Troubleshooting Strategy

NOTE: If a DTC is erased, its "freeze frame" data will also be erased and the readiness test status will be reset. Store the "freeze frame" data before erasing the DTC.

Use these steps to plan your diagnostic strategy. If you follow them carefully, you will be sure to have exhausted most of the possible ways to find an MFI fault.

Gather as much information as possible about the complaint from the customer.
Verify that the condition described by the customer exists.
Check the vehicle for any MFI Diagnostic Trouble Codes (DTCs), refer to RETRIEVING & CLEARING DIAGNOSTIC TROUBLE CODES .
If you cannot verify the condition and there are no DTCs, the malfunction is intermittent. For information on how to cope with intermittent malfunctions, refer to INTERMITTENT FAILURES .
If you can verify the condition but there are no DTCs, or the system cannot communicate with the scan tool, proceed to the TROUBLE SHOOTING - NO CODES article.
If there is a DTC, record the number of the code, then erase the code from the memory using the scan tool.
Reconfirm the malfunction symptom and carry out a test drive with the drive cycle pattern, refer to DRIVE CYCLES .
If DTC is set again, carry out the appropriate inspection procedure under DIAGNOSTIC TESTS . For a complete list of diagnostic trouble codes, refer to DIAGNOSTIC TROUBLE CODE DEFINITIONS .
If DTC is not set again, the malfunction is intermittent. For information on how to cope with intermittent malfunctions, refer to INTERMITTENT FAILURES .
After repairs are completed, conduct a road test duplicating the complaint set conditions to confirm the malfunction has been corrected.

NOTE: If the Engine Control Module (ECM - M/T) or Powertrain Control Module (PCM - A/T) is replaced, Immobilizer Encrypted Code Registration should be carried out. See appropriate ANTI-THEFT SYSTEMS article.