P2243-O2 SENSOR 1/1 REFERENCE VOLTAGE CIRCUIT/OPEN

For a complete wiring diagram, refer to the Wiring Information.

When Monitored:
With the ignition on and the O2 Sensor 1/1 at operating temperature.
Set Condition:
The Powertrain Control Module (PCM) detects an open on the (K41) O2 Sensor 1/1 Ground circuit for 2.0 seconds.

Possible Causes
(F344) FUSED IGNITION SWITCH OUTPUT CIRCUIT OPEN/HIGH RESISTANCE
(K890) O2 SENSOR 1/1 GROUND CIRCUIT OPEN/HIGH RESISTANCE
OXYGEN SENSOR
POWERTRAIN CONTROL MODULE (PCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

1. DTC IS ACTIVE

1.	Ignition on, engine not running.

2.	With the scan tool, erase DTCs in the PCM.

3.	Start the engine.

4.	Allow the engine to reach normal operating temperature.

5.	Monitor the scan tool for at least two minutes.

6.	With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

Go To 2

Perform the INTERMITTENT DTC diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

2. CHECK THE (F344) FUSED IGNITION SWITCH OUTPUT CIRCUIT VOLTAGE

1.	Turn the ignition off.

2.	Disconnect the Oxygen Sensor harness connector.

3.	Turn the ignition on.

4.	Using a 12-volt test light, probe the (F344) Fused Ignition Swtch Output circuit at the Oxygen Sensor harness connector.

Is the Test light illuminated and bright?

Yes

Go To 3

Repair the (F344) Fused Ignition Swtch Output circuit for an open or high resistance.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

3. CHECK THE (K890) O2 SENSOR 1/1 GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE

1.	Turn the ignition off.

2.	Disconnect the Oxygen Sensor harness connector.

3.	Disconnect the PCM C1 harness connector.

4.	Measure the resistance of the (K890) 02 Sensor 1/1 Ground circuit between the Oxygen Sensor harness connector and the PCM C1 harness connector.

Is the resistance below 5.0 Ohms?

Yes

Go To 4

Repair the (K890) 02 Sensor 1/1 Ground circuit for an open or high resistance.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

4. OXYGEN SENSOR

1.	Turn the ignition off.

2.	Reconnect the PCM C1 harness connector.

3.	Replace the Oxygen Sensor in accordance with the service information.

4.	Start the engine.

5.	Allow the engine to reach normal operating temperature.

6.	Monitor the scan tool for at least two minutes.

7.	With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

Go To 5

Test Complete.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

5. POWERTRAIN CONTROL MODULE

1.	Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor and the Powertrain Control Module.

2.	Look for any chafed, pierced, pinched, or partially broken wires.

3.	Look for broken, bent, pushed out or corroded terminals.

4.	Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

Repair as necessary.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Replace the Powertrain Control Module in accordance with the service information.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

P2243-O2 SENSOR 1/1 REFERENCE VOLTAGE CIRCUIT/OPEN

Possible Causes