Eaton Transmission FRLO-14410C Service Manual
Troubleshooting Guide
Lightning Series
TRTS0580
January 2008
FRLO-14410C-T2
FRLO-15410C
FRLO-15410C-T2
FRLO-16410C
FRLO-16410C-T2
FRLOF-14410C
FRLOF-14410C-T2
FRLOF-15410C
FRLOF-15410C-T2
FRLOF-16410C
FRLOF-16410C-T2
For parts or service call us
Pro Gear & Transmission, Inc.
1 (877) 776-4600
(407) 872-1901
parts@eprogear.com
906 W. Gore St.
Orlando, FL 32805
General Warnings
General Warnings
Before starting a vehicle:
1. Sit in driver’s seat
2. Place shift lever in neutral
3. Set the parking brake
working on a vehicle or leaving the cab with engine run-
Before
g:
nin
1. Place shift lever in neutral
2. Set parking brake
3. Block wheels
not release the parking brake or attempt to select a gear un-
Do
the air pressure is at the correct level.
til
parking the vehicle or leaving the cab:
When
1. Place shift lever in neutral
2. Set the parking brake
not operate if alternator lamp is lit or if gauges indicate low
Do
.
voltage
Suggested Tools
• Volt/Ohm Meter
SPX
/ Kent-Moore 1 (800) 328-6657
P/N
5505027
• PC-based Service Tool “ServiceRanger”
Contac
t your OEM
• Data Link Tester
Ea
ton Service Parts 1 (800) 826-4357
P/N MF-KIT-04
• Eaton Test Adapter Kit
SPX
/ Kent-Moore 1 (800) 328-6657
P/N J-43318
• 6-Pin Deutsch Diagnostic Adapter
/ Kent-Moore 1 (800) 328-6657
SPX
P/N
J-38500-60A
Related Publications
• TRIG-0580 - Lightning Installation Guide
• TRDR-0580 - Lightning Driver Instructions
• TRSM-0580 - Lightning Service Manual
more information call 1-800-826-HELP (4357) or visit
For
Roadranger.com.
www.
Table of Contents
Section 1: Basic Troubleshooting
Diagnostic Procedure for Lightning Models .............1-2
Operational Check List .............................................1-3
Basic System Troubleshooting ................................. 1-4
What To Do If The Transmission
Is Not Operating Properly ................................1-5
Retrieving Fault Information .....................................1-6
Fault Code Table for Lightning Transmission ...........1-7
Symptom Complaints ...............................................1-8
Air System Troubleshooting
Vehicle Air Supply Requirement .............................1-12
Air System - Overview ............................................1-13
Air System - ECU ...................................................1-14
Air System - Splitter Subsystem ............................1-15
Air System - Range Subsystem ..............................1-16
Clutch Housing Breather Leak Overview ................1-18
Clutch Housing Breather Leak ................................1-19
Transmission ECU Breather Leak Overview ............1-20
Transmission ECU Breather Leak ...........................1-21
Range Cylinder Test Overview ................................1-22
Range Cylinder Test ...............................................1-23
Splitter Cylinder Test Overview ..............................1-26
Splitter Cylinder Test ..............................................1-27
Electronic System Troubleshooting
Electrical System Requirements .............................1-30
Wiring Diagram ......................................................1-31
Pinouts ...................................................................1-32
Power-Up Sequence Test Overview .......................1-34
Power-up Sequence Test .......................................1-35
Electrical Pretest Overview .....................................1-38
Electrical Pretest ....................................................1-39
Shift Knob Test- No Fault Codes Overview .............1-42
Shift Knob Test- No Fault Codes ............................1-43
J-1587 Data Link Test Overview .............................1-46
J-1587 Data Link Test ............................................1-47
Section 2: Fault Isolation Procedures
Component Code 11(SID 254, FMI 12)
Transmission ECU ............................................ 2-1
Component Code 33 (PID 158 or 168, FMI 3 or 4)
System Voltage Fault ........................................ 2-3
Component Code 35 (SID 231, FMI 2)
J-1939 Data Link Test ...................................... 2-5
Component Code 36 (SID 48 or 49, FMI 2)
Position Sensor Test ...................................... 2-13
Component Code 43 (SID 36, FMI 4, 5, 6)
Low Range Solenoid ...................................... 2-15
Component Code 46 (SID 37, FMI 4, 5, 6)
Splitter Solenoid ............................................. 2-17
Component Code 48 (SID 35, FMI 4, 5, 6)
High Range Solenoid ...................................... 2-19
Component Code 58 (PID 191, FMI 2)
Output Shaft Speed Sensor ............................ 2-21
System Code 66 (SID 58, FMI 1)
Unconfirmed Torque Path .............................. 2-25
System Code 71 (SID 61, FMI 7)
Range or Splitter Stuck in Gear ...................... 2-29
Component Code 73 (SID 58, FMI 11)
Transmission Missed Synchronous ............... 2-31
System Code 74 (SID 14, FMI 7)
Engine Missed Synchronous .......................... 2-33
System Code 93 (SID 231, FMI 14)
J-1939 Engine Message Fault ......................... 2-33
Reverse Switch Test Overview ............................... 2-39
Reverse Switch Test .............................................. 2-40
Neutral Switch Test Overview ................................ 2-43
Neutral Switch Test ................................................ 2-44
Table of Contents
1-1
Fault Isolation Procedures
Diagnostic Procedure for Lightning Models
Key On
Service light
comes on for a
few seconds
then turns off
Yes
Retrieve active
fault codes
Active Codes?
No
(Code 25)
Retrieve inactive
fault codes
No
Yes
- Perform vehicle electrical test
- Perform "No service light test"
- Solid service light? - Replace ECU
- Perform vehicle electrical test
- Follow troubleshooting guide
diagnostics for all Actives Codes
- Clear Inactive Codes/test drive &
confirm code(s) have not reset
1-2
Inactive
Codes?
No
(Code 25)
Symptom?
No
Test Complete
Yes
Yes
- Record & clear inactive fault codes
- Verify complaints / test drive
- If fault code is reset after clearing,
perform vehicle electrical test, and
following diagnostics for symptom
driven faults
- Perform vehicle electrical test
- Perform pneumatic test
- Isolate transmission / clutch issues
- Follow basic troubleshooting/symptom
driven diagnostic procedures
Fault Isolation Procedures
Operational Check List
When operating properly, the lightning transmission will act in the following manner:
• Top-2 feature will not function with cruise control turned off.
• Service light flashes once at vehicle initial power up.
• Service light flickers at vehicle power down.
• Service light flashes continuously with an active fault code.
• Synchronizer will not trigger with key off.
• Synchronizer will not trigger in neutral with key on and vehicle stationary.
• Synchronizer will trigger with key on, vehicle stationary and lever moved into a high range gear.
• Synchronizer will not downshift into low range if lever is moved into a low range gear at too high of road speed.
• If started in a high range gear the vehicle accelerator pedal will be “dead”.
• If driver beats the range up-shift with lever movement to a high range gear the accelerator pedal is “dead” until synchronous is made.
• Splitter will not trigger with key off.
Fault Isolation Procedures
• Splitter will trigger with key on and in any lever position.
• Accelerator pedal is “dead” when splitter is up shifting if the driver attempts to accelerate before splitter synchronous is
made.
• Engine accelerates when splitter downshifts if the driver doesn’t control engine RPM for proper synchronous.
• Aggressive splitter shifts below 1100 engine RPMs and whenever the transmission has a fast deceleration of the output
shaft.
• Aggressive splitter shifts with clutch disengaged or foot resting on clutch pedal disengaging clutch switch.
• Aggressive splitter shifts with clutch switch wired improperly – check for engine brake and cruise control functionality.
1-3
Fault Isolation Procedures
Basic System Troubleshooting
Following is information to help a vehicle operator start basic troubleshooting of the transmission system.This is not a complete
list. In many cases, the vehicle needs to be evaluated by a trained and experienced transmission technician.
Problem Possible Causes
Growl/Rattle in a “float” or
coast condition.
At idle Check for damaged or defective master clutch, master clutch release bearing, or clutch linkage,
Growl/Rattle on a “pull” Check for engine problem, which would result in noise or excessive vibration.Check master clutch
Lever Check for loose or damaged shift lever, which may vibrate and cause noise. Check for components
All other conditions Check for loose clutch housing bolts. Check transmission oil for excessive metal particles, which
Problem Possible Causes
Hard Lever Shifting Check for damaged or binding shift lever or shift control system.Check for lever interference with
Check for damaged, worn, or defective driveshaft, support bearing, or u-joints, which would result
in noise or vibration. Check for improper vehicle ride height, which would cause improper u-joint
operating angles. Check for axle problem, which would result in noise or vibration. Check for tire
problem, which would result in noise or vibration.
which would result in noise or vibration. Check for loose components, brackets, exhaust system,
and hoses in transmission area, which would result in noise or vibration.
for defects in dampening devices.
added to the shift lever; such as, cruise control, which may vibrate and cause noise.
may indicate internal problem. Check for damaged or worn gearing.
cab floor. Check for upper or lower shift boot tugging on shift lever. Check for a defective or damaged master clutch, which would result in clutch drag. Check for improper clutch brake engagement. Check that proper shifting procedures are followed.
Problem Possible Cause
Transmission is operating
at higher than normal temperature
1-4
If transmission is equipped with an internal cooler, check for pinched engine coolant hoses or
closed shut off valves. See section on Operating Temperatures with Coolers. Check oil level.
Fault Isolation Procedures
What to Do if the Transmission is Not Operating Properly
If a problem occurs with the transmission or vehicle system, the transmission may not shift correctly. These effects may include:
• Harsh, slow, or grinding button only shifts.
• No button shifts (5 gear ratios only).
• No range shift (low range or high range gear ratios only).
The Service Light on the Shift Knob may be on continuously, may be flashing, or may not illuminate at all.
If the Transmission is Not Operating Properly, Try the Following Steps:
1. Check the dash air gauge to make sure at least 90 PSI is available in both primary and secondary air systems.
2. Try resetting the Transmission Electronic Control Unit (ECU) - See procedure below.
3. If vehicle and road conditions permit, you may be able to operate the transmission as a 5 speed (no button shifts).
Transmission Reset Procedure
In some cases, “resetting” the transmission Electronic Control Unit (ECU) can restore proper transmission operation. Use the following procedure to reset the ECU.
• When it is safe to do so, stop the vehicle.
• Place the transmission shift lever in neutral and turn the ignition key to the “off” position.
• Wait 5 seconds.
• Restart the engine.
• If the problem continues, proceed to page 9 and identify the symptom.
Transmission Diagnostics
The Lightning Series Transmission ECU has self-diagnostic capability. The transmission recognizes when a problem occurs and
“stores” the information about these problems (faults) in the ECU memory. This information can be retrieved by the following
methods:
• Retrieve basic fault information (flash codes) by counting flashes of the service light.
• Some OEM vehicles have an electronic dashboard, which displays fault information. Refer to the specific OEM chassis
operator instructions for the procedure.
• Connect an applicable hand-held or PC diagnostic tool to the vehicle’s SAE J-1587 diagnostic connector.
Fault Isolation Procedures
1-5
Retrieving Fault Information
Fault Isolation Procedures
The transmission Electronic Control Unit (ECU) turns on the
service lamp, located on the shift knob, in the event the ECU
detects an electronic fault and at initial power-up. Once the
ECU has successfully powered-up, the ECU turns off the service lamp. The power-up sequence usually takes a few seconds. The service lamp remains on continuously if the ECU
execution malfunctioned at power-up. The ECU begins code diagnostics only after the ECU has successfully powered-up. The
service lamp flashes steadily if the ECU has detected an Active
fault code.
Note: Any Active code detected at vehicle start-up immediately
starts flashing the service light on the shift knob.
The service light provides access to diagnostic fault information, which has been logged in the transmission ECU. The service light flashes a sequence of on/off pulses, which can be
translated into specific “flash codes”. The flash codes can then
be used to identify a specific fault in the transmission system.
Transmission faults are classified as either Active (current
problem) or In-Active (non-current problem). An Active fault is
logged when the ECU recognizes a problem with the transmission. During an Active fault, the service light flashes steadily or
may stay on continuously. If during vehicle operation, the
problem corrects itself, the service light stops flashing and the
fault is logged as an In-Active fault.
Retrieving In-Active Fault Codes:
1. Use the procedure to retrieve Active fault codes except, turn the key off and on four (4) times within five
seconds ending with the key in the on position.
2. Observe the flash sequence of the service light on the
shift knob. A one or two second pause separates each
stored code, and the sequence automatically repeats
itself after flashing all codes.
Clearing Fault Codes:
The following procedure clears all In-Active fault codes from
the ECU’s memory.
1. Place the shift lever in neutral.
2. Set the parking brakes.
3. Turn the ignition key on but do not start the engine.
4. Start with the key in the on position. Turn the key off
and on six (6) times within five seconds ending with
the key in the on position. The service light will flash
on for 5 seconds confirming the codes are cleared.
Example of Flash Codes
How to Retrieve Fault Codes
Retrieve Lightning fault codes by enabling the Lightning system’s self-diagnostic mode.
Note: You can also use a P.C. based diagnostic tool such as
ServiceRanger to retrieve fault codes.
Retrieving Active Fault Codes:
1. Place the shift lever in neutral.
2. Set the parking brakes.
3. Turn the ignition key on but do not start the engine.
4. Starting with the key in the on position. Turn the key
off and on two (2) times within five seconds ending
with the key in the on position.
5. Observe the flash sequence of the service light on the
shift knob. Flash codes may take 5 seconds to begin
flashing. A one or two second pause separates each
stored code, and the sequence automatically repeats
itself after flashing all codes.
Fault Code 35 Fault Code 11
Short Pause Long Pause Short Pause
Service Light
1-6
Fault Isolation Procedures
Fault Code Table for Lightning Transmission
Component Fault Codes*
Flash
Code
11 Transmission ECU 130 254 12
25 No Codes 130
33 Ignition/Battery Voltage Low or High 130 158 or 168 3 or 4
35 Engine to Transmission J1939
36 Shift Lever Position Sensor 130 48 or 49 2
43 Low Range Shift Solenoid 130 36 4, 5, or 6
46 Splitter Shift Solenoid 130 37 4, 5, or 6
48 High Range Shift Solenoid 130 35 4, 5, or 6
58 Output Speed Sensor 130 191 2
Description MID PID SID FMI
130 231 2
Communication Link
System Fault Codes **
Flash Code Description MID PID SID FMI
66 Unconfirmed Torque Path (Input speed and
output speed do not equal known gear ratio)
71 Splitter or Range Stuck in Gear 130 61 7
130 58 1
Fault Isolation Procedures
73 Transmission Missed Synchronization 130 58 11
74 Engine/Transmission Missed
Synchronization
93 J-1939 Engine Message Fault 130 231 14
*Component Fault Codes specifically isolate problems that may arise with the electronic components used in the Lightning series
transmissions. These codes occur at initial vehicle power-up if not induced by intermittent vibration or heat problems.
**System Fault Codes specifically isolate problems that may arise from a mechanical or pneumatic problem that has prevented
or missed a shift in the Lightning transmission. System fault codes are only active during vehicle operation and are not detected
at initial vehicle power-up.
Note: System fault codes also indicate problems with other components that affect the performance of the transmission such as
low air pressure. Troubleshoot the code properly to isolate the component causing the fault to become active.
130 14 7
# Hand Held Codes
MID – Message ID Assignment. In this case, MID 130 represents the transmission.
PID – Parameter ID Assignment. Generally represents a status or value.
SID – Subsystem ID Assignment. Identifies a failure in a subsystem.
FMI – Failure Mode ID. Describes the type of failure detected in the subsystem
1-7
Fault Isolation Procedures
Symptom Complaints
Symptom Possible Condition Remedy Reference
No service light Electrical circuit is open,
grounded, or blown VIGN fuse
or faulty light
Service light on continuously Light circuit grounded to VBATT,
transmission performance not
affected
Transmission ECU internal failure;
3 speed operation only;
No splitter or range shifts
Top 2 option not functioning Cruise control turned off Turn on cruise control.
Top 2 option stops functioning
as a result of another problem
No button shifts after cruise control if turned off while in Top 2
mode
Hold Mode Normal Operation. Lever must be
No fault codes set. Performance of
transmission not affected by nonfunctioning light. Check fuse then if
necessary, perform service light
test.
Repair vehicle wiring harness.
Perform vehicle electrical test, if OK
- replace transmission ECU.
Repair for other faults such as Output Speed Sensor Position Sensor.
Look for other complaints such as
engine brake or cruise not functioning.
cycled through neutral to regain button function.
Harsh or aggressive splitter shifts ECU Malfunction Active Fault Code 11. page 1
Before proceeding, see note at
bottom of page.
(any shift using the splitter button) Engine Missed Synchronization Active Fault Code 74. page 33
Grinding or Raking Splitter Shifts Out-Of-Synchronous or shifts
(Shifts from 1st to 2nd, 3rd. to 4
th, 5th to 6th, 7 th to 8 th, and 9 th
to 10th. Shift grinds but engages.)
Position Sensor Malfunction Active Fault Code 36. page 13
Lever/Splitter shifts attempted in an
Engine Synchronous speed outof-limit of operating range
Low or high air pressure Faulty Air Regulator.
Splitter leak or partial blocked air
system
Driver resting foot on Clutch
Pedal so as to disengage clutch
switch but still has clutch engaged
out-of-synchronous condition. Re-
view Driver Instruction Book -
TRDR-0580 - for proper driving
techniques.
Perform Splitter Cylinder Test. page 26
Remove foot from clutch pedal ex-
cept when necessary to shift, start or
stop the vehicle.
1-8
Fault Isolation Procedures
Symptom Possible Condition Remedy Reference
Clutch Switch Contamination
built up on switch, for example,
dirt, ice, etc. or Mechanical
Clutch Linkage
Note: Aggressive splitter shifts may occur normally under the following conditions.
1. Low speed splitter shifts below 1100 RPMs. - This is normal operation.
2. Splitter shifts on grades with heavily loaded vehicle. - This is normal operation.
3. Anytime the vehicle has a fast deceleration of the transmission output shaft. For example, making a hard left-hand turn
and moving the splitter at the same time. - This is normal operation.
Symptom Possible Condition Remedy Reference
Harsh shifts (Lever Only) Out-Of-Synchronous Shifts Lever shifts attempted in an out-of-
(Skip shifts. i.e. 1 st to 3 rd., or 3
rd. to 5 th.)
Clutch Drag Adjust Clutch and check for clutch
Clutch Brake Check for improper clutch brake en-
Cruise control and engine brake is
also inoperative when the clutch
switch malfunctions. Refer to OEM
manual for troubleshooting clutch
switch.
synchronous condition. Review Driver’s Instruction Book for proper techniques.
slippage and drag.
gagement.
Fault Isolation Procedures
Slow/grinding/raking or inoperative Range Shift (Shift from 6 th to
7 th or from 7 th to 6 th.)
Five speed transmission. (Only
Even or Odd Numbered Gears.)
Low or High Air Pressure Perform Range Cylinder Test. page 22
Air System Leaks
Reduced Air Flow
Damaged Mechanical parts internal to the transmission
ECU Malfunction Active Fault Code 11. page 1
Unconfirmed torque path
through transmission
Splitter stuck in gear Active Fault Code 71. page 29
Output Speed Sensor Malfunction
Splitter System Air Leak Perform Splitter Cylinder test. page 26
Shift Knob Malfunction No Active Fault Codes. Perform Shift
Active Fault Code 66. page 25
Review Air System Overview. page 13
Repair for damaged internal parts.
Perform Output Shaft Speed Sensor
test.
Knob test.
page 21
page 42
1-9
Fault Isolation Procedures
Symptom Possible Condition Remedy Reference
Six speed transmission. (Only 1st
through 6th gears.)
Splitter Solenoid Short or Open Active Fault Code 46. Perform Sole-
noid test.
Loss of communication with
engine
Range system air leak Perform Range Cylinder test. page 22
Position sensor malfunction Active Fault Code 36. page 13
Low Range Solenoid Malfunction
High Range Solenoid Malfunction
Range stuck in gear. Active Fault Code 71. page 29
Transmission missed synchronous.
High Range Synchronizer Mechanical Failure
Active Fault Code 35 and gears 1, 3, 5,
7, 9. J-1939 communication link broken.
Active Fault Code 43. page 15
Active Fault Code 48. page 19
Active Fault Code 73. page 31
Perform Range Cylinder test prior to
disassembly, then replace damaged
synchronizer parts if required. Refer
to “Synchronizer” repair strategy item
TRSM-0915 (Note: after 12/31/04 this
publication will be TRMT-0001) for
repair details.
page 17
page 5
page 22
Four Speed Transmission. (Only 7
th through 10 th gears.)
Three Speed Transmission (Only
1 st, 3 rd., 5 th gears)
Low Range Solenoid Malfunction
Range System Air Leak Perform Range Cylinder test. page 22
High Range Solenoid Malfunction
Range stuck in gear. Active Fault Code 71. page 29
Low Range Synchronizer Mechanical Failure
Low System Voltage Active Fault Code 33. page 3
Loss of air pressure to transmission.
ECU Malfunction. Active Fault Code 11. page 1
Active Fault Code 43. page 15
Active Fault Code 48. page 19
Perform air system test prior to disassembly, then replace damaged synchronizer parts if required. Refer to
“Synchronizer” repair strategy item
TRSM-0915 (Note: after 12/31/04 this
publication will be TRMT-0001) for
repair details.
Check vehicle air pressure.
Service light on continuously. Replace
ECU.
1-10
Fault Isolation Procedures
Symptom Possible Condition Remedy Reference
Software download unsuccessful
Two Speed Transmission (only 7
th, 9 th gears)
Neutral Switch Wheel Chair Lift / PTO etc. not
Reverse Switch Reverse Light / Beeper not
ECU malfunction service light
on continuously
operating
Engine will not crank (some applications)
functioning.
Replace ECU.
Replace ECU.
Perform Neutral Switch Test per OEM
recommendations.
Perform Neutral Switch Test per OEM
recommendations.
Perform Reverse Switch Test per
OEM recommendations.
Fault Isolation Procedures
1-11
Fault Isolation Procedures
Vehicle Air Supply Requirement
The transmission filter/regulator assembly provides the inlet port for transmission supplied air. You will find the filter/regulator
located at the rear of the transmission on the driver’s side of the truck. The filter/regulator assembly regulates the transmission
supply to 80 PSI (551 kPa) maximum.
Filter / Regulator
Inlet Air Pressure Required 90-130 PSI (620-896 kPa)
Air Dryer Required
Inlet Port Size SAE 3/8” – 18 NPT
1-12
Fault Isolation Procedures
Air System - Overview
The Lightning series transmission uses an automatically controlled range cylinder to manage the air operated range shift between
6th and 7th gear. The button on the shift knob controls the splitter shift. Splitter shifts occur every time the transmission shifts
consecutive from one gear to the next gear or when the button is moved from one state to the next.
The simple block diagram below shows the relationship between the air system and electronic controls.
Splitter Signal from Shift Knob
Engine Communication (J1939)
Diagnostic Communication (J1587)
H
L
Non-Contacting Sensor to
sense desired range position
ECU
Splitter
Range
H L S
Charge Air
Constant Air
Solenoid
Pak
Output Speed
Sensor
The Lightning series transmission utilizes an electric over air concept for actuating the splitter and range cylinders. An electric
signal is sent to the ECU. The ECU then, enables a solenoid valve, which in turn directs air to the appropriate cylinder. A switch in
the shift knob directs the splitter shift. The position of the switch indicates to the ECU the desired splitter state. The ECU makes
the shift automatically when the proper conditions are achieved. The signal to the ECU for a range shift is automatically made when
the shift lever passes from the middle rail (6th gear) to the outside rail (7th gear). A sensor detects the movement and signals the
ECU to actuate the range valve. As with the splitter shift, the range shift only occurs when a specific set of conditions is achieved.
Fault Isolation Procedures
1-13
Fault Isolation Procedures
Air System - ECU
The transmission’s electronic control unit (ECU) activates solenoids in the ECU, which opens up internal air passages. The transmission air filter/regulator is the only external air system component.
The air moves through passages internal to the transmission and the seal plate of the ECU. The illustration below shows the air
passages as viewed through the ECU.
Splitter Diagnostic Port
Supply to Valves
Range HI
Diagnostic Port
To HI Range
Splitter
80 PSI Supply
from Regulator /
Constant Air
to Splitter
To Splitter
Cylinder
Range Cylinder
O-ring
Seal Plate
Range
Supply to
Valves
HI Range Valve
LO Range Valve
Splitter Valve
From Splitter Valve
To LO Range
1-14
Splitter Cylinder
O-rings
Exploded View of Air System
Electronic Control Unit
(ECU)
Fault Isolation Procedures
Air System - Splitter Subsystem
The ECU controls the operation of the splitter solenoid function, responding to driver input from the splitter button on the shift
knob or Top-2 operation.
The splitter cylinder has three distinct positions, forward (overdrive), rear (direct) and intermediate (neutral). The forward position
is achieved by activating the splitter solenoid valve, which applies air pressure to the rearward side of the piston. This is the splitter
state for the even numbered gears (2, 4, 6, 8 and 10)
The rearward position is achieved by de-activating the splitter solenoid valve, which exhausts the air pressure from the rearward
side of the splitter piston. The constant air pressure then forces the piston rearward. This is the splitter state for the odd numbered
gears (1, 3, 5, 7 and 9).
The intermediate or neutral state is achieved by the ECU rapidly turning on and off the splitter solenoid valve. This condition results
in a pressure on the rearward side of the splitter piston that is between 0 and full system pressure. This neutral state is used to
allow the gears to synchronize prior to engagement, thereby significantly improving the shift quality.
Constant Air Pressure
Splitter in
Direct
Constant Air Pressure
Constant Air Pressure
Signal Air Pressure
Splitter in
Overdrive
Fault Isolation Procedures
Signal Air Pressure
Splitter in
Neutral
1-15
Fault Isolation Procedures
Air System - Range Subsystem
The ECU controls the operation of all range solenoid valve functions. The driver’s movement of the shift lever accomplishes a
change in the position of the range from high range to low range or vice versa.
The range piston has two distinct positions. Both the forward and rearward positions are a function of mechanical stops. Only one
side of the piston has air pressure at any one time. The ECU automatically selects either high or low range as the lever passes
through neutral when making an up-shift from 6th gear to 7th gear or the downshift from 7th gear to 6th gear.
In either case, the distinct sound of the range shifting is audible outside the cab, standing next to the stationary truck.
Air
Pressure
Low Range High Range
HI
R
LO
R
2
1
Low Range
3
5
8
4
7
10
6
9
High
Range
Pressure
Air
1-16
Fault Isolation Procedures
This page left blank intentionally.
Fault Isolation Procedures
1-17
Fault Isolation Procedures
Clutch Housing Breather Leak Overview
Overview
Air leaks out the breather located on top of clutch housing.
An air operated PTO with an air leak can pressurize the
transmission and cause air to leak out the transmission
breather.
Detection
Audible Air Leak
Fallback
There is no fallback mode for this failure.
Possible Leak Paths
Required Tools
• Basic Hand Tools
Possible Causes
• Splitter Cylinder O-Rings
• Range Cylinder O-Ring
• Air operated PTO leak
1-18
Splitter Cylinder Range Cylinder
Fault Isolation Procedures
Clutch Housing Breather Leak
Step A Procedure Condition Action
1. Key on.
2. Vehicle stationary and secured,
air system fully charged, engine
not running.
3. Listen for air leaking
out the breather while
moving the shift lever
to make the range
cylinder shift from low
range to high range.
When stationary, the
lever must be moved
in and out of a high
range gear to make the
synchronizer shift.
Note: Oil leaking out the
breather may be a sign
indicating an air leak
internal to the
transmission.
Air leaks in both positions Repair the splitter cylinder, and
replace all cylinder o-rings. Go to
Step V.
Air leaks only in low
range
Repair the range cylinder, and
replace all cylinder o-rings. Go to
Step V.
Step V Procedure Condition Action
1. Fully charge air
system on vehicle and
check for
effectiveness of repair.
Breather still leaks Go to Step A.
Breather does not leak Test Complete.
Clutch Housing Breather
Leak
1-19
Fault Isolation Procedures
Transmission ECU Breather Leak Overview
Overview
Air leaks out the breather on the ECU.
The breather exhausts a slight amount of air every time
the transmission makes a range shift and when the splitter
shifts to any odd numbered gear.
Detection
Audible Air Leak.
Fallback
There is no fallback mode for failure.
Possible Leak Paths
Required Tools
• Basic Hand Tools
Possible Causes
This fault can be caused by any of the following:
• Splitter or Range Cylinder O-rings
• Solenoid Seals or O-rings (ECU)
• Seal Plate
Possible Leak Path
1-20
Splitter Cylinder Range Cylinder
Solenoid
(Non-Serviceable - Inside ECU)
Fault Isolation Procedures
Transmission ECU Breather Leak
Step A Procedure Condition Action
1. Key on, vehicle stationary and
secured, air system fully
charged, engine not running.
2. Cycle the splitter
cylinder by moving the
button on the shift
knob from the down
position to the up
position.
Leak stops with the
button in the up position.
Leaks in either position Go to Step B.
Replace the splitter cylinder orings and clean out any
contamination in the cylinder. If leak
continues after making this repair,
then replace the transmission ECU
and seal plate. Go to Step V.
Step B Procedure Condition Action
1. Key on, vehicle stationary and
secured, air system fully
charged, engine not running.
2. Cycle the range
cylinder by moving the
shift lever into high
range (the 7/8 gear
position) then back into
neutral. The
synchronizer makes a
distinct audible noise
when shifting.
Leak stops when in high
range.
Leak stops when in low
range.
Replace the range cylinder piston
and clean out any contamination in
the cylinder. If leak continues after
making this repair, then replace the
transmission ECU and seal plate.
Go to Step V
Replace the range cylinder piston
and clean out any contamination in
the cylinder. If leak continues after
making this repair, then replace the
transmission ECU and seal plate.
Go to Step V.
Transmission ECU
Breather Leak
Step V Procedure Condition Action
1. Charge the vehicle air
system and test
repairs for
effectiveness.
No Leaks Test Complete
Air still leaks out breather
on ECU.
Repeat test procedures for air leaks.
1-21
Fault Isolation Procedures
Range Cylinder Test Overview
Overview
The range cylinder test does not relate to any specific fault
code, but must be performed prior to disassembly of the
transmission if a range system mechanical failure is suspected. The range cylinder test verifies the basic air system inputs are operating correctly, before proceeding with
disassembly. The driver complaint must be confirmed or
duplicated before preceding with the testing.
Detection
There is no detection process specifically for the Range
Cylinder. However, failures of this type are generally detected by the driver as a symptom such as the transmission range shift may grind, rake, or fail to operate.
Fallback
There is no fallback for the Range Cylinder Test.
Required Tools
• Basic Hand Tools
Possible Causes
This fault can be caused by any of the following:
• Truck air pressure out of range
• Faulty air/filter regulator
• Air system contamination
• Friction material worn or damaged on synchronizer
• Other internal mechanical failure
1-22
Fault Isolation Procedures
Range Cylinder Test
Step A Procedure Condition Action
1. Start vehicle and
build up air pressure
to maximum. Shut off
vehicle.
Vehicle's primary and
secondary air supply is
less than 90 PSI or leaks
down
Vehicle air pressure is
Repair vehicle's air system and go
to Step V.
Go to Step B.
greater than 90 PSI and
no leaks.
Step B Procedure Condition Action
1. Drain air tanks to prevent injury.
2. Remove one of three plugs in
transmission filter/regulator and
insert pressure gauge.
3. Start vehicle and build
up air pressure to
maximum. Shut off
vehicle.
Front of
Transmission
Transmission filter/
regulator pressure less
than or greater than 77 to
82 PSI.
Regulator pressure
between 77 and 82 PSI.
Air Inlet
Port
Replace filter/regulator
assembly. Go to Step V.
Go to Step C.
Filter / Regulator
Range Cylinder Test
Regulated
Air Pressure
1-23
Fault Isolation Procedures
Range Cylinder Test, continued
Step C Procedure Condition Action
1. Drain air tanks to prevent injury.
2. Remove either the plug for the
high range test port or low range
test port located on the top of
the transmission and insert
pressure gauge.
3. Start vehicle and build up air
pressure to maximum. Shut off
vehicle.
4. Key in the on position, do not
start vehicle.
5. Have an assistant move the
lever to cycle the range cylinder
by moving the lever in and out of
a high range gear position.
6. Watch the reaction of
the pressure gauge
and listen for the range
to shift.
Gauge response is
sudden and immediate.
Gauge reads between 77
to 82 PSI and the distinct
sound of the range
shifting is audible.
Gauge is slow to respond
or the range shift is not
audible.
Go to Step D.
Remove transmission ECU and
clean out any contamination in air
passages or cylinders. Go to Step
V.
Splitter Test Port
High Range Test Port
Low Range Test Port
1-24
Clean the area around the plugs prior
to removal to prevent dirt or other
contamination from falling into the
ports after removing the plugs.
Fault Isolation Procedures
Range Cylinder Test, continued
Step D Procedure Condition Action
1. Remove and disassemble
transmission.
2. Inspect all
synchronizer parts.
Synchronizer parts
excessively worn or
damaged. Refer to
publication TRSM-0915
for synchronizer
replacement guidelines.
No parts worn or
damaged
Replace damaged parts. Go to Step
V.
Go to Step V.
Step V Procedure Condition Action
1. Start vehicle and road
test to determine
repair effectiveness.
Range shifts properly Test complete
Range still grinds/rakes
or inoperative
Repeat test procedures
1-25
Range Cylinder Test
Fault Isolation Procedures
Splitter Cylinder Test Overview
Overview
The Splitter Cylinder Test does not relate to any specific
fault code, but must be performed prior to disassembly of
the transmission if a splitter system mechanical failure is
suspected. The splitter cylinder test verifies the basic air
system inputs are operating correctly, before proceeding
with transmission disassembly.
Required Tools
• Basic Hand Tools
Possible Causes
Detection
There is no detection process specifically for the splitter
cylinder. However, failures of this type are generally detected by the driver as a symptom such as the transmission splitter shift may grind, rake, or fail to operate. The
driver complaint must be confirmed or duplicated before
proceeding with the testing.
Fallback
There is no fallback for the Splitter Cylinder Test.
This fault can be caused by any of the following:
• Truck air pressure out of range
• Faulty air/filter regulator
• Air system contamination
• Faulty shift knob / splitter switch or
vehicle wiring
• Internal mechanical failure
1-26
Fault Isolation Procedures
Splitter Cylinder Test
Step A Procedure Condition Action
1. Review driver's instruction for
proper driving technique.
2. Test drive truck with
operator.
Driver operating splitter
improperly
Driver operating splitter
Provide instruction and end test.
Go to Step B.
properly
Step B Procedure Condition Action
1. Start vehicle and build
up air pressure to
maximum. Shut off
vehicle.
Vehicle's primary and
secondary air supplies
less than 90 PSI or leaks
down
Vehicle air pressure is
greater than 90 PSI and
no leaks
Repair vehicle's air system and
go to Step V.
Go to Step C.
Step C Procedure Condition Action
1. Drain air tanks to prevent injury.
2. Remove one of three plugs in
transmission filter/regulator and
insert pressure gauge.
Splitter Cylinder Test
3. Start vehicle and build
up air pressure to
maximum. Shut off
vehicle.
Front of
Transmission
Regulated
Air Pressure
Filter / Regulator
Air Inlet
Port
Transmission filter/
regulator pressure less
than or greater than 77 to
82 PSI
Regulator pressure
between 77 and 82 PSI
Replace filter/regulator assembly.
Go to Step V.
Go to Step D.
1-27
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