P0064: HO2S Heater Control Circuit High (Bank 2, Sensor 3)

What does P0064 mean?

P0064 is a diagnostic trouble code indicating "HO2S Heater Control Circuit High (Bank 2, Sensor 3)". The ECU is reading a voltage that is above the expected range. This can be caused by a short to power in the wiring, a failed sensor, or a connector issue in the o2 sensors.

Symptoms you may notice

• Check engine light (MIL) illuminated on dashboard
• Intermittent warning lights
• Erratic gauge readings

Common causes

• Damaged or corroded wiring harness
• Loose or disconnected electrical connector
• Failed o2 sensors sensor or actuator
• Blown fuse in the related circuit
• Poor ground connection

What should you do?

This code sits in an engine peripheral, typically emissions or forced induction. It will not take braking or steering away, but it can put the car into limp mode, cost you fuel and fail a roadworthy. Book it in rather than clearing it and hoping.