Diagnostic Procedures

Perform POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK . Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. After performing OBD system check, go to next step.
Turn ignition on, engine off. Place gear selector in Park. Using scan tool, read TR PABC display. If scan tool displays P=O A=O B=X C=X, go to next step. If display is not as specified, go to step 4).

Observe scan tool display while placing gear selector in each gear position. Record TR PABC status for each gear position. Compare scan tool display for each gear position with TRANSAXLE RANGE SWITCH VALID INPUT COMBINATIONS table. If scan tool display matches table entries for each gear selected, see DIAGNOSTIC AIDS. If scan tool display does not match table entries, go to step 10).

TRANSAXLE RANGE SWITCH VALID INPUT COMBINATIONS

Gear Selector Position	Scan Tool TR PABC Display
Park	P=O A=O B=X C=X
Reverse	P=X A=O B=O C=X
Neutral	P=O A=X B=O C=X
Drive 4	P=X A=X B=O C=O
Drive 3	P=O A=O B=O C=O
Drive 2	P=X A=O B=X C=O
Drive 1	P=O A=X B=X C=O

If scan tool displays P=X A=X B=X C=X, go to next step. If display is not as specified, go to step 7).
Check if TRS 4-pin harness connector is disconnected or damaged. Repair as necessary. After repairs, go to step 17). If no problem is found, go to next step.
Check for open in TRS 7-pin harness connector ground circuit. Repair as necessary. After repairs, go to step 17). If circuit is okay, go to step 13).
If scan tool displays P=O A=O B=O C=O, go to next step. If display is not as specified, return to step 3).
Disconnect TRS 4-pin harness connector. If scan tool displays P=O A=O B=O C=O, go to next step. If display is not as specified, go to step 14).
Turn ignition off. Disconnect PCM. Check TRS input circuit for being pinched or shorted to ground. Repair as necessary. After repairs, go to step 17). If no problem is found, go to step 16).
Ensure wires in TRS 4-pin harness connector are not crossed. Repair as necessary. After repairs, go to step 17). If no problem is found, go to next step.
Turn ignition off. Disconnect PCM and TRS. Turn ignition on. Check for open, short to ground or short to voltage in circuit which caused incorrect TRS input combination. Repair as necessary. After repairs, go to step 17). If no problem is found, go to next step.
Reconnect TRS. Connect a test light between battery voltage and TRS circuit which caused incorrect TRS input combination at PCM. Observe and record state of test light while selecting each gear position. Compare state of test light in each gear position with TRANSAXLE RANGE SWITCH VALID INPUT COMBINATIONS table. If test light illuminates when input state should be "O" and off when input state should equal "X", go to step 15). If test light illuminates as specified, go to next step.
Check for faulty connection at TRS 4-pin and 7-pin connectors. Repair as necessary. After repairs, go to step 17). If no problem is found, go to next step.
Replace TRS. After replacing switch, go to step 17).
Check for faulty connection at PCM. Repair as necessary. After repairs, go to step 17). If no problem is found, go to next step.
Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
Clear DTCs. Observe scan tool display while placing gear selector in each gear position. Record TR PABC status for each gear position. Compare scan tool display for each gear position with TRANSAXLE RANGE SWITCH VALID INPUT COMBINATIONS table. If scan tool display matches table entries for each gear selected, repair is complete. If scan tool display does not match table entries, return to step 2).