Diagnostic Procedures
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2002 GMC Sonoma, 2002 GMC Safari, 2002 GMC Jimmy, 2002 Chevrolet S10 Pickup, and 2002 Chevrolet Blazer. However, it is still accessible from the selected car via links, so may be relevant.
- Did you perform the Diagnostic System Check-Engine Controls? If yes, go to next step. If no, see DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM.
- Are any other DTCs set? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, go to next step.
- Inspect for the following conditions:
- Verify that the three-way catalytic converter (TWC) is an original equipment part.
- Inspect the TWC for damage, such as dents, severe discoloration caused by excessive temperature, holes, etc.
- Ensure that the internal TWC rattle caused by damaged catalyst is not present.
- Inspect the exhaust system for leaks, damage, or loose or missing hardware, in area from converter to HO2S 2 primarily.
- Ensure that the HO2S 1 and the HO2S 2 are secure and that the pigtails and wiring are not damaged or contacting the exhaust.
Repair conditions, as necessary. Did you find and correct the condition? If yes, go to step 5. If no, go to next step.
- Replace the catalytic converter. After repairs, go to next step.
- Select the Diagnostic Trouble Code (DTC) option and the Clear DTC Information option using the scan tool. Idle the engine at the normal operating temperature. Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool. Operate the vehicle within the Conditions for Running DTC, if applicable. Does the scan tool indicate that this test ran and passed? If yes, go to next step. If no, go to step 2.
- Observe the stored information, Capture Info with a scan tool. Does the scan tool display any DTCs that you have not diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.