GM Service Manual Online
For 1990-2009 cars only

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

  1. Perform the Diagnostic System Check - Vehicle , before using the Symptom Tables in order to verify that all of the following are true:
  2. • There are no DTCs set.
    • The control modules can communicate via the serial data link.
  3. Review the system operation in order to familiarize yourself with the system functions. Refer to the following:
  4. •  Audible Warnings Description and Operation
    •  Door Ajar Indicator Description and Operation
    •  Driver Information Center (DIC) Description and Operation
    •  Indicator/Warning Message Description and Operation
    •  Instrument Cluster Description and Operation
    •  Rear Hatch/Gate Ajar Indicator Description and Operation

Visual/Physical Inspection

    • Inspect for aftermarket devices which could affect the operation of the Instrument Cluster or Audible Warning Systems. Refer to Checking Aftermarket Accessories .
    • Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
    • Inspect the applicable reservoir for the proper fluid level related to the indicator or message.
    • Verify that the indicators work properly during the displays test.

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

Indicators

    •  Change Engine Oil Indicator Always On
    •  Door Ajar Indicator Malfunction
    •  Low Fuel Indicator Inoperative
    •  Mirror Compass Display Inoperative or Inaccurate
    •  Mirrors - Temperature Display Inaccurate
    •  Mirrors - Temperature Displays SC or OC
    •  Rear Hatch/Gate Ajar Indicator Malfunction
    •  Service Indicator Always On for the NVG 226-NP8 transfer case
    •  Service Indicator Inoperative for the NVG 226-NP8 transfer case
    •  Brake Warning Indicator Always On
    •  Brake Warning Indicator Inoperative
    •  ABS Indicator Always On
    •  ABS Indicator Inoperative
    •  Traction Off Indicator Always On
    •  Traction Off Indicator Inoperative
    •  Charge Indicator Always On
    •  Charge Indicator Inoperative
    •  Malfunction Indicator Lamp (MIL) Always On for the 4.2L engine
    •  Malfunction Indicator Lamp (MIL) Inoperative for the 4.2L engine
    •  Malfunction Indicator Lamp (MIL) Diagnosis for the 5.3L engine
    •  Malfunction Indicator Lamp (MIL) Diagnosis for the 6.0L engine
    •  Fog Lamp Indicator Inoperative
    •  Headlamp Switch On Indicator Always On
    •  Headlamp Switch On Indicator Inoperative
    •  High Beam Indicator Always On
    •  High Beam Indicator Inoperative
    •  Turn Signal Lamps and/or Indicators Always On or Flashing
    •  Turn Signal Lamps and/or Indicators Inoperative
    •  Air Bag Indicator Circuit Malfunction
    •  Seat Belt Indicator Circuit Malfunction
    •  Cruise Control Indicator Always On
    •  Cruise Control Indicator Inoperative
    •  Security Indicator Always On or Flashing
    •  Security Indicator Inoperative

Driver Information Center

Driver Information Center (DIC) Switch Inoperative

Instrument Cluster Dimming

    •  Interior Backlighting Does Not Dim
    •  Interior Backlighting Inoperative

Odometer

Odometer Trip/Reset Switch Inoperative

Audible Warning

    •  Chime Always On
    •  Chime Inoperative