P0057 Error Code: An In-depth Analysis on Symptoms, Causes, and Fixes

All vehicles manufactured in 1996 upwards are equipped with an onboard diagnostic computer, which monitors and regulates various components of the car for efficient performance. This system relies on various car sensors to get extra data from the vehicle.

This data is then used to give commands to system components and notify the driver of any malfunction or problem. If the vehicle malfunctions, a certified mechanic or technician will track down the problem and the cause. He will do so without lifting a finger by plugging in a scan tool on the OBD2 port outlet.

When the car circuits or sensors detect out-of-range information, it’ll notify the car computer, storing the problem as codes. Diagnostic trouble codes are a combination of letters and numbers that show the origin and type of malfunction. In this article, we’ll discuss the meaning, symptoms, causes, diagnosis mistakes, how to diagnose and repair error code P0057.

Code P0057 Definition

H02S2 Heater Control Circuit Low (Bank 2, Sensor 2)

What Does P0057 Mean?

Diagnostic trouble code P0057 sets when the onboard car computer detects a low voltage on the oxygen bank 2 sensor 2.  This code may also mean a malfunction on the oxygen sensor heater circuit.

Which side is bank 2 sensor 2? “Bank 2” here refers to the cylinder head that houses the no.2 spark plug, whereas, sensor 2 refers to the downstream O2 sensor (the sensor after the catalytic converter).

Note: P0057 Nissan may mean a different thing from P0057 Toyota. Hence, you need to get your specific vehicle repair database or repair manual for the exact meaning of the error code on your vehicle.

Oxygen sensors measure and regulate the oxygen in the exhaust system. They are located upstream on the exhaust manifold and downstream on the exhaust pipe after the catalytic converter. 

The car computer collects data from the oxygen sensors and uses this data for streamlining, controlling, and regulating air/fuel mixture for an efficient combustion process. The ECM uses the data from downstream sensor 2 to monitor the catalytic converter.

What Are the Symptoms of Code P0057?

The P0057 error code problem comes with slim symptoms. Most times, you may not notice any sign. Here are a few symptoms you should watch out for;

What Cause of Code P0057?

The PCM can set P0057 for various reasons. Here are some of the potential causes below;

How Serious Is Code P0057?

 P0057 fault code is a moderate case that will not prevent your vehicle from moving. However, it will lead to emission test failure. The exhaust emission will increase when you start the car but will normalize as the car warms up.

The most common issues you’ll experience are bad gas mileage, HO2S sensor issues, and poor engine performance. You’re better off fixing these issues than letting them escalate to more significant repair issues. 

Code P0057 Common Diagnosis Mistakes

When diagnosing error code P0057, the car owners and mechanics make the most common diagnostic mistake. This is assuming and replacing the O2 sensor without confirming whether or not the sensor is good.

Although this often fixes the problem, sometimes the culprit lies in the blown fuses, disconnections, or corrosion on the wiring connectors.

Tools Needed to Diagnose Code P0057

Here are a few tools needed to diagnose a P0057 trouble code;

How to Diagnose and Repair Code P0057

Diagnose and reset the registered fault code with an OBD2 scan tool, and drive-test the vehicle and see if the code will reappear. If the P0057 fault code returns and you wonder how do you fix P0057, follow the outlined guides below;

Diagnosing procedures vary based on individuals and manufacturers. I start the diagnosis by checking the oxygen sensor bank 2 sensor 2 wiring harness and connectors for cuts and corrosion. A cut or debris on the wire because of road conditions could be the culprit.

Once you have found out there’s no cut or debris on the wiring connections, move over to the oxygen sensor bank 2 sensor 2 and inspect the heating circuit.

To do this, disconnect the O2 sensor and measure the resistance with an ohmmeter. The specified ohms may vary depending on your vehicle, but it should be around four to five ohms. If you get OL [out of limit] or INF [Infinite] resistance on the readings, it shows you have a defective heater that needs replacement.

If the sensor is working fine, you need to check the wires that connect the sensor to the powertrain control module. Disconnect the wiring connector from the powertrain control module and measure the resistance.

The resistance should be less than an ohm. If the reading gives 1-2 ohms of resistance, it means there’s a partially broken wire from the insulation. And that could be responsible for the problem. Repair, here, requires replacing the wires.

If there’s no broken, burned, or corroded wire, the issue is likely from the power control module. You may have a burned or corroded switch on the power control module. 

Repairs

Same Problems with different Error Code

These are other codes that point to the same or related problem with the P0057 code;

Final word

At this juncture, we’ve explained the meaning of error code P0057 and outlined the causes, symptoms, diagnosis mistakes, and how to diagnose and repair. The procedure is as simple as tracing and replacing a misfiring ignition coil. 

The severity of error code P0057 is low. However, it doesn’t mean you should leave it unattended because it may cause major repairs in the long run.