Envoy 4WD V8-5.3L VIN P (2004)
Steps 5-6
The numbers below refer to the step numbers on the diagnostic table.
2. Lack of communication may be due to a malfunction in the class 2 serial data circuit. The specified procedure will determine the particular
condition.
5. The presence of DTCs which begin with "U" indicates that some other module is not communicating. The specified procedure will compile all the
available information before tests are performed.