P2238 - O2 SENSOR POSITIVE CURRENT CONTROL CIRCUIT LOW BANK 1 SENSOR 1

The Oxygen (O2) Sensor provides the Powertrain Control Module (PCM) with information for air/fuel ratio control. The output of this sensor regulates the deviation from the stoichiometric air/fuel ratio. It also controls the injection timing. If the O2 Sensor does not work properly, the vehicle’s computer cannot accurately make the required adjustments to the air/fuel mixture.

DTC P2238 OBDII is set next to the Check Engine light when the PCM detects that the positive current of the Oxygen Sensor 1 on bank 1 is out of range or below the manufacturer’s set value.

• Malfunction Indicator Lamp (MIL) on.
• Poor fuel efficiency.
• An excessive amount of black smoke is expelled from exhaust.
• Other fault codes

Reasons for setting the P2238 OBD2 diagnostic code:

• Oxygen Sensor wires or connectors may be faulty.
• O2 Sensor circuit shorted or open.
• The O2 Sensor is possibly faulty.

To troubleshoot problems related to the P2238 OBDII fault code, try this:

• Check the wiring and connectors associated with the Oxygen Sensor, fix or replace any of these components that are damaged.
• Check that the heater circuit of the O2 Sensor has the same voltage input as the rest of the Oxygen Sensors. If there are considerable differences, the sensor should be replaced.
• Perform voltage tests on the O2 Sensor Verify that there is no short or open circuit to the power relay or ground. Repair as required.