Chart A-1 Data Circuit Problem (Digital Cluster)

You have been directed to this chart from the "Diagnostic System Check" as a result of an odometer reading of "0" or "Error". This is a result of total loss of communication on circuit 800 due to a wiring or element problem, or an EEPROM problem.

Notes on trouble trees
1. The ALDL cover is one of the branches of the 800 circuit, if it is off one should start diagnosis at "Self-Diagnostic System Check".
2. This step will isolate a fault in the data circuit between the ALDL cover and the programmer. If the odometer continues to read zero miles, circuits 800A, 800B, 800C, 800D, the Instrument Panel Cluster (IPC), BCM, and Computer Control Driver Information Center (CCDIC) are suspect.
3. This step will remove the problem if it is within the CCDIC or circuit 800A.
4. This will isolate circuit 800D as the problem, if the actual mileage returns.
5. This checks for a faulty IPC, or circuit 800C.
6. This final step will isolate the condition to the BCM, circuit 800C, or 800B.