Check For Intermittent Problems

HINT:

Hand-held tester only:

Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect with a hand-held tester when the ECM is in check mode. In check mode, the ECM uses 1trip detection logic, which is more sensitive to malfunctions than normal mode (default), which uses 2 trip detection logic.

1. (d) Clear DTCs (see DTC CHECK / CLEAR  ).
2. (e) Switch the ECM from normal mode to check mode using a hand-held tester (see CHECK MODE PROCEDURE  ).
3. (f) Perform a simulation test (see HOW TO PROCEED WITH TROUBLESHOOTING ).
4. (g) Check and wiggle the harness(es), connector(s) and terminal(s) (see HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).