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 2trip detection logic.

1. Clear DTCs (see DTC 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 ).