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Instrument Panel Cluster Diagnostic Information

Subject:Instrument Panel Cluster Diagnostic Information

Models:2003-2005 Chevrolet Kodiak C4500-C8500 Series
2003-2005 GMC Topkick C4500-C8500 Series


The purpose of this bulletin is to provide information relative to diagnosing and correcting the following Instrument Panel Cluster (IPC) concerns:

   • 

Unresponsive Cluster

   • 

"P" in PRNDL Legend not operating properly

   • 

No Gauge Pointer Movement and PRNDL/Odometer Display Dim

   • 

Airbag Telltale Remains ON After Bulb Check

   • 

Loss of Class 2 Communication

Important:  BEFORE DIAGNOSING ANY CONCERN WITH AN IPC, BE SURE THAT THE CLUSTER HAS BEEN PROGRAMMED WITH THE CORRECT CALIBRATIONS FOR THE VEHICLE. ALL CLUSTERS MUST BE PROGRAMMED USING TIS 2000 AFTER THEY ARE INSTALLED IN THE VEHICLE.

Unresponsive Cluster:

Symptoms:

With the ignition switch in the Accessory, Run or Crank position, the following concerns may be noted:

    • Gauges remain at LOW position with no evidence of motion
    • No odometer/PRNDL display illumination
    • Most or all telltales are inoperative

Possible Causes:

This concern may be caused by an issue with the DCL-08 Class2 Transceiver within the cluster. The DCL-08 chip has been replaced in the new cluster design.

Recommended Action:

  1. Disconnect the negative battery cable(s) for 10 seconds.
  2. Reconnect the negative battery cable(s) and turn the Ignition Switch ON.
    3. • If the cluster operates normally, replace the cluster with a 2005 model year cluster to prevent future concerns.
    • If the concern is still present, refer to "Cluster Inoperative" in the "IPC Gauges and Console" section of Service Information (SI).

"P" in PRNDL Legend Not Operating Properly:

Some of the Allison® Automatic Transmissions have a park position and some do not. LCT 1000, LCT 2200, LCT 2400 have a park position, the other transmissions do not. Before diagnosing a concern with the "P" not illuminating, be sure that the transmission has a park position. If the transmission has a park position and the "P" in the PRNDL does not illuminate, refer to "Park/Neutral Back-Up Switch Adjustment" in SI.

If the "P" in the PRNDL display illuminates and the transmission does not have a park position, the cluster will have to be replaced to turn off the indicator.

Important:  The Park/Neutral Back-Up Switch must be adjusted properly before replacing the cluster. If this is not done and the switch is out of adjustment, the new cluster will illuminate the "P" in the PRNDL when it is installed. If this occurs, the new cluster will have to be replaced.

No Gauge Pointer Movement and PRNDL/Odometer Display Dimmed

Symptoms:

With the ignition key switch in the RUN position:

    • The gauge pointers are positioned at mid-scale and there is NO movement.
    • The PRNDL/Odometer display is fully dimmed.
    • The telltales are functioning normally.

Possible Cause/Solution:

This concern is an indication that the cluster has not been programmed after installation.

Recommended Action:

Program the cluster with the correct calibrations for the vehicle.

Airbag Telltale Remains ON After Bulb Check:

Symptom:

With the ignition switch in the RUN position, the airbag telltale remains illuminated after the 3 second IPC bulb check is completed.

If the cluster has not been replaced, refer to Diagnostic System Check -- SIR in SI to diagnose the concern.

If the cluster has just been replaced, determine if the truck is equipped with a driver side airbag.

Without Driver Side Airbag:

Possible Causes:

  1. The cluster has not been programmed after installation
  2. The cluster has been programmed with the wrong calibration. Confirm that the correct VIN and cluster part number was used to select the calibration in TIS 2000.

Recommended Action:

Program the cluster with the correct calibration for the vehicle using TIS 2000.

With Driver Side Airbag:

Possible Causes:

  1. The cluster has not been programmed after installation.
  2. Cluster Synchronization has not been performed and a B1001 code has set.

Recommended Action:

  1. Program the cluster with the correct calibration for the vehicle using TIS 2000.
  2. Perform cluster synchronization as directed by following the B1001 code flow chart.

Loss of Class2 Communication:

Symptoms:

With the ignition switch in the RUN position, most or all of the following will be noted:

    • Minor gauges remain at ZERO position after initial synchronization - Speedometer, Tachometer, and Odometer may function normally.
    • The airbag, battery, brakes and ABS telltales remain illuminated after the 3 second IPC bulb check is completed.
    • No PRNDL position illuminated to indicate the gear state.

Possible Causes:

These symptoms are indicative of a loss of Class2 communication. The Speedometer, Tachometer and Odometer are controlled by discrete inputs and are independent of the Class2 link.

Recommended Action:

Check for Class2 or J1939 Data communication fault codes in other modules (SDGM, ECM, ABS, etc). If any are found, follow diagnostic service procedures in SI for the codes found.

Refer to Corporate Bulletin Number 03-08-49-019A for information on SDGM Programming.