Fault code P0064 – a step-by-step guide to diagnosing and fixing it

Error code P0064 is displayed and the check engine light is on - what does this mean?

The OBD/EOBD system detects a malfunction in the heating circuit of the HO2S sensor (Heated Oxygen Sensor) in bank 1, sensor 3. This DTC P0064 indicates a high current consumption or short circuit in the heater of the rear lambda sensor, which can impair exhaust gas purification.

What causes can this fault code have?

• Defective heating of the lambda sensor bank 1 sensor 3
• Short circuit in the wiring to the lambda sensor
• Damaged plug connections on the oxygen sensor
• Corroded or loose cable connections
• Defective engine control unit (ECU)
• Overvoltage in the electrical system
• Mechanical damage to the sensor wiring

What symptoms occur in parallel with fault code P0064?

• Check engine light: The check engine light is permanently illuminated on the dashboard
• Increased fuel consumption: The vehicle consumes more fuel than usual due to inaccurate sensor readings
• Poor exhaust values: Increased emission values during the emissions test
• Jerky idling: Engine may run unevenly at idle speed
• Delayed sensor activation: Longer warm-up phase of the lambda sensor after a cold start

How can the problem with error code P0064 be rectified?

• Repairing trouble code P0064 requires a systematic diagnosis of the lambda sensor heater.
• Replace lambda sensor bank 1 sensor 3 completely - Replace the defective rear oxygen sensor with a new OEM quality sensor and check that it is correctly seated in the exhaust pipe
• Repair the wiring to the lambda sensor - Check all cables for damage, corrosion or short circuits and replace defective cables completely up to the engine control unit
• Clean and secure plug connections - Disconnect the lambda sensor plugs, clean the contacts with contact spray and ensure that the connections are firmly seated
• Check fuses and relays - Check the associated fuses in the fuse box and replace defective fuses, also test the oxygen sensor heater relays
• Diagnose the engine control unit - Have the ECU checked for defects by a specialist workshop and repaired or replaced if necessary