Check For Intermittent Problems

CHECK FOR INTERMITTENT PROBLEMS

HINT: Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect with an intelligent 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 2 trip detection logic.

1. Clear the DTCs.
2. Switch the ECM from normal mode to check mode using an intelligent tester.
3. Perform a simulation test.
4. Check and wiggle the harness(es), connector(s) and terminal(s).