU sensor VREF wire is shorted to ground, or open
4) Faulty sensor
PCU SENSOR READING TOO HIGH (System non-operative): Sensor voltage higher
than allowed.
Clears 5 seconds following a valid reading.
1) Pressure signal wire (XDCR SIGNAL) is shorted to power or XDCR VREF
2) Faulty sensor
sures): Pressure switch is read as closed, but pressure check of supply tank
indicates insufficient air pressure to continue.
Repair and request pressure check to clear (press any mode button or RUN FLAT).
1) Wire to pressure switch shorted to ground
2) Faulty pressure switch (failed closed)
3) Faulty PCU (leaks air during supply tank check)
5 Flashing LIGHTs and
CHECK TIRES Solid
Inflate Trend 36, 37 INFLATE PRESSURE LOSS (System disables given channel): Given channel loses > 6
Code No. Causes (numbered in order of likely occurrence)
psi while inflating.
Repair and cycle ignition to clear.
1) Damaged tire or tire leakage
2) Leaking lines or seals
3) Faulty PCU (control solenoid off or additional channel stuck on)
15
Service Codes Summary
Service Codes Summary (continued)
Diagnostics
4 Flashing LIGHTs or
CHECK TIRES Flashing
Tire Leak (Imbalance) 44, 45 TIRES IMBALANCED (System only checks pressures on given channel): Pressure
Tire Leak (Confirm) 41, 42 CONFIRMATION FAILURE (System disables given channel): Given channel fails to
2 Terrain Lights on
Solid or DDM –
Dashes "--"
Code No. Causes (numbered in order of likely occurrence)
check indicates a tire on the given channel may be significantly lower than other tires
on same channel. RUN FLAT will override this fault.
1) Significant tire pressure loss (i.e. overnight leakdown)
2) Significant tire damage or leaks
3) Leaking lines or seals
4) Contaminated wheel valve filters
5) Restricted tire valve stem
6) Faulty wheel valve (leaking back through QRV)
7) Kinked or restricted control lines
confirm 10 times in a row.
RUN FLAT will override this fault.
1) Damaged tire or tire leakage
2) Leaking hose between wheel valve and tire
3) Faulty wheel valve (leaking back through QRV)
4) Restricted air passage between QRV and wheel valve
Code No. Causes (numbered in order of likely occurrence)
Between Modes 23, 24 SLOW INFLATE (Channel only checks pressures): Given channel takes too long(> 40
minutes) in active inflate (pressure switch closed) to achieve requested mode.
Repair and request pressure check to clear (any mode button or run flat).
1) Insufficient air supply
2) Contaminated wheel valve filters
3) Kinked, plugged, or leaking lines
SLOW DEFLATE (Channel only checks pressures): Given channel takes too long in
active deflate (> 20 minutes) to achieve requested mode.
Repair and request pressure check to clear (any mode button or run flat).
1) Contaminated wheel valve filters
2) Restricted tire valve stem
3) Leaking upper control lines
4) Faulty PCU relief valve
5) Restricted QRV exhaust
6) Restricted PCU vent line
16
Service Codes Summary (continued)
Diagnostics
2 Terrain Lights on
Solid or DDM –
Dashes "--"
Deflate Signal 11, 12, 16 INCORRECT DEFLATE PRESSURE: Deflate signal reads outside of configured range
No Terrain Lights or
DDM – Dashes "--"
PCU Solenoid 51, 52, 54,
Code No. Causes (numbered in order of likely occurrence)
for 30 seconds. If occurs during multi-channel deflate, system will reattempt deflates
on individual channels.
Repair and request pressure check to clear. (any mode button or run flat).
1) Faulty PCU relief valve
2) Leaking upper control lines
3) PCU internal leaks
4) Deflate solenoid poppet stuck in non-energized position
5) Poor ground connection to PCU sensor or faulty sensor
Code No. Causes (numbered in order of likely occurrence)
ELECTRICAL SOLENOID FAILURE (System non-operative): Solenoid fails electrical
55, 56
diagnostics for approximately 2 seconds.
Repair & cycle ignition to clear.
1) Solenoid or harness wire is shorted to ground
2) Solenoid or harness wire is shorted to power
3) Faulty solenoid
No Terrain Lights or
DDM – Blank Display
Power 17 POWER (System non-operative): After initialization, voltage drops below 18V for > 15
DDM – Dashes "--" Code No. Causes (numbered in order of likely occurrence)
Display Control
Communications
Code No. Causes (numbered in order of likely occurrence)
seconds.
Clears immediately when voltage > = 18V.
1) Low battery voltage
2) Poor ground connection to ECU
3) Poor power connection to ECU
75 NO COMMUNICATION TO DDM: ECU not receiving data from DDM user interface.
Repair to clear.
1) No data link connection to DDM (damaged harness wiring)
2) Faulty DDM
17
Service Codes Summary
Service Codes Summary (continued)
Diagnostics
Lights Sequentially
Flashing
Configuration Error N/A CONFIGURATION ERROR (System is “Limp-Home”): System has reloaded the system
Solid Warning Lamp
or Solid OVER SPEED
Speed Signal 18 NO SPEED SIGNAL (System operation is normal): ECU has been reset 25-50 times
Code No. Causes (numbered in order of likely occurrence)
defaults, eliminating any changes (target pressures, etc.) previously programmed via
a diagnostic tool. Pressing HWY and RUN FLAT at the same time may clear the
display...updated config data should be reprogrammed.
1) Configuration connector loose or missing
2) Faulty ECU (if repeatedly occurs)
Code No. Causes (numbered in order of likely occurrence)
without any speed input to ECU. Note: Fault will be set immediately on power up.
Any speed input (driving vehicle with good speed sense operation) will clear fault.
1) Vehicle has been started approximately 25-50 times without being moved (no
speed input).
2) Sensor is electrically disconnected
3) Either speed sense wire is open or shorted to ground
4) Faulty speed sensor
5) Sensor actuation failure (Tang broken/disconnected on mechanical sensor, or
incorrect gap on pole sensor)
6) Both speed sense wires are shorted together
76, 77 Expected data link message not received
No Indication or DDM
– Dashes "--"
Miscellaneous Output 53, 57, 58,
No Indication Code No. Causes (numbered in order of likely occurrence)
Wheel Valve Shut Off 61, 62, 64, 65LOSS OF PRESSURE DURING SHUT OFF:
Code No. Causes (numbered in order of likely occurrence)
SPARE OUTPUT OR COMPONENT FAILURE:
67, 68
1) Harness wire is shorted to ground
2) Harness wire is shorted to power
3) Faulty component
1) Wheel valve shut off failure
2) Air passage restriction
18
Diagnostics
Inaccurate Tire Pressures
May be caused by leaking control lines, clogged wheel valve
filters or valve stems, or closed Air Transport Valves.
Run Flat Definition
Pressing the RUN FLAT button once during normal system
operation puts the system in Run Flat Mode for 10 minutes
and causes several things to happen:
• The RUN FLAT light will flash along with the selected
mode light.
• A full pressure check (including atmospheric) is
requested.
• After 10 minutes Run Flat will automatically
deselect...OR... pushing RUN FLAT button again
will deselect it. It can be reselected by pressing the
button again after timeout.
• Tire pressures are checked at more frequent
intervals.
In addition, pressing the RUN FLAT button while the ECU is
displaying a “4 lights” flashing code will cause all “4 mode
lights” flashing codes (imbalance and confirmation) to be
overridden for the duration of RUN FLAT.
Note: ECU replacement—ECUs are NOT a typical cause of
problems. If an ECU is replaced, the system should be
carefully rechecked to make sure the problem has been
fixed, and does not reoccur.
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