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Self-Diagnostic System Check

NOTE: Perform this check if one or more segments on the climate control panel or driver information center do not illuminate.

The Self-Diagnostic System Check is an organized approach for identifying a problem caused by the on-board computer controlled electronics. Understanding this chart and using it correctly will reduce diagnosis time and prevent the unnecessary replacement of parts.

NOTE: The following step numbers refer to circled numbers on diagnostic chart. See Fig 1 .
  1. This process assures that there are no BCM inputs active that would not allow the system to "Wake-Up" in the correct sequence. Are the IPC and COMBO Panel displays operating? If these displays are not operating, then the problem is related to power and ground circuits to the IPC, COMBO Panel, or BCM.
  2. Is the "Engine Control System Fault" telltale working? If this telltale fails to illuminate during crank, then the problem could be in the power supply circuits to the computer system.
  3. The odometer displays and "Engine Control System Fault" lamp work. Enter diagnostics and continue with code diagnosis. If diagnostics cannot be entered, refer to CHART C-1: VEHICLE WILL NOT ENTER DIAGNOSTICS  . Is there a trouble code displayed? If a trouble code is identified using the self-diagnostics, a problem has been detected by the system which can be corrected following the appropriately numbered code chart.
Fig 1: Self Diagnostic System Check Flow Chart
G00114122Courtesy of GENERAL MOTORS CORP.