Diagnostic System Check

Diagnostic System Check - Engine Cooling

Steps 1-4:

Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. Lack of communication may be due to a malfunction of the class 2 or GMLAN serial data circuits. The specified procedure will determine the particular condition.
4. The presence of DTCs which begin with U indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.