Circuit/System Testing
WARNING: This page is about a different car, the 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
- Verify that the induction system components are properly positioned and connected.
- Ignition OFF, disconnect the harness connector at the MAF/IAT sensor.
- Ignition OFF for 90 seconds, test for less than 5 ohms between the MAF sensor ground circuit terminal B and ground.
- If greater than the specified range, test the MAF sensor ground circuit for an open/high resistance.
- Test for less than 5 ohms between the IAT low reference circuit terminal D 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.
- Disconnect the harness connector at the intake air pressure and temperature sensor.
- Test for less than 5 ohms between the low reference circuit terminal 1 or A 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.
- Disconnect the ECM.
- Test for less than 5 ohms between the IAT sensor signal circuit terminal E and the ECM connector X2, terminal 50.
- If greater than the specified range, test the IAT sensor signal circuit for an open/high resistance.
- Test for less than 5 ohms between the IAT sensor 2 signal circuit terminal 2 or B and the ECM connector X1, terminal 86.
- If greater than the specified range, test the IAT sensor 2 signal circuit for an open/high resistance.
- If the circuits test normal, test both the IAT sensor and the IAT sensor 2.