What does P2248 O2 Sensor Reference Voltage Performance Bank 2 Sensor 1 mean?

P2248 is a diagnostic trouble code that indicates a problem with the reference voltage of the O2 sensor in bank 2, sensor 1.

This code is commonly seen in OBD-II vehicles and can be found in various makes and models.

The PCM, or powertrain control module, detects an electrical voltage that is outside the normal expected range for this sensor.

The upstream O2 sensor is responsible for monitoring the air to fuel ratio in each engine bank, and any variation in voltage can affect the engine performance and fuel efficiency.

Common causes of this code include blown fuses, defective sensors, or issues with wiring and connectors.

It is important to address this code promptly to avoid further damage to the vehicle and to restore optimal engine performance.

P2248 Symptoms

  • Diminished fuel efficiency
  • Reduced engine performance
  • Stored misfire codes or lean/rich exhaust codes
  • Service engine soon lamp illumination

Possible P2248 Causes

  • Blown O2 sensor fuse
  • Defective oxygen sensor/s
  • Burnt, chafed, broken, or disconnected wiring and/or connectors

Troubleshooting P2248 error code

  1. Connect a diagnostic scanner to the vehicle diagnostic port and retrieve all stored codes and freeze frame data
  2. Clear the codes and test drive the vehicle until the code is restored or the PCM enters readiness mode
  3. Perform a visual inspection of wiring and connectors, repair or replace damaged wiring
  4. Test O2 sensor voltage at the appropriate connector pin using a digital volt/ohmmeter (DVOM)
  5. Check system fuses and replace blown or defective fuses
  6. Test the corresponding circuit at the PCM connector for voltage
  7. If no voltage is detected, suspect an open circuit between the O2 sensor and PCM
  8. If voltage is detected, suspect a defective PCM or PCM programming error
  9. Start the engine and allow it to reach normal operating temperature
  10. Observe oxygen sensor input data on the data stream using the scanner
  11. Check if the oxygen sensors are functioning normally by observing voltage cycling
  12. Consider defective oxygen sensors if they fail to cycle adequately