Check For Intermittent Problems

By putting the vehicle's ECM in check mode, 1 trip detection logic is possible instead of 2 trip detection logic and sensitivity to detect open circuits is increased. This makes it easier to detect intermittent problems.

CLEAR DIAGNOSTIC TROUBLE CODES.
(See Clearing Trouble Codes)
Clearing Diagnostic Trouble Codes

SET CHECK MODE.
(See Displaying and Reading Trouble Codes)
Reading Diagnostic Trouble Codes


PERFORM A SIMULATION TEST.







Using the symptom simulation, shake and pull lightly on the wire harness, connector or terminals in the circuit indicated by the malfunction code. In this test, if the MIL lights up, it indicates that the place where the wire harness, connector or terminals being pulled or shaken has faulty contact. Check that point for loose connections, dirt on the terminals, poor fit or other problems and repair as necessary.

HINT: After cancelling out the diagnostic trouble code in memory and setting the check mode, if the MIL does not go off after the engine is started, check thoroughly for faulty contacts, etc., then try the check again. If the MIL still does not go off, check and replace the ECM.