GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The instrument cluster diagnostic system check is an organized approach to identify problems associated with the instrument cluster. This check must be the starting point for any instrument cluster complaint and will direct to you to the next logical step in diagnosing the complaint. The instrument cluster is a very reliable component and is not likely to be the cause of the malfunction. Most system complaints are linked to faulty wiring and connectors and occasionally to components. Understanding the instrument cluster system and using the diagnostic tables correctly will reduce diagnostic time and prevent unnecessary parts replacement.

Diagnostic Aids

    • The following conditions may result in an intermittent operation of the instrument cluster with no Diagnostic Trouble Code (DTC) stored:
       - Any condition which results in the interruption of power to the instrument cluster.
       - Out of range battery or ignition voltage specification. Normal battery or ignition voltage specification: 9-16V.
       - A loose or damaged ground(s).
       - An open or short in the Class II serial data link.
    • An intermittent failure in the electronic system may be very difficult to detect and accurately diagnose. The instrument cluster tests for different malfunctions under different vehicle conditions. For this reason a through test drive is often needed in order to repeat a fault condition. If the system malfunction is not repeated during the test drive, a good description of the complaint may be very useful in locating an intermittent fault condition. Faulty electrical connections or wiring cause most intermittent problems. When an intermittent condition is suspected check the suspected circuits for the following conditions:
       - Poor mating of connector halves or backed out terminals.
       - Improperly formed or damage terminals.
       - Wire chafing.
       - Poor wire-to terminal connections.
       - Dirty or corroded terminals.
       - Damage to connector bodies.
    • Use the J 35616-A kit whenever a diagnostic procedure requests probing or checking a terminal. Using this adapter will ensure that not damage to the terminal will occur and will give an idea of whether contact tension is sufficient. If the DTC is a history DTC, the problem may be intermittent. Perform the tests shown while moving related wiring and connectors. This can often cause the malfunction to occur. Perform a through inspection of all related wiring and connectors pertaining to the history DTC stored.
    • Exit all scan tool tests before cycling the ignition switch from the off to the on position unless the scan too instructions direct otherwise. Follow the operating instructions in the scan tool user's manual. Failure to follow these instructions may set DTCs, cause vehicle system malfunctions, set false DTCs or cause scan tool malfunctions.
    • Check all relative fuses for the instrument cluster. Refer to Instrument Cluster: Analog Schematics
    • Make sure all relative grounds are clean and tight. Refer to Instrument Cluster: Analog Schematics
    • For instrument cluster removal and replacement procedures, refer to Instrument Cluster Replacement
    • Check for a broken (or partially broken) wire inside of the insulation which could cause system malfunction but prove good in a continuity/voltage check with a system disconnected. These circuits may be intermittent or resistive when loaded and if possible should be checked by monitoring for a voltage drop with the system operational (under load).
    • Check for proper installation of after market electronic equipment which may affect the integrity of other systems.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This test determines if communication can be established with the instrument cluster.

  2. This test checks for stored instrument cluster DTCs.

  3. This test determines whether communication can be established with other vehicle systems connected to the Class II serial data link.

  4. This test checks the instrument cluster power circuits.

  5. This test checks for the instrument cluster ground circuits.

  6. This test determines if an open is present in the Class II serial data link.

Step

Action

Value(s)

Yes

No

1

  1. Turn the ignition switch off.
  2. Connect scan tool to the Data Link Connector (DLC).
  3. Turn the ignition switch on.
  4. Using scan tool, attempt to establish communications with the instrument cluster.

Does the scan tool communicate with the instrument cluster?

--

Go to Step 2

Go to Step 3

2

  1. Select display instrument cluster Diagnostic Trouble Codes (DTCs) function with the scan tool.
  2. Check for instrument cluster DTCs. Refer to Diagnostic Trouble Code (DTC) Displaying for more information.

Are any instrument cluster DTCs stored?

--

Go to Diagnostic Trouble Code (DTC) List/Type

Go to Step 11

3

Using scan tool, attempt to establish communications with other vehicle systems, such as the Powertrain Control Module (PCM) and the Body Control Module (BCM).

Does the scan tool communicate with the PCM and BCM?

--

Go to Step 4

Go to Data Link Communications System Check in Wiring Systems

4

  1. Turn the ignition switch off.
  2. Disconnect the instrument cluster connector.
  3. Turn the ignition switch on.
  4. Using a test light, frontprobe between each instrument cluster power circuit and ground by using a J 35616A kit.

Does the test light illuminate for all circuits?

--

Go to Step 5

Go to Step 8

5

Using a test light, frontprobe between each instrument cluster ground circuit and B+ by using a J 35616A kit.

Does the test light illuminate for all circuits?

--

Go to Step 6

Go to Step 9

6

  1. Turn the ignition switch off.
  2. Disconnect scan tool from DLC.
  3. Using a DMM, measure for continuity in circuit 1036/1132 between the instrument cluster harness connector terminal B1 and the data link connector terminal 2.

Is there continuity in circuits 1036/1132?

--

Go to Step 7

Go to Step 10

7

Service the instrument cluster. Refer to Instrument Cluster Replacement for service procedure.

Is the repair complete?

--

Go to Step 33

--

8

Repair poor connection or open in the instrument cluster power circuit.

Is the repair complete?

--

Go to Step 33

--

9

Repair poor connection or open in the instrument cluster ground circuit.

Is the repair complete?

--

Go to Step 33

--

10

Repair poor connection or open in circuit 1036/1132 between the data link connector terminal 2 and the instrument cluster harness connector B1.

Is the repair complete?

--

Go to Step 33

--

11

Does the ANTI-LOCK, LOW TRAC, TRAC LOCK, or LOW TIRE PRESSURE indicators remain illuminated or flash after the engine is started or when the car is driven?

--

Go to A Diagnostic System Check - ABS in Antilock Brake System

Go to Step 12

12

Does the CHANGE OIL, charge, coolant temp, LOW OIL, low oil pressure or SERVICE ENGINE SOON indicator remain illuminated or flash after the engine is started or when the car is driven?

--

Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls

Go to Step 13

13

Does the automatic transaxle control position indicator illumination operate properly when the transaxle shift selector has changed positions?

--

Go to Step 14

Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls

14

Does the air bag indicator remain illuminated or flash after the engine is started or when the car is driven?

--

Go to SIR Diagnostic System Check in SIR

Go to Step 15

15

Does the SECURITY indicator remain illuminated or flash after the engine is started or when the car is driven?

--

Go to Diagnostic System Check - Theft Deterrent in Theft Deterrent System

Go to Step 16

16

Is the high beam indicator inoperative or remain illuminated after the engine is started or when the car is driven?

--

Go to Headlight System Check in Lighting Systems

Go to Step 17

17

Are the turn signal indicators inoperative or remain illuminated after the engine is started or when the car is driven?

--

Go to Exterior Lights System Check in Lighting Systems

Go to Step 18

18

Is the CRUISE indicator inoperative or remain illuminated after the engine is started or when the car is driven?

--

Go to Cruise Control System Check in Cruise Control

Go to Step 19

19

  1. Fasten the driver's seat belt.
  2. While observing the seat belt indicator, turn the ignition switch on.
  3. While observing the seat belt indicator, unfasten the driver's seat belt.

Is the seat belt indicator inoperative or remain illuminated after the engine is started or when the car is driven?

--

Go to Audible Warnings System Check

Go to Step 20

20

Is the BRAKE warning indicator inoperative during bulb test?

--

Go to Brake Warning Indicator Inoperative in Hydraulic Brakes

Go to Step 21

21

Will the park brake activate the BRAKE warning indicator?

--

Go to Step 22

Go to Brake Warning Indicator Inoperative in Hydraulic Brakes

22

Is the BRAKE warning indicator inoperative with a low brake fluid condition?

--

Go to Brake Warning Indicator Inoperative in Hydraulic Brakes

Go to Step 23

23

Is the BRAKE warning indicator inoperative with an ABS malfunction detected?

--

Go to Brake Warning Indicator Inoperative in Hydraulic Brakes

Go to Step 24

24

Is the BRAKE warning indicator always on?

--

Go to Brake Warning Indicator Always On in Hydraulic Brakes

Go to Step 25

25

Is the low coolant indicator inoperative or remain illuminated after the engine is started or when the car is driven?

--

Go to Low Engine Coolant Indicator Inoperative

Go to Step 26

26

Is the LOW WASHER FLUID indicator inoperative or remain illuminated after the engine is started or when the car is driven?

--

Go to Low Fluid Level Indicator Inoperative

Go to Step 27

27

Is the SERVICE ENGINE SOON indicator inoperative or remain illuminated after the engine is started or when the car is driven?

--

Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls

Go to Step 28

28

Is the tachometer inoperative or function erratically after the engine is started or when the car is driven?

--

Go to Tachometer Inoperative

Go to Step 29

29

Is the speedometer/odometer inoperative or function erratically after the engine is started or when the car is driven?

--

Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls

Go to Step 30

30

Is the temperature Gauge inoperative or function erratically after the engine is started or when the car is driven?

--

Go to Engine Coolant Temperature Gage Inaccurate or Inoperative

Go to Step 31

31

Is the fuel gauge or the low fuel indicator inoperative or remain illuminated after the engine is started or when the car is driven?

--

Go to Fuel Gage Inaccurate or Inoperative

Go to Step 32

32

Does the instrument cluster illumination dim properly using the I/P lamp dimmer switch with the ignition switch in the on position?

--

Go to Step 33

Go to Interior Lights Dimming System Check in Lighting Systems

33

  1. Turn the ignition switch off.
  2. Reconnect connectors/components removed.
  3. Connect scan tool to the DLC.
  4. Turn the ignition switch on.
  5. Using scan tool, clear DTCs in the instrument cluster. Refer to Clearing DTCs for more information.
  6. Using scan tool, check for DTCs stored in the instrument cluster. Refer to Diagnostic Trouble Code (DTC) Displaying for more information.

Are there any DTCs stored in the instrument cluster?

--

Go to Diagnostic Trouble Code (DTC) List/Type

System OK