Diagnostic Procedure

Using scan tool, check for transaxle-related DTCs. If DTC P0944 is also present, see DTC P0944: LOSS OF PRIME . If DTC P0944 is not present, go to next step.
Using scan tool, check for other transaxle-related DTCs. If DTCs P0888, P0890 or P0891 are also present, diagnose these DTCs first in order listed. If no other transaxle-related DTCs are present, go to next step.
Using scan tool, check STARTS SINCE SET counter for DTC P0841. If counter is set at 2 or less, go to next step. If counter is not set at 2 or less, go to step 11.

NOTE: Failure to remove starter relay can cause a NO RESPONSE FROM TCM condition.

Turn ignition off. Remove starter relay from power distribution center. See Figure. This prevents vehicle from starting in gear. Install Transmission Simulator (8333). Turn ignition on. Place pressure switch selector on simulator to L-R. Using scan tool, observe L-R pressure switch state while pressing pressure switch button. If switch state changes while pressing button, go to next step. If switch state did not change while pressing button, go to step 6.
If no other potential causes for DTC P0841 remain, L-R pressure switch in solenoid assembly is assumed to be faulty. Repair or replace solenoid assembly as necessary. See REMOVAL & INSTALLATION in appropriate SERVICING article in AUTOMATIC TRANSMISSIONS.
Turn ignition switch to LOCK position. Disconnect PCM harness connector C4 and solenoid assembly harness connectors. Measure resistance of L-R pressure switch sense circuit between solenoid assembly harness connector terminal No. 2 and PCM harness connector C4 terminal No. 29 using Miller Special Tool (8815). See WIRING DIAGRAMS . If resistance is greater than 5 ohms, repair open circuit. If resistance is 5 ohms or less, go to next step.
Measure resistance between ground and L-R pressure switch sense circuit at PCM harness connector C4 terminal No. 29 using Miller Special Tool (8815). If resistance is less than 5 ohms, repair circuit for short to ground. If resistance is 5 ohms or greater, go to next step.

NOTE: When testing circuits with a test light, ensure test light illuminates brightly. Compare test light brightness of circuits to brightness of test light when connected to direct battery voltage. If circuits do not illuminate with same brightness as direct battery voltage, circuit must be repaired.

Remove transmission control relay from power distribution center. See Figure. Using fused jumper wire, jumper fused B+ circuit and transmission control relay output circuit together at transmission control relay connector. See WIRING DIAGRAMS . Using test light connected to ground, probe transmission control relay output circuit at solenoid assembly harness connector terminal No. 4. If test light illuminates brightly, remove test light and go to next step. If test light does not illuminate brightly, repair open or high resistance in transmission control relay output circuit. If fuse is open, ensure to check for short to ground.
Leave fused jumper wire connected between fused B+ circuit and transmission control relay output circuit at transmission control relay connector. Turn ignition on. Measure voltage between ground and L-R pressure switch sense circuit at PCM harness connector C4 terminal No. 29 using Miller Special Tool (8815). If voltage is greater than .5 volt, repair circuit for short to voltage. If voltage is .5 volt or less, go to next step.
If no other potential causes for DTC P0841 remain, PCM is assumed to be faulty. Repair or replace as necessary. See POWERTRAIN CONTROL MODULE under REMOVAL & INSTALLATION.
Conditions necessary to set DTC are not present at this time. Using wiring diagram as a guide, inspect wiring and connectors associated with circuits in question. See WIRING DIAGRAMS . Wiggle wires while checking for shorted and open circuits. Repair as necessary. If circuits are okay, testing is complete.