Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 2. Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
2. 4. The presence of DTCs which begin with a "U" indicate some other module is not communicating on the class 2 serial data circuit. The specified procedure will compile all the available information before tests are performed.
   Fig 1: Diagnostic System Check - Instrument Cluster

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