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 1 trip detection logic, which is more sensitive to malfunctions than normal mode (default), which uses 2trip detection logic.

1. Clear DTCs (see DIAGNOSTIC TROUBLE CODES CHECK/CLEAR ).
2. Switch the ECM from normal mode to check mode using a hand-held tester (see CHECK MODE PROCEDURE ).
3. Perform a simulation test (see HOW TO PROCEED WITH TROUBLESHOOTING ).
4. Check and wiggle the harness (es), connector (s) and terminal (s) (see ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).