Diagnostic Test

1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. With the scan tool, run a vehicle Scan Report, or record the Environmental Data related to the DTCs.
3. With the scan tool, erase all DTCs.
4. Turn the ignition off for a minimum of 10.0 seconds.
5. Turn the ignition on.
6. Using the recorded Environmental Data and the When Monitored Conditions above, operate the vehicle in the conditions that set the DTC.
7. With the scan tool, read DTCs.

Did the DTC return?

Yes 

• Go To  2

No 

• Go To  6

1. Turn the ignition off.
2. Disconnect the ESM harness connector.
3. Turn the ignition on.
4. Measure the voltage between ground and the CAN DPT (+) circuit at the ESM harness connector.
5. Measure the voltage between ground and the CAN DPT (-) circuit at the ESM harness connector.

   Is the voltage between 2.4 and 2.6 volts for each circuit?

   Yes 

   • Using the schematics as a guide, check the ESM terminals for corrosion, damage or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the ESM in accordance to the Service Information. Refer to MODULE, ELECTRONIC SHIFT (ESM), REMOVAL AND INSTALLATION .
   • Perform the ESM VERIFICATION TEST. Refer to ELECTRONIC SHIFT MODULE (ESM) VERIFICATION TEST .

   No 

   • Go To  3

1. Turn the ignition off.
2. Disconnect the Transmission Control Module (TCM) harness connector.
3. Measure the resistance of the CAN DPT (+) circuit between the ESM harness connector and the TCM harness connector.
4. Measure the resistance of the CAN DPT (-) circuit between the ESM harness connector and the TCM harness connector.

   Is the resistance below 3.0 Ohms for each circuit?

   Yes 

   • Go To  4

   No 

   • Repair the affected CAN DPT circuit(s) for an open or high resistance.
   • Perform the ESM VERIFICATION TEST. Refer to ELECTRONIC SHIFT MODULE (ESM) VERIFICATION TEST .

1. Check for continuity between ground and the CAN DPT (+) circuit at the TCM harness connector.
2. Check for continuity between ground and the CAN DPT (-) circuit at the TCM harness connector.

   Is there continuity between ground and the either of the CAN DPT circuits?

   Yes 

   • Repair the affected CAN DPT circuit(s) for a short to ground.
   • Perform the ESM VERIFICATION TEST. Refer to ELECTRONIC SHIFT MODULE (ESM) VERIFICATION TEST .

   No 

   • Go To  5

1. Check for continuity between the CAN DPT (+) circuit and all other circuits at the TCM harness connector.
2. Check for continuity between the CAN DPT (-) circuit and all other circuits at the TCM harness connector.

   Is there continuity between either CAN DPT circuit and any other circuit?

   Yes 

   • Repair the affected CAN DPT circuit(s) for a short to another circuit.
   • Perform the ESM VERIFICATION TEST. Refer to ELECTRONIC SHIFT MODULE (ESM) VERIFICATION TEST .

   No 

   • Using the schematics as a guide, check the ESM terminals for corrosion, damage or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the ESM in accordance to the Service Information. Refer to MODULE, ELECTRONIC SHIFT (ESM), REMOVAL AND INSTALLATION .
   • Perform the ESM VERIFICATION TEST. Refer to ELECTRONIC SHIFT MODULE (ESM) VERIFICATION TEST .

1. The conditions necessary to set the DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
3. Wiggle the wires while checking for shorted and open circuits.
4. Check for any Service Bulletins that may apply.

   Were any problems found?

   Yes 

   • Repair as necessary.
   • Perform the ESM VERIFICATION TEST. Refer to ELECTRONIC SHIFT MODULE (ESM) VERIFICATION TEST .

   No 

   • Perform the ESM VERIFICATION TEST. Refer to ELECTRONIC SHIFT MODULE (ESM) VERIFICATION TEST .
   • Test complete.