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, engine running, with the transmission in gear.Set Condition:The DTC is set if the 2C Pressure Switch reads open or closed at the wrong time in a given gear .Possible CausesRELATED TIPM TCM DTCS PRESENT(T147) 2C PRESSURE SWITCH SENSE CIRCUIT OPEN(T147) 2C PRESSURE SWITCH SENSE CIRCUIT SHORT TO GROUND(T147) 2C PRESSURE SWITCH SENSE CIRCUIT SHORT TO OTHER CIRCUITSEXCESSIVE FLUID LEAKAGE IN 2C CLUTCH CIRCUITNO. 5 AND/OR NO. 7 CHECK BALL CUT OR DAMAGEDEXTRA CHECK BALL DOWNSTREAM OF THE NO. 7 CHECK BALL SOCKETLOW LINE PRESSURETRANSMISSION SOLENOID/TRS ASSEMBLYPOWERTRAIN CONTROL MODULEWIRING AND CONNECTORSAlways 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 FOR TCM TIPM DTCSWith the scan tool read DTCs.Are there any TIPM TCM Power Control Circuit or TCM Power Input DTCs present?YesRefer to the Transmission category and perform the appropriate symptom. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - DIAGNOSIS AND TESTING) NoGo To 22. CHECK IF THE DTC DATA SHOWS THE CURRENT DTCWith the scan tool, check the DTC EVENT DATA.Does the DTC EVENT DATA show data for DTC P0846?YesGo To 3NoRefer to the Transmission category and perform the appropriate symptom shown in the DTC EVENT DATA.Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) 3. CHECK IF MULTIPLE DTCS ARE PRESENTWith the scan tool, check DTCs.Are there two or more related pressure switch rationality DTCs present in addition to P0846?YesGo To 4NoGo To 74. CHECK IF ALL THE PRESSURE SWITCHES READ CLOSEDWith the scan tool, check the DTC EVENT DATA for P0846.Make sure to record all DTC EVENT DATA stored in the scan tool for future reference in this test procedure.Do all the pressure switches read CLOSED in the DTC EVENT DATA for P0846?YesRefer to Transmission category and perform diagnostics for P0882.NoGo To 55. CHECK IF ALL THE PRESSURE SWITCHES READ OPENIn the DTC EVENT DATA recorded earlier, read the state of all pressure switches.Do all the pressure switches read OPEN?YesGo To 6NoGo To 76. 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 fluid level and adjust as necessary. If fluid level 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. (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) 7. CHECK IF THE DTC SET IN PARK, NEUTRAL, OR REVERSEWith the scan tool, check the DTC EVENT DATA for P0846. 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 P0846 set in Park, Neutral, or Reverse?YesGo To 12NoGo To 88. CHECK IF THE 2C PRESSURE SWITCH READS CLOSEDWith the scan tool, check the DTC EVENT DATA for P0846.Does the DTC EVENT DATA show the 2C Pressure Switch reading CLOSED?YesGo To 10NoGo To 99. CHECK THE 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 fluid level and adjust as necessary. If fluid level 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. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) NoGo To 1510. 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.With the Transmission Simulator, turn the Pressure Switch selector switch to the 2C position.With the scan tool, monitor the 2C Pressure Switch while pressing the Pressure Switch test button on the Transmission Simulator.Did the state of the 2C Pressure Switch change while pressing the Pressure Switch Test button?YesGo To 11NoGo To 1211. CHECK THE TRANSMISSION SOLENOID/TRS ASSEMBLYUsing the schematics as a guide, inspect the wiring and connectors specific to this circuit.Wiggle the wires while checking for shorted and open circuits.Where there any problems found?YesRepair as necessary.Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST.NoReplace the Transmission Solenoid/TRS Assembly per the Service Information.Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) 12. CHECK THE (T147) 2C PRESSURE SWITCH SENSE CIRCUIT FOR AN OPEN

Turn the ignition off to the lock position.Disconnect the Transmission Simulator, Miller tool #8333.Disconnect the PCM C4 harness connector. Connect Miller tool #8815 to the PCM C4 harness connector.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 (T147) 2C Pressure Switch Sense circuit between the Transmission Solenoid/TRS Assembly harness connect and the appropriate terminal of Miller tool #8815.Is the resistance above 5.0 ohms?YesRepair the (T147) 2C 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 1313. CHECK THE (T147) 2C PRESSURE SWITCH SENSE CIRCUIT FOR A SHORT TO GROUND

Measure the resistance between ground and the (T147) 2C Pressure Switch Sense circuit.Is the resistance below 5.0 ohms?YesRepair the (T147) 2C 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 1414. CHECK THE (T147) 2C PRESSURE SWITCH SENSE CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT

Measure the resistance between the (T147) 2C Pressure Switch Sense circuit and all the other circuits in the Transmission Solenoid/TRS Assembly harness connector.Is the resistance below 5.0 ohms?YesRepair the (T147) 2C 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) NoUsing 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) 15. CHECK IF THE #5 AND/OR #7 CHECK BALL IS CUT OR DAMAGEDTurn the Ignition off to the lock position.Remove the Valve Body Assembly per the Service Information.Inspect the #5 and #7 check balls for any cuts or damage.Check for an extra check ball in the passage downstream from the #7 check ball pocket.Inspect the 2C accumulator piston and seals and also the 2C tower seal on top of the valve body. Refer to the Service Information.Where there any problems found?YesRepair as necessary. Check for excessive clutch debris in the transmission oil pan. If excessive clutch debris is present, repair 2C clutch as necessary. 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 1616. CHECK FOR EXCESSIVE FLUID LEAKAGE WITHIN THE 2C CLUTCH CIRCUITAir check the 2C Clutch hydraulic circuit. Refer to the Service Information.This hydraulic clutch circuit contains a small bleed orifice. Small leakage is considered normal.Was there excessive air leakage in the 2C Clutch hydraulic circuit?YesRepair as necessary. Refer to the Service Information.Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST.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)