Diagnostic Test

• With the scan tool, read all ECU DTCs and record on the repair order.
• Check for DTCs in other modules that may cause a PCM related DTC to set.
• With the scan tool, run a Vehicle Scan Report and save the file for future use.
• Check the vehicle repair history for any recent repairs that may be related to the customer complaint.
• Verify that the Battery is fully charged and meets OEM specification.
• With the scan tool, verify that the Battery voltage to the PCM matches the actual Battery voltage of the vehicle.
• With a scan tool, check the PCM for software updates that are related to the DTC or customer complaint.
  • If a flash update is available, read the Service Bulletin to determine if the software update is applicable to the customer complaint before updating the module.
• Use the Search function in TechCONNECT to search for any related information under SERVICE ACTIONS/ TIPS.
  • Perform any Service Bulletins or other procedures that may apply.
• Check for aftermarket electrical accessories. Be certain they are installed properly and do not interfere with any related power, ground, or signal circuits. Be certain aftermarket wiring harnesses are routed away from vehicle wiring harness to avoid electromagnetic interference (EMI) where applicable.
• If necessary, check the vehicle build configuration and compare with the OEM Vehicle Build Configuration on TechCONNECT. Properly configure the vehicle if necessary.
• If multiple DTCs are set in the PCM, and no detectable pattern is evident (i.e. the DTCs are not related to just one or two components or subsystems), check the PCM ground circuits for proper continuity. As a general rule, diagnose the DTCs in the following order unless instructed to do so by the specific DTC procedure:
  1. ECU Configuration DTCs
  2. PCM High or Low Voltage DTCs
  3. PCM Internal Error DTCs
  4. Communication DTCs (See below)
  5. 5-Volt Sensor Reference High or Low DTCs
  6. Circuit Fault DTCs (Circuit Low, Circuit High, Open Circuit, etc.,)
  7. Performance / Rationality DTCs
  8. Other
• If multiple communication DTCs are set, diagnose the DTCs in the following order unless instructed to do so by the specific DTC procedure:
  1. CAN Bus Off
  2. CAN Bus Off Performance
  3. Lost Communication
  4. Implausible or Invalid Data
  5. Missing Message
  6. Other

Were any of the above conditions found?

Yes 

• Perform the appropriate repair procedure.
• Perform the POWERTRAIN VERIFICATION TEST. Refer to .

No 

• Perform the diagnostic test procedure related to the DTC. and perform the appropriate diagnostic procedure. Refer to .