For 1990-2009 cars only
Diagnostic Starting Point - SIR for GMC Truck TopKick C-Series (Conventional) C4/C5 2004
Begin the system diagnosis with the Diagnostic System Check - SIR . The Diagnostic System Check - SIR will provide the following information:
| • | The identification of the control modules which commands the system |
| • | The ability of the control modules to communicate through the serial data circuit |
| • | The identification of any stored diagnostic trouble codes (DTCs) and their status |
The use of the Diagnostic System Check - SIR will identify the correct procedure for diagnosing the system and where the procedure is located.
