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.
You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
- Ignition OFF, disconnect the HO2S 1.
- Ignition ON, test for 2.9 volts between the HO2S 1 High Signal circuit terminal 6 and ground.
- If more than the specified value, test the circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- If less than the specified value, test the circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the ECM.
- Ignition ON, test for 2.5 volts between the HO2S 1 low signal circuit terminal 2 and ground.
- If more than the specified value, test the circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- If less than the specified value, test the circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the ECM.
- Ignition ON, test for 2.8 volts between the HO2S 1 Output Pump Current circuit terminal 1 and ground.
- If more than the specified value, test the circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- If less than the specified value, test the circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the ECM.
- Ignition ON, test for 2.8 volts between the HO2S 1 Input Pump Current circuit terminal 5 and ground.
- If more than the specified value, test the circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- If less than the specified value, test the circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the ECM.
- Ignition OFF, disconnect the ECM connector X1.
- Ignition OFF, test for infinite ohms between each HO2S 1 circuit terminal and all other HO2S 1 circuit terminals.
- If less than the specified value, repair as necessary.
- If the ECM and all circuits test normal, replace the HO2S 1.