Test Description

The numbers below refer to the step numbers in the diagnostic procedure.

• Step 4.) Lack of communication may be because of 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.
• Step 5.) The symptom list in Symptoms will determine the correct diagnostic procedure to use. See SYMPTOM INDEX  table under SYSTEM TESTS.
• Step 6.) The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will collect all the available information before you perform tests.