Circuit/System Testing

WARNING: This page is about a different car, the 2008 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

Verify the integrity of the entire air induction system including all turbocharger components by inspecting for the following conditions:
- Any damaged components
- Loose or improper installation including the flexible ductwork of the turbocharger and the CAC
- An air flow restriction
- Any vacuum leak
- In cold climates, inspect for any snow or ice buildup at the BARO port on the ECM
- A restriction in the MAP sensor port
Ignition OFF, disconnect the harness connector at the MAP sensor.
Ignition OFF for 90 seconds, test for less than 5 ohms between the low reference circuit terminal 2 and ground.
- If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 1 and ground.
- If less than the specified range, test the 5-volt reference 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 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
Verify the scan tool MAP Sensor parameter is less than 1 kPa.
- If greater than the specified range, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the ECM.
Install a 3A fused jumper wire between the signal circuit terminal 3 and the 5-volt reference circuit terminal 1. Verify the scan tool MAP Sensor parameter is greater than 254 kPa.
- If less than the specified range, test the signal circuit terminal 3 for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
If the circuits test normal, test or replace the MAP sensor.