Self Diagnostics System Check
The self diagnostic system check is an organized approach for identifying a problem caused by the on-car computer-controlled diagnostics.
NOTE:
The following step numbers refer to circled numbers on diagnostic charts. See Fig 1
and Fig 2
.
- This test assures that there are no BCM inputs active that would not allow the system to "wake-Up" in an incorrect sequence.
- If odometer displays a "0" or "ERROR", there could be a communication problem or component problem. See CHART A-1: DATA CIRCUIT PROBLEM .
- If the IPC or DIC is not lit, some characters may be faintly visible, but no backlighting exists to make characters stand out. If there is full backlighting with no characters, see CHART B-1 .
- Odometer appears normal.
- This checks the control of the ECM over the "ENGINE CONTROL SYSTEM FAULT" light.
- Odometer displays and "ENGINE CONTROL SYSTEM FAULT" light work. If diagnostics cannot be entered, see CHART C-1 .
- Refer to specific code charts for diagnosis. For diagnostic trouble code definitions, see DIAGNOSTIC TROUBLE CODE DEFINITIONS .