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 Diagnostic System Check - Vehicle in order to verify the following conditions:
  2. • There are not any DTCs set.
    • The control modules can communicate via the serial data link.
  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
    •  Audible Warnings Description and Operation

Visual/Physical Inspection

    • Inspect for aftermarket devices which can affect the operation of the instrument panel cluster 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 and Odometer

    •  Instrument Cluster Inoperative
    •  Engine Oil Pressure Gage Inaccurate or Inoperative
    •  Change Engine Oil Indicator Malfunction
    •  Fuel Gage Inaccurate or Inoperative
    •  Hourmeter Inaccurate or Inoperative
    •  Instrument Cluster Gages Inoperative
    •  Speedometer and/or Odometer Inaccurate or Inoperative
    •  Tachometer Inaccurate or Inoperative
    •  Transmission Fluid Temperature Gage Inaccurate or Inoperative

Indicators

    •  ABS Indicator Malfunction
    •  Air Bag Indicator Circuit Malfunction
    •  Brake Warning Indicator Malfunction
    •  Charge Indicator Malfunction
    •  Diesel Particulate Filter Warning Indicator Malfunction
    •  Differential Lock Indicator Inoperative
    •  Low Engine Coolant Indicator Always On
    •  Low Traction Indicator Malfunction
    •  Low Washer Fluid Indicator Malfunction
    •  Malfunction Indicator Lamp (MIL) Diagnosis for the 6.6L engine
    •  Malfunction Indicator Lamp (MIL) Diagnosis for the 7.8L engine
    •  Malfunction Indicator Lamp (MIL) Diagnosis for the 8.1L engine
    •  Power Take-Off (PTO) Indicator Inoperative
    •  Power Take-Off (PTO) Description and Operation
    •  Service Brake Soon Indicator Malfunction
    •  Traction Off Indicator Malfunction
    •  Transfer Case Shift Control Switch Indicator Always On - Two or More
    •  Transfer Case Shift Control Switch Indicator Flashes, then Returns to Previous Mode
    •  Transfer Case Shift Control Switch Indicator Inoperative - One or More
    •  Turn Signal Lamps and/or Indicators Malfunction
    •  Water-in-Fuel Lamp Always On
    •  Water-in-Fuel Lamp Inoperative

Audible Warnings

Chime Malfunction