Fault code P0057 – a step-by-step guide to diagnosing and fixing it

Error code P0057 is displayed and the check engine light is on - what does this mean?

The OBD/EOBD system has detected a low circuit in the heater of lambda sensor 2 (bank 2). This DTC P0057 indicates a problem with the heating circuit of the downstream oxygen sensor, which is located after the catalytic converter. The exact designation and position of the affected sensor may vary for different manufacturers.

What causes can this error code have?

• Defective lambda sensor heater
• Damaged or burnt-out cable to the lambda sensor
• Corroded or loose plug connections
• Faulty fuse in the lambda sensor heating circuit
• Faulty engine control unit (ECU)
• Short circuit in the wiring
• Defective lambda sensor itself
• Overvoltage in the electrical system

What symptoms occur in parallel with fault code P0057?

• Increased fuel consumption: The vehicle consumes more fuel than usual because the mixture control is impaired.
• Uneven engine running: The engine runs unevenly or jerks, especially when idling or at low engine speeds.
• Poor exhaust emission values: Increased emission values are detected during the exhaust emission test.
• Starting problems: The vehicle takes longer to start, especially when the engine is cold.
• Loss of power: Reduced engine power and poor acceleration.

How can the problem with error code P0057 be rectified?

• Repairing trouble code P0057 requires a systematic approach to identify the defective component.
• Replace lambda sensor bank 2 sensor 2 completely, including heating element and sensor part, to eliminate both mechanical and electrical defects
• Check all wiring between ECU and lambda sensor and replace damaged cable sections, checking all connections for corrosion and tightness
• Locate the fuse in the lambda sensor heating circuit and replace it if it blows, then determine and eliminate the cause of the overload
• Clean the plug connections on the lambda sensor, treat with contact spray and screw tight to eliminate contact resistance
• Have the engine control unit checked for defects and, if necessary, replace or reprogram if other components are OK
• Measure the voltage supply of the entire lambda sensor system with a multimeter and search for the cause in the vehicle electrics in the event of deviations