P2A00

P2A00-O2 SENSOR 1/1 CIRCUIT PERFORMANCE





For a complete wiring diagram Consult Diagrams/Electrical

- When Monitored:
With the ignition on.

- Set Condition:
The ECM detects an open or implausible voltage on the (Z43) O2 1/1 Negative Current Control for 2.0 seconds.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.Initial Inspection and Diagnostic Overview

Diagnostic Test

1. DTC IS ACTIVE
Ignition on, engine not running.
With the scan tool, Clear DTCs in the Engine Control Module (ECM).
Start the engine.
Allow the engine to reach normal operating temperature.
Monitor the scan tool for at least two minutes.
With the scan tool, select View DTCs.
Is the status Active for this DTC?

Yes

- Go To 2

No

- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.Intermittent Condition

2. (Z43) O2 1/1 NEGATIVE CURRENT CONTROL CIRCUIT SHORTED TO VOLTAGE




Turn the ignition off.
Disconnect the Oxygen Sensor harness connector.
Disconnect the Engine Control Module (ECM) harness connector.
Remove the ASD Relay from the PDC.
Connect a jumper wire between cavity 30 and cavity 87 of the ASD Relay Connector.
Turn the ignition on.
Measure the voltage of the (Z43) O2 1/1 Negative Current Control circuit in the Oxygen Sensor harness connector.
Is there any voltage present?

Yes

- Repair the (Z43) O2 1/1 Negative Current Control circuit for a short to voltage.
- Perform the ECM Verification Test Ver. 1. Verification Tests

No

- Go to 3

3. (Z43) O2 1/1 NEGATIVE CURRENT CONTROL CIRCUIT SHORTED TO GROUND




Turn the ignition off.
Remove the jumper wire and install the ASD relay.
Measure the resistance between ground and the (Z43) O2 1/1 Negative Current Control circuit in the Oxygen Sensor harness connector.
Is the resistance above 1000 ohms?

Yes

- Go to 4

No

- Repair the (Z43) O2 1/1 Negative Current Control circuit for a short to ground.
- Perform the ECM Verification Test Ver. 1. Verification Tests

4. (Z43) O2 1/1 NEGATIVE CURRENT CONTROL CIRCUIT SHORTED TO THE (A15) FUSED ASD RELAY OUTPUT CIRCUIT




Measure the resistance between the (Z43) O2 1/1 Negative Current Control circuit and the (A15) Fused ASD Relay Output circuit in the Oxygen Sensor harness connector.
Is the resistance above 1000 ohms?

Yes

- Go to 5

No

- Repair the (Z43) O2 1/1 Negative Current Control circuit for a short to the (A15) Fused ASD Relay Output circuit.
- Perform the ECM Verification Test Ver. 1. Verification Tests

5. (Z43) O2 1/1 NEGATIVE CURRENT CONTROL CIRCUIT SHORTED TO THE (K99) O2 1/1 HEATER CONTROL CIRCUIT




Measure the resistance between the (Z43) O2 1/1 Negative Current Control circuit and the (K99) O2 1/1 Heater Control circuit in the Oxygen Sensor harness connector.
Is the resistance above 1000 ohms?

Yes

- Go to 6

No

- Repair the (Z43) O2 1/1 Negative Current Control circuit for a short to the (K99) O2 1/1 Heater Control circuit.
- Perform the ECM Verification Test Ver. 1. Verification Tests

6. (Z43) O2 1/1 NEGATIVE CURRENT CONTROL CIRCUIT OPEN OR HIGH RESISTANCE




Measure the resistance of the (Z43) O2 1/1 Negative Current Control circuit between the Oxygen Sensor harness connector and the Engine Control Module (ECM) harness connector.
Is the resistance below 10.0 ohms?

Yes

- Go to 7

No

- Repair the circuit for an open circuit or high resistance.
- Perform the ECM Verification Test Ver. 1. Verification Tests

7. OXYGEN SENSOR
Connect the Engine Control Module (ECM) connector.
Replace the Oxygen Sensor.
Start the engine.
Allow the engine to reach normal operating temperature.
Monitor the scan tool for at least two minutes.
With the scan tool, select View DTCs.
Is the status Active for this DTC?

Yes

- Go to 8

No

- Test Complete.
- Perform the ECM Verification Test Ver. 1. Verification Tests

8. ENGINE CONTROL MODULE (ECM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors the Oxygen Sensor and the Engine Control Module (ECM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Search for any Technical Service Bulletins that may apply.
Were any problems found?

Yes

- Repair as necessary.
- Perform the ECM Verification Test Ver. 1. Verification Tests

No

- Replace the Engine Control Module (ECM).
- Perform the ECM Verification Test Ver. 1. Verification Tests