P0058 trouble code definition
The definition of the trouble code P0058 is heated oxygen sensor heater control circuit high voltage bank 2 sensor 2.
What the P0058 code means
When this code is stored in the powertrain control module it means that the heater control circuit in the oxygen sensor after the catalytic converter on the cylinder bank not containing cylinder one has higher voltage than expected.
What causes the P0058 code?
The cause of this code is higher voltage than normal being detected by the powertrain control module on the heater control circuit for the bank 2 sensor 2 oxygen sensor. In order to get high voltage there must be a short causing either voltage to be higher than expected or for voltage to be present when the powertrain control module is expecting to see no voltage.
The oxygen sensor heaters are only active on cold starts to help them warm up more quickly to reduce your vehicle's emissions. So if the heaters remain on when the powertrain control module expects them to be off this trouble code will set.
What are the symptoms of the P0058 code?
The main symptom of this code is that the Check Engine Light will be illuminated so the driver will know that their car needs service. Otherwise, the owner really wouldn’t have any idea that there is a problem until they went to get an emissions test.
There are no drivability concerns associated with the type of faults that cause this trouble code to set.
How does a mechanic diagnose the P0058 code?
Since the highest rate of failure for this code is the oxygen sensor itself it is quickest to check the resistance of the heater circuit of the oxygen sensor first. The manufacturer has a specified amount of resistance that each sensor should have. If the resistance measured in the sensor falls out of the specified range it is faulty and should be replaced to fix this trouble code.
If the resistance measure in the sensor checks out okay the next step is to trace out the wiring for the sensor and examine the harness for any signs of damage. It is possible that debris on the road could get under the car and damage the wiring.
Some other things that I have seen are damage from rodents or harnesses being incorrectly routed during other repairs, causing the wires to rub through and short out.
If no visual damage is found, I measure the resistance of the wiring running from the powertrain control module to the sensor itself. If the resistance is more than an ohm there is a problem with the circuit. At this point I would simply replace the wire from end to end. You could attempt to find the exact spot where the high resistance is but chances are it will take a long time and the location of the problem will likely have little to no access to make a proper repair.
Once all these have been eliminated the only remaining piece of the puzzle is the powertrain control module itself.
Common mistakes when diagnosing the P0058 code
The most common mistake diagnosing this code is what I would like to call, “using the parts shotgun”. Also known as “shooting from the hip”, trying to fix something with no diagnostics. Often times the oxygen sensor is replaced without any diagnostics being done. This tends to happen because it is well known that oxygen sensor tend to fail quite often.
How serious is the P0058 code?
The only thing in any real danger from this code setting is the environment. Since the heater for the oxygen sensor is not working, it will take the sensor longer to reach its operating temperature.
What repairs can fix the P0058 code?
There are three repairs that will generally fix this code:
The most common repair, as stated previously, is replacing the oxygen sensor itself.
Next, most common repair is fixing the wiring or connectors associated with the oxygen sensor in question.
The least common repair would be replacing a faulty powertrain control module.
Need help with a P0058 code?
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This article originally appeared on YourMechanic.com as P0058 OBD-II trouble code: HO2S Heater Control Circuit High (Bank 2 Sensor 2) and was authored by Evan Clay.