Page 3241 of 5267

6.CHECK IF PRESSURE SWITCHES READ OPEN
In the DTC EVENT DATA recorded earlier,read the state of all pressure switches.
Do all the pressure switches read open?
Ye s>>
Go To 7
No>>
Go To 8
7.CHECK FOR LOW LINE PRESSURE
In the DTC EVENT DATA recorded earlier,compare the Line Pressure to 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 weal for a spit, crack , or improperly installed. If the filer 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>>
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.
8.CHECK IF IN PARK, NEUTRAL, OR REVERSE
Ignition on, engine not running.
With the scan tool, read and record the DTC EVENT DATA for P0871.
NOTE: Make sure to record all DTC EVENT DATA stored in the scan tool for future reference in this test
procedure.
Does the DTC EVENT DATA show the OD Pressure Switch DTC set while in Park, Neutral, or Reverse?
Ye s>>
Go To 18
No>>
Go To 9
9.CHECK IF THE OD PRESSURE SWITCH WAS OPEN
Refer to the DTC EVENT DATA recorded earlier for P0871.
Did the OD Pressure Switch read OPEN?
Ye s>>
Go To 10
No>>
Go To 15
10.CHECK FOR LOW LINE PRESSURE
Refer to the DTC EVENT DATA recorded earlier and 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 the fluid level. Check the Primary Oil Filter seal
for a split, crack, or improperly installed. Refer to the Service Information for the proper installation pro-
cedure. If the fluid level and filter are OK, check the Main Regulator Valvein the Oil Pump.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Go To 11
Page 3242 of 5267

11 .CHECK THE (T9) OD 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 (T9) OD 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 (T9) OD Pressure
Switch Sense circuit and any other circuit(s) in the Transmis-
sion Solenoid/TRS Assembly harness connector?
Ye s>>
Repair the (T9) OD 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>>
Go To 12
12.CHECK TO SEE IF THE DTC RESETS
Reconnect all previously disconnected connectors.
With the scan too, erase transmission DTCs.
Test drive the vehicle, use the DTC EVENT DATA recorded earlier to help duplicate the conditions when the DTC
originality set.
Does the DTC P0871 reset?
Ye s>>
Go To 13
No>>
Go To 22
13.CHECK THE POWERTRAIN CONTROL MODULE
Remove the Transmission Control Relay.
Operate the vehicle in Drive.
Is the transmission slipping while in Drive?
Ye s>>
Go To 14
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)
14.AIR CHECK TRANSMISSION CLUTCH OPERATION
Perform an Air Check Transmission Clutch Operation procedure per the Service Information.
Page 3243 of 5267

NOTE: The OD/Rev piston contains a small bleed orifice, a small amount of leakage between the OD and
Reverse hydraulic clutch circuits is considered normal.
Is there excessive air leakage in any clutch circuit?
Ye s>>
Check the OD/Rev piston seals and bleed orifice, reaction shaft support seal rings, dribbler orifice
assemblies in the reaction shaft support and for poor machine on the pump valve body faces. Refer to
the Service Information.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Repair the Valve Body. Check the OD Accumulator piston and seals, OD bleed orifice, and No.6 check
ball cuts or damage. If no problems are found in the Valve Body, replace the Transmission Solenoid/
TRS Assembly. Refer to the Service Information for proper repair procedures.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
15.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 Transmission Simulator, Miller tool #8333.
Ignition on, engine not running.
With the Transmission Simulator, turn the Pressure Switch selector switchtoOD.
With the scan tool, monitor the OD Pressure Switch state while pressing thePressure Switch Test button on the
Transmission Simulator.
Did the state of the OD Pressure Switch change from OPEN to CLOSED while pressing the Test but-
ton?
Ye s>>
Go To 16
No>>
Go To 18
16.CHECK IF THE NO. 4 AND/OR NO. 6 CHECK BALL IS CUT OR DAMAGED
With the scan tool, erase previously stored DTC’s and test drive the vehicle, use the DTC EVENT DATA to help
duplicate the conditions when the DTC originality set. Note any DTCs that may set.
Remove the Transmission Valve Body per the Service Information.
Check the No. 4 and No. 6 Check Balls for cuts or damage.
Is the No. 4 and/or No. 6 Check Ball cut or damaged?
Ye s>>
Replace the No. 4 and/or No. 6 Check Ball and check for clutch debris in the transmission oil pan. If
there is excessive debris, perform internal repairs to the OD Clutch Assembly. Refer to the Service Infor-
mation for proper repair procedures.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Go To 17
Page 3244 of 5267

17.CHECK THE TRANSMISSION SOLENOID/TRS ASSEMBLY
Did the DTC P0871 reset during the test drive in the previous step?
Ye s>>
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. (Refer to 21- TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)
No>>
Go To 22
18.CHECK THE (T9) OD PRESSURE SWITCH SENSE CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Disconnect the PCM C4 harness connector and connect Miller tool
#8815.
Disconnect the Transmission Solenoid /TRS Assembly harness connec-
tor
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install Miller tool #8815 to per-
form diagnosis.
Measure the resistance of the (T9) OD Pressure Switch Sense circuit
from the appropriate terminal of Miller tool #8815 to the Solenoid/TRS
Assembly harness connector.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the (T9) OD Pressure Switch Sense circuit for an
open.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PRO-
CEDURE)
No>>
Go To 19
Page 3245 of 5267

19.CHECK THE (T9) OD PRESSURE SWITCH SENSE CIRCUIT FOR A SHORT TO GROUND
Measure the resistance between ground and the (T9) OD Pressure
Switch Sense circuit.
Is the resistance below 5.0 ohms?
Ye s>>
Repair the (T9) OD Pressure Switch Sense circuit for a
short to ground.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION
TEST - VER 1. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PRO-
CEDURE)
No>>
Go To 20
20.CHECK WIRING AND CONNECTORS
Using the schematics as a guide, inspect the wiring and connectors. Pay particular attention to all power and ground
circuits.
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>>
Go To 21
21.CHECK THE POWERTRAIN CONTROL MODULE
Reconnect all previously disconnected connectors.
Make sure all DTC EVENT DATA is recorded.
With the scan tool, erase previously stored DTC’s and test drive the vehicle, use the DTC EVENT DATA to help
duplicate the conditions when the DTC originality set.
Does the DTC P0871 reset?
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>>
Go To 22
Page 3246 of 5267
22.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.
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 .
Page 3247 of 5267
P0875-UD HYDRAULIC PRESSURE TEST
For a complete wiring diagramRefer to Section 8W
Page 3248 of 5267

When Monitored:
In any forward gear with engine speed above 1000 RPM shortly after a shift and every minute thereafter.
Set Condition:
After a shift into a forward gear, with engine speed above 1000 RPM, the PCM momentarily turns on element
pressure to the Clutch circuits that don’t have pressure to identify the correct Pressure Switch closes. If the
Pressure Switch does not close 2 times, the DTC sets.
Possible Causes
LINE PRESSURE SENSOR
TRANSMISSION FLUID CONTAMINATION
RELATED DTC’S PRESENT
TRANSMISSION SOLENOID/TRS ASSEMBLY
EXCESSIVE DEBRIS IN OIL PAN
POOR LINE PRESSURE SENSOR CONNECTION
(T29) UD PRESSURE SWITCH SENSE CIRCUIT OPEN
TRANSMISSION CONTROL RELAY DTCS PRESENT
(T29) UD PRESSURE SWITCH SENSE CIRCUIT OPEN
(F856) 5-VOLT SUPPLY CIRCUIT OPEN
(T29) UD PRESSURE SWITCH SENSE CIRCUIT SHORT TO GROUND
(F856) 5-VOLT SUPPLY CIRCUIT SHORT TO GROUND
(T29) UD PRESSURE SWITCH SENSE CIRCUIT SHORT TO VOLTAGE
TRANSMISSION SOLENOID/TRS ASSEMBLY
INTERNAL TRANSMISSION
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 Control System tests the pressure switches when they areoff. The test verifies that the switches
are operational (They will close with pressure applied). The Transmission Control System verifies that the switch
closes when the corresponding element is applied. If a switch fails to close, it is re-tested. If it fails the second test,
the DTC will set, the MIL will illuminate and the transmission system will default to the orderly Shutdown routine.
Diagnostic Test
1.CHECK IF RELATED DTCS ARE PRESENT
With the scan tool, check for other transmission DTCs.
Is there any Loss of Prime, TCM Power Input Signal, and/or Line Pressure Sensor DTCs present?
Ye s>>
Refer to the Transmission category and perform the appropriate symptom. If the DTC, P0944-LOSS OF
PRIME is present, perform its respective test first.
No>>
Go To 2