Using On-Board Diagnostics

Turn ignition on (engine off). Press RESET button on Driver Information Center (DIC) to acknowledge any warning messages that may be present. See Fig 1. Press OPTIONS button and hold. While holding OPTIONS button, press FUEL button 4 times within 10 seconds. System will enter automatic display mode.

In automatic display mode, each system module will be displayed on DIC followed by DTCs that exist in that module. If no DTCs exist, DIC will display NO CODES. If DTCs exist, each DTC will be displayed for 3 seconds followed by a one second pause. If Instrument Panel Cluster (IPC) cannot communicate with any system, DIC will display NO COMM for that system. At any time during automatic display mode, manual display feature can be activated by pressing any DIC button except E/M button. When all systems have been checked in automatic mode, DIC will display NO MORE CODES for 2 seconds, and will then enter manual mode.

When manual mode is entered, DIC will display MANUAL DIAGNOSTICS for 2 seconds or until any DIC button except E/M button is pressed. DIC will then display first system and number of DTCs set in that system, and wait for further instructions. Using DIC buttons, move through system diagnostics as necessary. See DIC BUTTON DIAGNOSTIC FUNCTIONS  table. See Fig 1. Note all codes displayed in Body Control Module (BCM) and proceed to appropriate diagnostic and repair procedure. See BODY CONTROL MODULE DIAGNOSTIC TROUBLE CODE DEFINITIONS  table.

When E/M button on DIC is pressed at any time, IPC will exit diagnostics mode. On-board diagnostics will also be exited automatically if no DIC buttons are pressed for 60 seconds.

Fig 1: Identifying Driver's Information Center (DIC) Buttons

Courtesy of GENERAL MOTORS CORP.