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 MAF sensor circuits before proceeding with the Component Testing.
- Ignition OFF, remove the MAP sensor.
- Install a 3A fused jumper wire between the 5-volt reference terminal C and the corresponding terminal of the MAP sensor
- Install a jumper wire between the low reference terminal A of the MAP sensor and ground.
- Install a jumper wire at the signal terminal B of the MAP sensor.
- Connect a DMM between the jumper wire from terminal B of the MAP sensor and ground.
- Ignition ON, with the J 23738-A
or J 35555
, slowly apply vacuum to the sensor while observing the voltage on the DMM. See Special Tools
. The voltage should vary between 4.9-0.02 volts, without any spikes or dropouts.
- If the voltage is erratic, replace the MAP sensor.