For a complete wiring diagram Refer to Section 8WThe Transmission system uses five pressure switches to monitor the fluid pressure in the L/R, 2C, 4C, UD, and OD clutch circuits. The pressure switches are continuously monitored for the correct states in each gear as shown.When Monitored:Continuously with the ignition on and engine running.Set Condition:The DTC will set if the L/R Pressure Switch reads open or closed at the wrong time in a given gear.Possible CausesLOSS OF PRIME AND/OR TIPM DTC PRESENTLOW FLUID LEVELLOW LINE PRESSUREREVERSE CARRIER SNAP RING DISLODGEDCRACKED OR MIS-INSTALLED PRIMARY OIL FILTER OR FILTER SEALSTICKING MAIN REGULATOR VALVE IN PUMP VALVE BODYNO. 1 CHECK BALL CUT OR DAMAGEDWIRING AND CONNECTORS(T50) L/R PRESSURE SWITCH SENSE CIRCUIT OPEN(T50) L/R PRESSURE SWITCH SENSE CIRCUIT SHORT TO GROUND(T50) L/R PRESSURE SWITCH SENSE CIRCUIT SHORT TO VOLTAGETRANSMISSION SOLENOID/TRS ASSEMBLYPOWERTRAIN CONTROL MODULEAlways perform the 45RFE/545RFE Pre-Diagnostic Troubleshooting Procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) GEARL/R2C4CUDODREVERSEOPENOPENOPENOPENOPENP/NCLOSED**OPENOPENOPENOPEN1STCLOSED*OPENOPENCLOSEDOPEN2NDOPENCLOSEDOPENCLOSEDOPEN2nd PRIMEOPENOPENCLOSEDCLOSEDOPEN3THOPENOPENOPENCLOSEDCLOSED4THOPENOPENCLOSEDOPENCLOSED5THOPENCLOSEDOPENOPENCLOSED*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.1. CHECK IF OTHER RELATED DTCS PRESENTIgnition on, engine not running.With the scan tool, check for other transmission DTCs.Are there any Loss of Prime, TCM Power Input, and/or TIPM TCM Power Control Circuit DTCs present?YesRefer to the Transmission category and perform the appropriate symptom. If the DTC P0944 is present, perform its respective test first.NoGo To 22. CHECK IF THE CONDITION P0841 IS PRESENTWith the scan tool, check the DTC EVENT DATA for P0841.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 DTC P0841?YesGo To 3NoRefer to the Transmission category and perform diagnostics for the DTC reported in the DTC EVENT DATA.3. CHECK IF THE DTC SET IN REVERSEDoes the DTC EVENT DATA show the DTC P0841 set while in Reverse?YesGo To 10NoGo To 44. CHECK IF THE L/R PRESSURE SWITCH IS CLOSEDDoes the DTC EVENT DATA show the L/R Pressure Switch reading CLOSED when the DTC P0841 was set?YesGo To 5NoGo To 145. CHECK THE PCM AND WIRINGTurn the ignition off to the lock position.Remove the Ignition Switch Feed fuse from the TIPM.Removal of the Ignition Switch Feed fuse from the TIPM will prevent the vehicle from being started in gear. 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.Turn the Pressure Switch selector to L/R on the Transmission Simulator.With the scan tool, monitor the L/R Pressure Switch state while pressing the Pressure Switch Test button on the Transmission Simulator.Did the L/R Pressure Switch state change from open to closed while pressing the Pressure Switch Test button on the Transmission Simulator?YesGo To 6NoGo To 106. CHECK FOR POOR WIRING AND CONNECTIONSUsing the schematics as a guide, inspect the wiring and connectors specific to this circuit.Wiggle the wires while checking for shorted and open circuits.Were there any problems found?YesRepair as necessary.Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) NoGo To 77. CHECK IF THE DTC SET IN FIRST GEARWith the DTC EVENT DATA recorded earlier, check what gear the transmission was in when the DTC P0841 was set.Does the DTC EVENT DATA show the Present Gear as first gear when the DTC P0841 was set ?YesGo To 8NoReplace the Transmission Solenoid/TRS Assembly per the Service Information. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE/TRANS SOLENOID/TRS ASSY - REMOVAL)Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) 8. CHECK IF THE NO. 1 CHECK BALL IS CUT OR DAMAGEDTurn the ignition off to the lock position.Remove the Transmission Valve Body per the Service Information.Check the No. 1 Check Ball for any possible cuts or damage.Is the No. 1 Check Ball cut or damaged?YesReplace the No. 1 Check Ball and check for clutch debris in the transmission oil pan. If there is excessive debris, perform internal repairs to the L/R Clutch assembly. Refer to the Service Information for proper repair procedures.Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) NoGo To 99. CHECK IF THE REVERSE CARRIER SNAP RING IS DISLODGED AND THE TRANSMISSION SOLENOID/TRS ASSEMBLYLooking through the windows in the bottom of the case, check whether the snap ring at the front of the Reverse (center) Carrier has dislodged.It may be necessary to pry the Input Annulus Gear Shell rearward to check this snap ring.Is the Reverse Carrier Snap Ring dislodged?YesRepair as necessary.Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) NoReplace the Transmission Solenoid/TRS Assembly per the Service Information. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE/TRANS SOLENOID/TRS ASSY - REMOVAL)Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) 10. CHECK THE (T50) L/R PRESSURE SWITCH SENSE CIRCUIT FOR AN OPEN

Turn the ignition off to the lock position.Disconnect the Transmission Simulator, Miller tool #8333 if connected in a previous step or disconnect the Transmission Solenoid/TRS Assembly harness connector.Disconnect the PCM C4 harness connector and connect Miller tool #8815.Check connectors - Clean/repair as necessary.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 perform diagnosis.Measure the resistance of the (T50) L/R Pressure Switch Sense circuit between the Solenoid/TRS Assembly harness connector and the appropriate terminal of the Miller tool #8815.Is the resistance above 5.0 ohms?YesRepair the (T50) L/R Pressure Switch Sense circuit for an open.Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) NoGo To 1111. CHECK THE (T50) L/R PRESSURE SWITCH SENSE CIRCUIT FOR A SHORT TO GROUND

Measure the resistance between ground and the (T50) L/R Pressure Switch Sense circuit.Is the resistance below 5.0 ohms?YesRepair the (T50) L/R Pressure Switch Sense circuit for a short to ground.Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) NoGo To 1212. CHECK THE PCM POWERS AND GROUNDSUsing 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.Were there any problems found?YesRepair as necessary.Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) NoGo To 1313. ROAD TEST THE VEHICLEWith the scan tool, clear the DTC and road test the vehicle.Try to duplicate the conditions in which the DTC originally set using the DTC EVENT DATA recorded earlier.Did the DTC P0841 reset?YesUsing 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. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) NoGo To 1714. CHECK FOR LOW LINE PRESSUREIn 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?YesRepair as necessary to correct low line pressure. Check for low fluid level. Check the Primary Oil Filter seal for a split, crack, or improperly installed. Refer to the Service Information for the proper installation procedure. If the fluid level and Primary Oil Filter are OK, check the Main Regulator Valve in the Oil Pump per the Service Information.Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) NoGo To 1515. CHECK THE (T50) L/R PRESSURE SWITCH SENSE CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT

Turn the ignition off to the lock position.Disconnect the Transmission Solenoid/TRS Assembly harness connector.Disconnect all PCM harness connectors.Measure the resistance between the (T50) L/R 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 (T50) L/R Pressure Switch Sense circuit and any other circuit(s) in the Transmission Solenoid/TRS Assembly harness connector?YesRepair the (T50) L/R Pressure Switch Sense circuit for a short to another circuit(s).Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) NoGo To 1616. ROAD TEST THE VEHICLEWith the scan tool, clear the DTC and road test the vehicle.Try to duplicate the conditions in which the DTC originally set using the DTC EVENT DATA recorded earlier.Did the DTC P0841 reset?YesReplace the Transmission Solenoid/TRS Assembly per the Service Information. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE/TRANS SOLENOID/TRS ASSY - REMOVAL)Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) NoGo To 1717. INTERMITTENT WIRING AND CONNECTORSThe conditions necessary to set this DTC are not present at this time.Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.Wiggle the wires while checking for shorted and open circuits.With the scan tool, check the DTC EVENT DATA to help identify the conditions in which the DTC was set.Were there any problems found?YesRepair as necessary.Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) NoTest Complete.