Component 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.
IMPORTANT:
You must perform the Circuit/System Testing in order to verify the integrity of the exhaust differential pressure sensor circuits before proceeding with Component Testing.
- Ignition OFF, remove the exhaust differential pressure sensor.
- Install a 3A fused jumper wire between the 5-volt reference circuit terminal 3 and the corresponding terminal of the differential sensor. Install a jumper wire between the low reference terminal 1 of the sensor and ground.
- Connect a DMM between terminal 2 of the differential sensor and ground.
- Ignition ON, with the J 23738-A
or J 35555
connected to the pressure sensor rear pressure port, slowly apply vacuum to the sensor while monitoring the voltage. See Special Tools
. The voltage should vary and transition smoothly without any spikes or dropouts.
- If the voltage is erratic, replace the differential sensor.