Circuit/System Testing
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT:
Perform the Repair Verification after completing the Circuit/System Testing.
- Inspect the DOC for any of the following abnormal conditions:
- Physical damage or alterations
- Internal rattles caused by a damaged catalyst substrate
- Internal restrictions-Refer to Restricted Exhaust .
- If a condition is found, replace the DOC.
- Inspect the exhaust system for the following conditions:
- Restrictions-Refer to Restricted Exhaust .
- Exhaust leaks before DPF
- Physical damage or alterations
- If a condition is found, repair the exhaust system as necessary.
- Inspect for the following conditions, which may cause a DOC to degrade:
- An engine misfire-Refer to Fuel Injector Balance Test with Tech 2 .
- Engine oil or coolant consumption
- Leaking fuel injectors
- A fuel that does not meet the ultra low sulfur requirements, red dye fuel, or off road diesel fuel
- Contaminated fuel-Refer to Contaminants-in-Fuel Diagnosis .
- If a condition is found, repair as necessary, then replace the DOC.
- If all inspections and tests are normal, replace the DOC.