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

[phone] [e-mail]

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

Before working on a vehicle or leaving the cab with engine running:

1.Place shift lever in neutral

2.Set parking brake

3.Block wheels

Do not release the parking brake or attempt to select a gear until the air pressure is at the correct level.

When parking the vehicle or leaving the cab:

1.Place shift lever in neutral

2.Set the parking brake

Do not operate if alternator lamp is lit or if gauges indicate low voltage.

Suggested Tools

•Volt/Ohm Meter

SPX / Kent-Moore 1 [phone] P/N 5505027

•PC-based Service Tool “ServiceRanger” Contact your OEM

•Data Link Tester

Eaton Service Parts 1 [phone] P/N MF-KIT-04

•Eaton Test Adapter Kit

SPX / Kent-Moore 1 [phone] P/N J-43318

•6-Pin Deutsch Diagnostic Adapter SPX / Kent-Moore 1 [phone] P/N J-38500-60A

Related Publications

•TRIG-0580 - Lightning Installation Guide

•TRDR-0580 - Lightning Driver Instructions

•TRSM-0580 - Lightning Service Manual

For more information call 1-800-826-HELP (4357) or visit www.Roadranger.com.

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 TestNo Fault Codes Overview .............	1-42
Shift Knob TestNo 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

Contents of Table

1-1

Fault Isolation Procedures

Diagnostic Procedure for Lightning Models

Key On

Service light	No	- Perform vehicle electrical test
comes on for a
few seconds		- Perform "No service light test"
then turns off		- Solid service light? - Replace ECU

Yes

Retrieve active fault codes

Yes	- Perform vehicle electrical test
	- Follow troubleshooting guide
Active Codes?	diagnostics for all Actives Codes
	- Clear Inactive Codes/test drive &
	confirm code(s) have not reset
No
(Code 25)
Retrieve inactive
fault codes

Inactive

Codes?

No

(Code 25)

	- Record & clear inactive fault codes
Yes	- Verify complaints / test drive
	- If fault code is reset after clearing,
	perform vehicle electrical test, and
	following diagnostics for symptom
	driven faults

Yes	- Perform vehicle electrical test
	- Perform pneumatic test
Symptom?	- Isolate transmission / clutch issues
	- Follow basic troubleshooting/symptom
	driven diagnostic procedures
No
Test Complete

1-2

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 synchro-
		nous is made.
	•	Splitter will not trigger with key off.
			Fault
	•	Splitter will trigger with key on and in any lever position.
	•	Engine accelerates when splitter downshifts if the driver doesn’t control engine RPM for proper synchronous.	Isolation
	•	Accelerator pedal is “dead” when splitter is up shifting if the driver attempts to accelerate before splitter synchronous is
		made.	Procedures
	•	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	Check for damaged, worn, or defective driveshaft, support bearing, or u-joints, which would result
coast condition.	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.
At idle	Check for damaged or defective master clutch, master clutch release bearing, or clutch linkage,
	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.
Growl/Rattle on a “pull”	Check for engine problem, which would result in noise or excessive vibration.Check master clutch
	for defects in dampening devices.
Lever	Check for loose or damaged shift lever, which may vibrate and cause noise. Check for components
	added to the shift lever; such as, cruise control, which may vibrate and cause noise.
All other conditions	Check for loose clutch housing bolts. Check transmission oil for excessive metal particles, which
	may indicate internal problem. Check for damaged or worn gearing.

Problem	Possible Causes
Hard Lever Shifting	Check for damaged or binding shift lever or shift control system.Check for lever interference with
	cab floor. Check for upper or lower shift boot tugging on shift lever. Check for a defective or dam-
	aged master clutch, which would result in clutch drag. Check for improper clutch brake engage-
	ment. Check that proper shifting procedures are followed.

Problem	Possible Cause
Transmission is operating	If transmission is equipped with an internal cooler, check for pinched engine coolant hoses or
at higher than normal tem-	closed shut off valves. See section on Operating Temperatures with Coolers. Check oil level.
perature

1-4

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.

Procedures Isolation Fault

1-5

Fault Isolation Procedures

Retrieving Fault Information

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.

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.

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

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	Description	MID	PID	SID	FMI
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	130		231	2
	Communication Link
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

System Fault Codes **

Flash Code	Description	MID	PID	SID	FMI
66	Unconfirmed Torque Path (Input speed and	130		58	1
	output speed do not equal known gear ratio)
71	Splitter or Range Stuck in Gear	130		61	7
73	Transmission Missed Synchronization	130		58	11
74	Engine/Transmission Missed	130		14	7
	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.

# 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

Procedures Isolation Fault

1-7

Fault Isolation Procedures

Symptom Complaints

Symptom	Possible Condition	Remedy		Reference
No service light	Electrical circuit is open,	No fault codes set. Performance of
	grounded, or blown VIGN fuse	transmission not affected by non-
	or faulty light	functioning light. Check fuse then if
		necessary, perform service	light
		test.
Service light on continuously	Light circuit grounded to VBATT,	Repair vehicle wiring harness.
	transmission performance not
	affected
	Transmission ECU internal fail-	Perform vehicle electrical test, if OK
	ure;	- replace transmission ECU.
	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	Repair for other faults such as Out-
	as a result of another problem	put Speed Sensor Position Sensor.
		Look for other complaints such as
		engine brake or cruise not function-
		ing.
No button shifts after cruise con-	Hold Mode	Normal Operation. Lever must be
trol if turned off while in Top 2		cycled through neutral to regain but-
mode		ton function.
Harsh or aggressive splitter shifts	ECU Malfunction	Active Fault Code 11.		page 1
Before proceeding, see note at	Position Sensor Malfunction	Active Fault Code 36.		page 13
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	Lever/Splitter shifts attempted in an
	Engine Synchronous speed out-	out-of-synchronous condition. Re-
	of-limit of operating range	view Driver Instruction Book -
		TRDR-0580 - for proper driving
		techniques.
(Shifts from 1st to 2nd, 3rd. to 4	Low or high air pressure	Faulty Air Regulator.
th, 5th to 6th, 7 th to 8 th, and 9 th
to 10th. Shift grinds but engages.)
	Splitter leak or partial blocked air	Perform Splitter Cylinder Test.		page 26
	system
	Driver resting foot on Clutch	Remove foot from clutch pedal ex-
	Pedal so as to disengage clutch	cept when necessary to shift, start or
	switch but still has clutch en-	stop the vehicle.
	gaged

1-8

Fault Isolation Procedures

Symptom	Possible Condition	Remedy		Reference
	Clutch Switch Contamination	Cruise control and engine brake is
	built up on switch, for example,	also inoperative when the clutch
	dirt, ice, etc. or Mechanical	switch malfunctions. Refer to OEM
	Clutch Linkage	manual for	troubleshooting clutch
		switch.

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-
		synchronous condition. Review Driv-
					Fault
		er’s Instruction Book for proper tech-
		niques.
(Skip shifts. i.e. 1 st to 3 rd., or 3					Isolation
	Clutch Brake	Check for improper clutch brake en-
	Clutch Drag	Adjust Clutch and check for clutch
rd. to 5 th.)		slippage and drag.
		gagement.			Procedures
Slow/grinding/raking or inopera-	Low or High Air Pressure	Perform Range Cylinder Test.	page 22
tive Range Shift (Shift from 6 th to
7 th or from 7 th to 6 th.)
	Air System Leaks
	Reduced Air Flow
	Damaged Mechanical parts in-
	ternal to the transmission
Five speed transmission. (Only	ECU Malfunction	Active Fault Code 11.	page 1
Even or Odd Numbered Gears.)
	Unconfirmed torque path	Active Fault Code 66.	page 25
	through transmission
	Splitter stuck in gear	Active Fault Code 71.	page 29
		Review Air System Overview.	page 13
		Repair for damaged internal parts.
	Output Speed Sensor Malfunc-	Perform Output Shaft Speed Sensor	page 21
	tion	test.
	Splitter System Air Leak	Perform Splitter Cylinder test.	page 26
	Shift Knob Malfunction	No Active Fault Codes. Perform Shift	page 42
		Knob test.

1-9

Fault Isolation Procedures

Symptom	Possible Condition	Remedy	Reference
	Splitter Solenoid Short or Open	Active Fault Code 46. Perform Sole-	page 17
		noid test.
	Loss of communication with	Active Fault Code 35 and gears 1, 3, 5,	page 5
	engine	7, 9. J-1939 communication link bro-
		ken.
Six speed transmission. (Only 1st	Range system air leak	Perform Range Cylinder test.	page 22
through 6th gears.)
	Position sensor malfunction	Active Fault Code 36.	page 13
	Low Range Solenoid Malfunc-	Active Fault Code 43.	page 15
	tion
	High Range Solenoid Malfunc-	Active Fault Code 48.	page 19
	tion
	Range stuck in gear.	Active Fault Code 71.	page 29
	Transmission missed synchro-	Active Fault Code 73.	page 31
	nous.
	High Range Synchronizer Me-	Perform Range Cylinder test prior to	page 22
	chanical Failure	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.
Four Speed Transmission. (Only 7	Low Range Solenoid Malfunc-	Active Fault Code 43.	page 15
th through 10 th gears.)	tion
	Range System Air Leak	Perform Range Cylinder test.	page 22
	High Range Solenoid Malfunc-	Active Fault Code 48.	page 19
	tion
	Range stuck in gear.	Active Fault Code 71.	page 29
	Low Range Synchronizer Me-	Perform air system test prior to disas-
	chanical Failure	sembly, then replace damaged syn-
		chronizer 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.
Three Speed Transmission (Only	Low System Voltage	Active Fault Code 33.	page 3
1 st, 3 rd., 5 th gears)
	Loss of air pressure to trans-	Check vehicle air pressure.
	mission.
	ECU Malfunction.	Active Fault Code 11.	page 1
		Service light on continuously. Replace
		ECU.

1-10

Fault Isolation Procedures

Symptom	Possible Condition	Remedy	Reference
	Software download unsuccess-	Replace ECU.
	ful
Two Speed Transmission (only 7	ECU malfunction service light	Replace ECU.
th, 9 th gears)	on continuously
Neutral Switch	Wheel Chair Lift / PTO etc. not	Perform Neutral Switch Test per OEM
	operating	recommendations.
	Engine will not crank (some ap-	Perform Neutral Switch Test per OEM
	plications)	recommendations.
Reverse Switch	Reverse Light / Beeper not	Perform Reverse Switch Test per
	functioning.	OEM recommendations.

Procedures Isolation Fault

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	ECU
	sense desired range position

Range

H

L

S

Solenoid

Pak

	Charge Air
Splitter	Output Speed
	Sensor

Constant Air

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.

Procedures Isolation Fault

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

Range

HI Range Valve

Splitter

LO Range Valve

Splitter Valve

	To Splitter	Supply to	From Splitter Valve
80 PSI Supply	Cylinder
from Regulator /		Valves	To LO Range
Constant Air
to Splitter

Seal Plate

Range Cylinder

O-ring

Electronic Control Unit

(ECU)

Splitter Cylinder

O-rings

Exploded View of Air System

1-14

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	Constant Air Pressure

	Signal Air Pressure
Splitter in	Splitter in
Direct	Neutral
Constant Air Pressure

Signal Air Pressure

Splitter in

Overdrive

Procedures Isolation Fault

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	Air
	Pressure
		Pressure

Low Range

HI

R

LO

R

High Range

4 8

3 7

2	6	10
1	5	9
Low Range		High
		Range

1-16

Fault Isolation Procedures

Procedures Isolation Fault

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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.

Required Tools

•Basic Hand Tools

Possible Causes

Detection

Audible Air Leak

Fallback

•Splitter Cylinder O-Rings

•Range Cylinder O-Ring

•Air operated PTO leak

There is no fallback mode for this failure.

Possible Leak Paths

Splitter Cylinder

Range Cylinder

1-18

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						Air leaks in both positions
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	Air leaks only in low
	breather		may		be a		sign		range
	indicating			an	air		leak
	internal			to				the
	transmission.

Repair the splitter cylinder, and replace all cylinder o-rings. Go to Step V.

Repair the range cylinder, and replace all cylinder o-rings. Go to Step V.

Step V		Procedure		Condition		Action
	1. Fully	charge air		Breather still leaks		Go to Step A.
	system on vehicle and
	check	for
	effectiveness of repair.
				Breather does not leak		Test Complete.

Breather Housing Clutch

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

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

There is no fallback mode for failure.

Possible Leak Paths	Possible Leak Path

Splitter Cylinder

Range Cylinder

Solenoid

(Non-Serviceable - Inside ECU)

1-20

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			Leak stops with the		Replace the splitter cylinder o-
cylinder by moving the					button in the up position.		rings	and	clean	out	any
button	on	the	shift				contamination in the cylinder. If leak
knob from		the down					continues after making this repair,
position	to	the	up				then replace the transmission ECU
position.							and seal plate. Go to Step V.
					Leaks in either position		Go to Step B.

Step B	Procedure	Condition	Action

1.Key on, vehicle stationary and secured, air system fully charged, engine not running.

2. Cycle	the		range		Leak stops when in high		Replace the range cylinder piston
cylinder by moving the					range.		and clean out any contamination in
shift lever		into	high				the cylinder. If leak continues after
range	(the	7/8	gear				making this repair, then replace the
position) then back into							transmission ECU and seal plate.
neutral.			The				Go to Step V
synchronizer		makes a
distinct	audible		noise
when shifting.
					Leak stops when in low		Replace the range cylinder piston
					range.		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 V		Procedure		Condition		Action
	1. Charge the vehicle air			No Leaks		Test Complete
	system	and test
	repairs	for
	effectiveness.
				Air still leaks out breather		Repeat test procedures for air leaks.
				on ECU.

ECU Transmission

Leak Breather

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

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

There is no fallback for the Range Cylinder Test.

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 greater than 90 PSI and no leaks.

Repair vehicle's air system and go to Step V.

Go to Step B.

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

Air Inlet

Port

Transmission	filter/		Replace	filter/regulator
regulator pressure less			assembly. Go to Step V.
than or greater than 77 to
82 PSI.
Regulator	pressure		Go to Step C.

between 77 and 82 PSI.

Regulated

Air Pressure

Filter / Regulator

Test Cylinder Range

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		Go to Step D.
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					Remove transmission ECU	and
or the range shift is not					clean out any contamination in air
audible.					passages or cylinders. Go to	Step
					V.

Splitter Test Port

High Range Test Port

Low Range Test Port

Clean the area around the plugs prior to removal to prevent dirt or other contamination from falling into the ports after removing the plugs.

1-24

Fault Isolation Procedures

Range Cylinder Test, continued

Step D	Procedure	Condition	Action

1.Remove and disassemble transmission.

2. Inspect	all		Synchronizer		parts		Replace damaged parts. Go to Step
synchronizer parts.			excessively	worn	or		V.
			damaged.	Refer	to
			publication	TRSM-0915
			for	synchronizer
			replacement guidelines.
			No parts	worn	or		Go to Step V.
			damaged

Step V		Procedure		Condition		Action
	1. Start vehicle and road			Range shifts properly		Test complete
	test	to determine
	repair effectiveness.
				Range still grinds/rakes		Repeat test procedures
				or inoperative

Test Cylinder Range

1-25

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.

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.

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

•Faulty shift knob / splitter switch or vehicle wiring

•Internal mechanical failure

Fallback

There is no fallback for the Splitter Cylinder Test.

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		Driver	operating	splitter		Provide instruction and end test.
		operator.		improperly				Go to Step B.
				Driver	operating	splitter
				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.

3.Start vehicle and build up air pressure to maximum. Shut off vehicle.

Front of

Transmission

Air Inlet

Port

Transmission	filter/		Replace filter/regulator assembly.
regulator pressure less			Go to Step V.
than or greater than 77 to
82 PSI
Regulator	pressure		Go to Step D.

between 77 and 82 PSI

Regulated

Air Pressure

Filter / Regulator

Test Cylinder Splitter

1-27