OBD-II Trouble Code Description for P0052 Toyota

HO2S Heater Control Circuit High

What does this mean?

OBD2 Code P0052 Toyota definition:
A P0052 Toyota DTC (diagnostic trouble code) definition:the O2 sensor (oxygen sensor) located on Bank 2 in front of the catalytic converter. There is also an oxygen sensor behind the converter which is Sensor #2. Bank 2 is the side of the engine that doesn’t contain cylinder #1. This O2 sensor #1 may also be refered to as an air/fuel ratio sensor since on some vehicles it is. The sensor detects the amount of oxygen in the exhaust gas compared to the outside air and then vehicle’s computer adjusts the air/fuel ratio going into the engine. The sensor is less effective when the exhaust gas temperature is low, so it includes a heater which is activated to help get better readings from the O2 sensor. Essentially this P0052 Toyota code means that the resistance of the heater circuit is higher than normal. In some cases, that resistance level must be higher than 10 A to trigger the DTC code. Note, this code is very similar in nature to P0031 Toyota, P0032 Toyota, and P0051 Toyota

Symptoms

Possible sumptoms of OBD code P0052 Toyota
Most likely you’ll not notice any symptoms other than the MIL (malfunction indicator lamp, a.k.a. the check engine light) will illuminate.

Causes

Possible causes of OBD code P0052 Toyota
A P0052 Toyota DTC trouble code may be caused by one or more of the following: A short in the heater circuit in the sensor A failed O2 sensor heater Wiring/connectors broken/frayed leading to sensor and/or relay Failed PCM/ECM

Possible Solutions

To fix a P0052 Toyota DTC code, you’ll need to do a proper diagnosis. To do that, you’ll want to inspect the wiring and connectors leading to the sensor. Also if equipped with a heater relay and fuse, you’ll want to check those as well. Use a digital volt ohm meter to: check for 12 volts at the heater circuit feed (hint: unplug the sensor and check at the wiring connector to do this measurement) check the ground circuit for continuity measure the resistance of the heater circuit (done on the sensor itself) measure the resistance and voltage of the wiring Refer to a service manual for the correct specifications (volts, ohms) for your vehicle. On some Toyota vehicles this code is triggered when the resistance of the heater circuit is above 10 A. With that said, a common fix for this DTC is to replace the air/fuel (O2 oxygen) sensor #2 on bank 1. Please keep in mind that OEM (original equipment) replacement sensors are recommended (from the dealer). Aftermarket sensors can be less reliable and of poorer quality (not always, but more often). There’s also a chance that replacement parts for the P0052 Toyota code may also fall under a federal emissions warranty (check with your dealer to see if it’s covered).

Related Codes

P0031 Toyota P0032 Toyota P0051 Toyota