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.
- Verify the integrity of the entire air induction system by inspecting for the following conditions:
- Any damaged components
- Loose or improper installation
- An air flow restriction
- Any vacuum leaks
- Water intrusion
- In cold climates, inspect for any snow or ice buildup
- Ignition OFF, disconnect the MAF/IAT harness connector at the MAF/IAT sensor.
- Ignition OFF for 90 seconds, test for less than 5.0 ohms of resistance between the ground circuit terminal C and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal B and ground.
- If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
- Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal A and ground.
- If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
- If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- Connect the J 38522 to the vehicle. Refer to Component Testing for instructions.