Troubleshooting Flow, Strategy and Guidelines

DIAGNOSTIC STRATEGIES

If 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 can 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 Reading Diagnostic Trouble Codes and subsequent basic engine checks (ignition system malfunction, incorrect engine adjustment, etc.), and then inspect the MFI system components with the Scan Tool (ST).

NOTE:
1) Before removing or installing any part, read the diagnosis code and then disconnect the battery negative (-) terminal.
2) Before disconnecting the cable from battery terminal,turn the ignition switch to OFF. Removal or connection of battery cable during engine operation or while the ignition switch is ON could cause damage to the ECM.
3) The control harnesses between the ECM and oxygen sensor are shielded wires with the shield grounded to the body in order to prevent the influence of ignition noises and radio intolerance. When the shielded wire is faulty the control harness must be replaced.