GM Service Manual Online
For 1990-2009 cars only

Important: The following steps must be completed before using the symptom diagnostic tables.

  1. Before using the symptom diagnostic tables, perform the following tests in order to determine that there are no DTCs set, and that the control modules can communicate via the serial data link:
  2. •  Diagnostic Starting Point - Vehicle
    •  Diagnostic System Check - Vehicle
  3. Review the system operation in order to understand the system functions. Refer to the following description and operations:
  4. •  Instrument Cluster Description and Operation
    •  Indicator/Warning Message Description and Operation
    •  Driver Information Center (DIC) Description and Operation
    •  Head Up Display (HUD) Description and Operation
    •  Audible Warnings Description and Operation

Visual/Physical Inspection

    • Inspect for aftermarket devices which can affect the operation of the instrument panel cluster (IPC) or the audible warnings system. Refer to Checking Aftermarket Accessories .
    • Inspect the accessible system components or the visible system components for obvious damage or for obvious conditions which can cause the symptom.
    • Inspect for the proper fluid levels.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

Gages

    •  Engine Oil Pressure Gage Inaccurate or Inoperative
    •  Fuel Gage Inaccurate or Inoperative
    •  Speedometer and/or Odometer Inaccurate or Inoperative
    •  Tachometer Inaccurate or Inoperative

Indicators

    •  ABS Indicator Always On
    •  ABS Indicator Inoperative
    •  Air Bag Indicator Circuit Malfunction
    •  Brake Warning Indicator Always On
    •  Brake Warning Indicator Inoperative
    •  Engine Oil Pressure Gage Inaccurate or Inoperative
    •  Engine Oil Temperature Indicator Always On
    •  Fog Lamp Indicator Always On
    •  Fog Lamp Indicator Inoperative
    •  High Beam Indicator Always On
    •  High Beam Indicator Inoperative
    •  Low Engine Oil Level Indicator Always On
    •  Low Engine Oil Level Indicator Inoperative
    •  Malfunction Indicator Lamp (MIL) Inoperative for the 6.0L engine
    •  Malfunction Indicator Lamp (MIL) Always On for the 6.0L engine
    •  Malfunction Indicator Lamp (MIL) Inoperative for the 7.0L engine
    •  Malfunction Indicator Lamp (MIL) Always On for the 7.0L engine
    •  Seat Belt Indicator Circuit Malfunction
    •  Security Indicator Inoperative
    •  Traction Control Indicator Always On
    •  Traction Control Indicator Inoperative
    •  Traction Off Indicator Always On
    •  Traction Off Indicator Inoperative
    •  Turn Signal Lamps and/or Indicators Always On or Flashing
    •  Turn Signal Lamps and/or Indicators Inoperative

Driver Information Center

Driver Information Center (DIC) Switch Inoperative

HUD

    •  Head Up Display (HUD) Always On
    •  Head Up Display (HUD) Inoperative
    •  Head Up Display (HUD) Image Adjustment Inoperative
    •  Head Up Display (HUD) Intensity Does Not Vary

Audible Warnings

    •  Chime Always On
    •  Chime Inoperative