PRA vs PRB sensor differences

PRA and PRB ECUs use different sensor wiring. Wideband sensors (PRB) require precise heater control, while narrowband sensors (PRA) operate with standard heater control. Incorrect wiring may result in sensor or ECU damage. Verify ECU type and refer to the correct wiring diagram before installation.

PRA narrowband wiring diagram

PRB wideband wiring diagram

Convert wiring from PRA to PRB

• Disconnect the sensor ground from E4 (SG3) and connect it to A16 (AFS−).
• Disconnect the sensor heater +12V from the ignition and connect it to A22 (AFSHTC+).
• Add a heating control relay.
• Connect the relay control input to E8 (AFSHTCR).
• Connect the relay output to A22 (AFSHTC+).

Convert wiring from PRB to PRA

• Disconnect the sensor ground from A16 (AFS−) and connect it to E4 (SG3). Route it alongside the existing wire.
• Disconnect the sensor heater control from E8 (AFSHTCR) and connect it to A5 (GND). Route it alongside the existing wire.
• Cut the wire going to A22 (AFSHTC+) close to the ECU plug.