11 .CHECK THE WIRING AND CONNECTORS
Turn the ignition off to the lock position.
Remove the Ignition Switch Feed fuse from the TIPM.
CAUTION: Removal of the Ignition Switch Feed fuse from the TIPM will prevent the vehicle from being
startedingear.
WARNING: The Ignition Switch Feed fuse must be removed from the TIPM. Failure to do so can result in
personal injury or death.
Remove the Line Pressure Adapter, Miller tool #8259 and 0-300 psi Test Gauge, Miller tool #C-3293-SP.
Install the Transmission Simulator, Miller tool #8333.
On the Transmission Simulator, turn the Pressure Switch selector switch to UD.
Ignition on, engine not running.
With the scan tool, monitor the UD Pressure Switch state while pressing andholding the Pressure Switch test but-
ton and wiggling the wire harness and connectors that pertain to the UD Pressure Switch.
Did the UD Pressure Switch state change to closed and remain closed while wiggling the wires?
Ye s>>
Go To 12
No>>
Go To 14
12.CHECK FOR EXCESSIVE DEBRIS
Turn the ignition off to the lock position.
Remove the Transmission Simulator, Miller tool #8333.
Remove and inspect the Transmission Oil Pan per the Service Information.
Does the Transmission Oil Pan contain excessive debris or contamination?
Ye s>>
Repair the cause of the excessive debris in the Transmission Oil Pan. Referto the Service Information
for the proper procedures.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Go To 13
13.CHECK THE UD HYDRAULIC CLUTCH CIRCUIT
Remove the Valve Body and air check the UD hydraulic clutch circuit (in the case) for leakage per the Service
Information.
NOTE: The UD hydraulic clutch circuit contains a small bleed orifice. A small amount of air leakage is nor-
mal.
Was there excessive air leakage noticed during the air check?
Ye s>>
Repair as necessary. Check the UD clutch piston, piston seals and bleed orifice, reaction shaft support
seal rings, and machining of the main mating faces of the pump housing, pumpvalve body, and reaction
shaft support.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Disassemble and inspect the Valve Body and repair as necessary. Inspect the UD Accumulator piston
and seals. If no problems are found in the Valve Body, replace the Transmission Solenoid/TRS Assem-
bly per the Service Information.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
16.CHECK THE (T29) UD PRESSURE SWITCH SENSE CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
Disconnect all PCM harness connectors.
Disconnect the Transmission Solenoid/TRS Assembly harness connec-
tor.
NOTE: Make sure the Transmission Solenoid/TRS Assembly har-
ness connector is disconnected.
Measure the resistance between the (T29) UD Pressure Switch Sense
circuit and all other circuits in the Transmission Solenoid/TRS Assembly
harness connector.
Is the resistance below 5.0 ohms between the (T29) UD Pres-
sure Switch Sense circuit and any other circuit(s) in the Trans-
mission Solenoid/TRS Assembly harness connector?
Ye s>>
Repair the (T29) UD Pressure Switch Sense circuit for a
short to another circuit(s).
Perform 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PRO-
CEDURE)
No>>
Using the schematics as a guide, check the Powertrain Control Module (PCM)terminals for corrosion,
damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems
are found, replace the PCM per the Service Information. With the scan tool,perform QUICK LEARN.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
17.INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specifictothiscircuit.
Wiggle the wires while checking for shorted and open circuits.
With the scan tool, check the DTC EVENT DATA to help identify the conditionsin which the DTC was set.
If the DTC EVENT DATA shows the DTC P0875 set while the Line Pressure was significantly below the Desired
Line Pressure reading, check for causes of low line pressure (low fluid level, broken or mis-installed primary oil filter
or filter seal, sticking Main Regulator Valve in the Pump Valve Body etc.).IfthedatashowstheDTCsetwhilethe
Line Pressure reading was significantly higher than the Desired Line Pressure, check the Line Pressure Sensor and
related wiring.
Where there any problems found?
Ye s>>
Repair as necessary.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
When Monitored:
Continuously with the ignition on and engine running.
Set Condition:
This DTC is set if the UD pressure switch is in the wrong state for the currentgear. For example, this code
would be set if the UD pressure switch remained off while the transmission was in second gear.
Possible Causes
RELATED TCM POWER INPUT DTCS PRESENT
LOW FLUID LEVEL
NO. 2 CHECK BALL CUT OR DAMAGED
LOW LINE PRESSURE
CRACKED OR MIS-INSTALLED SUMP FILTER OR SEAL
STICKING MAIN REGULATOR VALVE IN PUMP VALVE BODY
(T29) UD PRESSURE SWITCH SENSE CIRCUIT OPEN
(T29) UD PRESSURE SWITCH CIRCUIT SHORT TO GROUND
(T29) UD PRESSURE SWITCH SENSE CIRCUIT SHORT TO ANOTHER CIRCUITS
TRANSMISSION SOLENOID/TRS ASSEMBLY
POWERTRAIN CONTROL MODULE
Always perform the 45RFE/545RFE Pre-Diagnostic Troubleshooting Procedure before proceeding. (Refer to
21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
Theory of Operation
The Transmission system uses five pressure switches to monitor the fluid pressure in the LR, 2C, 4C, UD, and OD
clutch circuits. The pressure switches are continuously monitored for the correct states in each gear as shown.
GEAR L/R 2C 4C UD OD
REVERSEOPEN OPEN OPEN OPEN OPEN
P/NCLOSED** OPEN OPEN OPEN OPEN
1STCLOSED* OPEN OPEN CLOSED OPEN
2NDOPEN CLOSED OPEN CLOSED OPEN
2ND PRIMEOPEN OPEN CLOSED CLOSED OPEN
3RDOPEN OPEN OPEN CLOSED CLOSED
4THOPEN OPEN CLOSED OPEN CLOSED
5THOPEN CLOSED OPEN OPEN CLOSED
*L/R is closed if output speed is below 100 rpm in Drive and Manual 2. L/R is closed in Manual 1.
**May be open when rolling in Neutral or at low oil temperatures.
Diagnostic Test
1.CHECK IF RELATED DTCS ARE PRESENT
With the scan tool, check for other transmission DTC’s.
Are there any TCM Power Input Signal, Line Pressure, and/or Loss of Prime DTCs present?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom. If a Loss of Prime DTC is
present, perform its respective test first.
No>>
Go To 2
7.CHECK THE UD PRESSURE SWITCH STATUS
Refer to the DTC EVENT DATA recorded earlier.
Did the DTC P0876 set with the UD Pressure Switch closed?
Ye s>>
Go To 10
No>>
Go To 8
8.CHECK THE LINE PRESSURE
In the DTC EVENT DATA recorded earlier,compare the Line Pressure and the Desired Line Pressure.
Is the Line Pressure less than 40 psi, and significantly below the Desired Line Pressure?
Ye s>>
Repair as necessary to correct low line pressure. Check fluid level and adjustasnecessary.Iffluidlevel
is OK, check the Primary Oil Filter seal for a split, crack, or improperly installed. If the filter and seal are
OK, check the Main Regulator Valve in the Oil Pump. Refer to the Service Information for the above
procedures.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Go To 9
9.CHECK THE (T29) UD PRESSURE SWITCH SENSE CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
Turn the ignition off to the lock position.
Disconnect all PCM harness connectors.
Disconnect the Transmission Solenoid/TRS Assembly harness connec-
tor.
Measure the resistance between the (T29) UD Pressure Switch Sense
circuit and all other circuits in the Transmission Solenoid/TRS Assembly
harness connector.
Is the resistance below 5.0 ohms between the (T29) UD Pres-
sure Switch Sense circuit and any other circuit(s) in the Trans-
mission Solenoid/TRS Assembly harness connector?
Ye s>>
Repair the (T29) UD Pressure Switch Sense circuit for a
short to another circuit(s).
Perform 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PRO-
CEDURE)
No>>
Replace the Transmission Solenoid/TRS Assembly per the Service Information. (Refer to 21 - TRANS-
MISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE/TRANS SOLENOID/TRS ASSY -REMOVAL)
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1.
10.CHECK THE PCM AND WIRING
Turn the ignition off to the lock position.
Remove the Ignition Switch Feed fuse from the TIPM.
CAUTION: Removal of the Ignition Switch Feed fuse from the TIPM will prevent the vehicle from being
startedingear.
WARNING: The Ignition Switch Feed fuse must be removed from the TIPM. Failure to do so can result in
personal injury or death.
Install the Transmission Simulator, Miller tool #8333.
Ignition on, engine not running.
With the Transmission Simulator, turn the Pressure Switch selector switch to the UD position.
16.CHECK IF THE DTC RESETS
Reconnect all previously disconnected connectors.
With the scan tool, erase all transmission DTCs.
Test drive the vehicle. Using the DTC EVENT DATA recorded earlier, try to duplicate the conditions in which the
DTC originally set.
Does the DTC P0876 reset?
Ye s>>
Go To 17
No>>
Go To 18
17.CHECK FOR A CUT NO. 2 CHECK BALL
Remove the Valve Body per the Service Information.
Check the No. 2 check ball for cuts or damage.
Is the No. 2 check ball cut or damaged?
Ye s>>
Replace the No. 2 check ball. Check for excessive clutch debris in the oil pan. If excessive debris is
present, check the UD Clutch and repair as necessary.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Replace the Transmission Solenoid/TRS Assembly per the Service Information. Check for excessive
clutch debris in the oil pan. If excessive debris is present, check the UD Clutch and repair as necessary.
(Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE/TRANS SOLENOID/TRS
ASSY - REMOVAL)
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
18.CHECK FOR INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specifictothiscircuit.
Wiggle the wires while checking for shorted and open circuits.
With the scan tool, check the DTC EVENT DATA to help identify the conditionsin which the DTC was set.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
3.CHECK LINE PRESSURE CONNECTOR AND WIRING
Ignition on, engine not running.
With the scan tool, monitor the Line Pressure Sensor voltage while wiggling the wiring harness and connectors
pertaining to the Line Pressure Sensor and the Transmission Solenoid/TRSAssembly.
Did the voltage remain steady while wiggling the wiring harness and connectors?
Ye s>>
Go To 4
No>>
Disconnect and properly reconnect the Line Pressure Sensor connector. Inspect terminals and repair as
necessary.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
4.CHECK PCM AND WIRING
Turn the ignition off to the lock position.
Remove the Ignition Switch Feed fuse from the TIPM.
CAUTION: Removal of the Ignition Switch Feed fuse from the TIPM will prevent the vehicle from being
startedingear.
WARNING: The Ignition Switch Feed fuse must be removed from the TIPM. Failure to do so can result in
personal injury or death.
Install the Transmission Simulator, Miller tool #8333.
With the Transmission Simulator select the
OFFposition on theInput/Output Speedswitch.
Ignition on, engine not running.
With the scan tool, monitor the Line Pressure during the following step.
With the Transmission Simulator, turn the selector switch to each of the 3 Line Pressure positions.
NOTE: All three scan tool Line Pressure readings should be steady and ±14 kPa or 2.0 psi of the reading
specified on the Transmission Simulator.
Does the Line Pressure on the scan tool fluctuate up and down more than 69 kPaor 10 psi at any of
the 3 line pressure positions on the Transmission Simulator?
Ye s>>
Using the schematics as a guide, check the Powertrain Control Module (PCM)terminals for corrosion,
damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems
are found, replace the PCM per the Service Information. With the scan tool,perform QUICK LEARN.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Repair internal transmission and inspect the oil pump per the Service information and replace if neces-
sary. If no problems are found, replace the Transmission Solenoid/TRS Assembly — possible cause is
the Pressure Control Solenoid is stuck.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
5.CHECK WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specifictothiscircuit.
Wiggle the wires while checking for shorted and open circuits.
With the scan tool, check the DTC EVENT DATA to help identify the conditionsin which the DTC was set.
Where there any problems found?
Ye s>>
Repair as necessary.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
P0944-LOSS OF HYDRAULIC PUMP PRIME
For a complete wiring diagramRefer to Section 8W
When Monitored:
If the transmission is slipping in any forward gear and all the pressure switches are not indicating pressure, a
loss of prime test is run.
Set Condition:
If the transmission begins to slip in a forward gear and all the pressure switch(s) that should be closed are
open a loss of prime test begins. Available elements are turned on by the PCMto see if pump prime exists.
The DTC sets if no pressure switch(s) respond.
Possible Causes
SHIFT LEVER OUT OF ADJUSTMENT
IMPROPER FLUID LEVEL
CRACKED OR IMPROPERLY INSTALLED PRIMARY OIL FILTER OR SEAL
LOOSE COOLER RETURN FILTER
STUCK OR STICKING MAIN REGULATOR VALVE
TRANSMISSION OIL PUMP
Always perform the 45RFE/545RFE Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to
21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
Theory of Operation
The Loss of prime test is used to prevent transmission defaults and erroneous fault codes during temporary loss of
pump prime that may occur with low transmission fluid under severe brakingconditions, start-up, etc. and to point
towards more subtle problems such as a plugged or cracked oil filter.
The Loss of Prime DTC is set by a loss of hydraulic pressure in the transmission system. This condition, if sus-
tained, will result in the vehicle being unable to move.
Diagnostic Test
1.SHIFT LEVER POSITION TEST
Using the scan tool, perform a Shift Lever Position test. Follow the instructions on the scan tool.
Did the Shift Lever Position Test pass?
Ye s>>
Go To 2
No>>
Refer to the Transmission category and perform the appropriate symptom.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
2.CHECK TO SEE IF DTC P0944 IS CURRENT
Place the gear selector in Park.
Start the engine.
The transmission must be at operating temperature prior to checking pressure. A cold transmission will give higher
readings.
Run the engine at 1500 RPM.
With the scan tool, monitor the Transmission Line Pressure.
Does the Line Pressure match the Desired Line Pressure within ± 5 psi?
No>>
Go To 6
Ye s>>
Go To 3
3.CHECK LINE PRESSURE IN DRIVE AND REVERSE
Firmly apply the brake and repeat the previous test in both Drive and the Reverse gear positions.
With the scan tool, monitor the Transmission Line Pressure.
Does the Line Pressure match the Desired Line Pressure within ± 5 psi in all gear ranges?
Ye s>>
Go To 4
No>>
Go To 5
4.REVIEW CUSTOMER COMMENTS
The conditions necessary to set this DTC are not present at this time.
Verify with the customer if a delayed engagement and/or an intermittent
No Drivecondition has occurred.
If the customers answer is
Noerase the DTC and return the vehicle to the customer.
Make sure to check for any TSBs or controller flash updates that my apply.
With the scan tool, check the DTC EVENT DATA to help identify the conditionsin which the DTC was set.
Has the customer experienced any delayed engagement and/or
No Driveconditions?
Ye s>>
Repair internal transmission as necessary. Replace the Transmission OilPump if inspection reveals no
signs of internal seal leakage. Refer to the Service Information for the proper repair procedure.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
5.DTC VERIFICATION
Read and record the DTC and the DTC EVENT DATA information.
Test drive the vehicle and attempt to operate the vehicle within the parameters in which the DTC set.
With the scan tool, read DTCs.
Did any following DTCs set, P0868, P0944, P0841, P0846, P0871, P0876, or P0988?
Ye s>>
Go To 6
No>>
Te s t C o m p l e t e .
6.CHECK TRANSMISSION OIL FILTER
Remove and inspect the Transmission Oil Pan per the Service Information.
Remove and inspect the Primary Oil Filter per the Service Information.
Inspect the oil filter seal for damage and proper installation.
Does the Oil Pan contain excessive debris and/or is the Oil Filter plugged or seal damaged?
Ye s>>
Repair the cause of the plugged transmission oil filter or excessive debris. Check the Transmission Oil
Filter seal for improper installation onto filter neck instead of into thepump bore, not fully seated against
pump housing, filter neck not engaged into pump. Repair as necessary.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Repair the Transmission Oil Pump as necessary. Check for a stuck main regulator valve and clean if
necessary. Refer to the Service Information for the proper repair procedure.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)