Component Testing
WARNING: This page is about a different car, the 2010 Pontiac G5 and 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
You must perform the Circuit/System Testing in order to verify the integrity of the MAP sensor circuits before proceeding with the Component Testing.
Erratic Signal Test
- Ignition OFF, remove the MAP sensor.
- Install a 3A fused jumper wire between the 5-volt reference circuit terminal 1 and the corresponding terminal of the MAP sensor.
- Install a jumper wire between the low reference circuit terminal 2 of the MAP sensor and ground.
- Install a jumper wire at terminal 3 of the MAP sensor.
- Connect a DMM between the jumper wire from terminal 3 of the MAP sensor and ground.
- Ignition ON, with the J 23738-A:
Mityvac or the J 35555:
Metal Mityvac, slowly apply vacuum to the sensor while observing the voltage on the DMM. The voltage should vary between 0-5.2 volts without any spikes or dropouts.
- If the voltage reading is erratic, replace the MAP sensor.