Diagnostic Strategies
MULTIPORT FUEL INJECTION (MFI) SYSTEM INSPECTIONIf the MFI system components (sensors, ECM, injector, etc.) fail, interruption or failure to supply the proper amount of fuel for various engine operating conditions will result. The following situations may be encountered.
1. Engine is hard to start or does not start at all.
2. Unstable idle
3. Poor driveability
If any of the above conditions is noted, first perform an inspection by self-diagnosis and subsequent basic engine checks (ignition system malfunction, incorrect engine adjustment, etc.), and then inspect the individual MFI system components.
SELF-DIAGNOSIS
1. Check for diagnostic trouble codes (DTC)s stored in the control module memory.
2. Read the output diagnostic trouble codes (DTC)s.
3. Identify the output DTCs in Trouble Code Descriptions and perform the appropriate component/circuit tests for the items listed in the "Component" column of the chart.
Diagnostic Trouble Code Descriptions
4. Erase the diagnostic trouble code(s).
TSB-TECHNICAL SERVICE BULLETINS
Check for TSBs that may be related to a vehicle symptom, component test or diagnostic trouble code (DTC). TSBs may contain additional information that can provide help with vehicle diagnosis.