P2237-O2 SENSOR 1/1 PUMP CELL CURRENT 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 (K89) O2 Sensor 1/1 Positive Current Control circuit for 2.0 seconds.

Possible Causes
(K89) O2 SENSOR 1/1 NEGATIVE CURRENT CONTROL CIRCUIT OPEN/HIGH RESISTANCE
OXYGEN SENSOR
POWERTRAIN CONTROL MODULE (PCM)

1. DTC IS ACTIVE

1.	Turn the ignition on.

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

3.	Start the engine.

4.	Allow the engine to reach normal operating temperature.

5.	Test drive the vehicle and monitor the scan tool.

6.	With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

2. CHECK THE (K89) O2 SENSOR 1/1 NEGATIVE CURRENT CONTROL 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 (K89) O2 Sensor 1/1 Negative Current Control circuit between the Oxygen Sensor harness connector and the PCM C1 harness connector.

Is the resistance below 5.0 Ohms?

Yes

Repair the (K89) 02 1/1 Negative Current Control 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. 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.	Turn the ignition on.

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

6.	Start the engine.

7.	Allow the engine to reach normal operating temperature.

8.	Test drive the vehicle and monitor the scan tool.

9.	With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

4. 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

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).