Circuit/System Testing
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Verify the integrity of the entire exhaust system by visually inspecting for the following conditions:
- Any damaged components
- Improper installation. The exhaust differential pressure lines should have a continuous downward gradient, without bends or kinks, from the differential pressure sensor to the particulate filter.
- Improperly routed exhaust differential pressure sensor lines. The smaller line connects to the front of the exhaust particulate filter and the smaller port of the exhaust pressure sensor.
- Remove the exhaust differential pressure sensor lines. Visually inspect the lines for restrictions.
- If a condition is found, replace the exhaust differential pressure lines.
- Verify the integrity of the entire air induction system by inspecting for the following conditions:
- Restrictions in the air induction system and the turbocharger system
- Leaks in the intake air ducts and the turbocharger ducts
- Cracked or damaged MAF sensor housing
- Inspect for a dirty air filter element
- Debris blocking the air sensing filaments of the MAF sensor
- If a condition is found, repair as necessary.
- Test the charge air cooler system for leaks. Perform the Full System Air Leak Test in Charge Air Cooler Diagnosis (Full System Air Leak Test)
or Charge Air Cooler Diagnosis (Induction System Smoke Test)
or Charge Air Cooler Diagnosis (Charge Air Cooler Air Leak Test)
.
- If a charge air cooler leak is found, repair as necessary.
- Test the engine air induction system for leaks. Perform the Induction System Smoke Test in Charge Air Cooler Diagnosis (Full System Air Leak Test)
or Charge Air Cooler Diagnosis (Induction System Smoke Test)
or Charge Air Cooler Diagnosis (Charge Air Cooler Air Leak Test)
.
- If an induction air leak is found, repair as necessary.
- If the air intake system, exhaust system, DPF components, and the charge air cooler test normal, replace the particulate filter.
IMPORTANT:
Perform the Repair Verification after completing the Circuit/System Testing.