Guide To P0056 OBD Error Code Solutions

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The major symptom of this code is that, emission coming from the vehicle could increase due to the oxygen sensor taking longer to reach its operating temperature. This increase in emissions is what causes the Check Engine Light to come on so that the vehicle can be repaired as soon as possible.

The P0056 trouble code signifies that there is a problem with the heater control circuit in the bank 2 sensor 2 oxygen sensor.

OBD-II Code P0056 is defined as a HO2S Heater Control Circuit. The purpose of the oxygen sensor is to measure the oxygen content in the exhaust gases after they leave the combustion process of the engine. The oxygen sensor must be at a certain temperature in order for this information to be accurate. The oxygen sensor has a heater wire inside to help bring the sensor up to temperature quicker.

Heated Oxygen Sensors (HO2S) need to reach a minimum operating temperature of 750 degrees Fahrenheit to generate an accurate voltage signal. The faster the heated oxygen sensor reaches that temperature the faster the sensor will start sending an accurate signal to the Engine Control Module (ECM).

What causes problem with the HO2S Heater Control Circuit?

• Faulty Heated Oxygen Sensor due to circuit problems
• Sensor wiring and harness short problem
• Poor electrical connections to the sensor
• Heated Oxygen Sensor (H2OS) damaged circuit fuse
• Problematic Engine Control Module hampering the engine performance

1. Heated Oxygen Sensor - The heated oxygen sensor can affect the fuel/air mixture, engine timing and engine combustion intervals and immediate replacement is advisable.
2. Heated Oxygen Sensor Harness - OBD Error Code P0056 may also occur if the sensor harness is damaged and is unable to transmit correct data. Buy quality auto parts from us.
3. Heated Oxygen Sensor Connector - A faulty Oxygen Sensor Connector can cause combustion problems in the engine. Replace your old connectors now.
4. Heater Circuit Fuse - Damaged fuses affect the circuit performance and results to inefficient functioning. Replace faulty fuses immediately.
5. Engine Control Module - OBD Error Code P0056 can also be due to faulty ECMs. Thus, replace damaged ECM now!
6. Powertrain Control Module - Problems with the powertrain can be a rare reason for flashing of OBD Error P0056 code. Find all the Powertrain related parts with us.
7. Catalytic Converter - Catalytic converters can overheat and hamper the engine performance. Replace your old catalytic converter now!
8. Diagnostic Tool - Pick the correct diagnostic tools to get your car problems pointed out easily. Our diagnostic tools collection will come handy to do so, so why not have a look?
9. Auto Switches & Sensors - Defective switches or faulty sensors should be immediately replaced as they might hamper the performance of the related components.

The most common symptoms include MIL (Malfunction indicator lamp) illumination. It is difficult to notice any other symptom associated with the failure of the heated circuit since it only runs momentarily when the vehicle is first started. This sensor is also after the catalytic converter, so it can affect the air/fuel ratio input to the PCM/ECM and is primarily used to check the efficiency of the catalytic converter

Following are the steps to be followed to correct the OBD code P0056 error;

• Inspect the oxygen sensor wiring for damaged or loose wiring to the sensor and test the resistance of the heater circuit using a wiring diagram for reference.
• If the heater circuit inside the sensor has some resistance present, excessive resistance or an over limit reading, it would indicate faulty oxygen sensor will need to be replaced.
• Check for power supply to the oxygen sensor. If no power is present at the connector during cold start, there may be a problem with the power supply circuit to the oxygen sensor or the PCM itself which need immediate replacement. 

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• The first step is to complete a visual inspection of the wiring for the bank 2 sensor 2 oxygen sensor.
• Many times, this code can be set due to damaged wirings which are wrongly routed or damaged by road hazards.
• The next step is to measure the resistance of the heater circuit in the oxygen sensor itself.
• If the resistance of the sensor is not as per the specifications then it is faulty and the oxygen sensor is needed to be replaced.
• If the sensor checks out to be in perfect condition, then we must check the resistance of the rest of the circuit from powertrain control module to the connector of the bank 2 sensor 2 oxygen sensor. A normal reading for wiring is less than half an ohm.
• If the rest of the wiring is found to be good then the likely problem is with the powertrain control module itself.

Common Mistakes When Diagnosing OBD Code P0056

Though the sensor itself is generally the cause of P0056, using the proper tools and following the complete diagnostic procedure without skipping any steps is required as to avoid unneeded repairs. Monitoring the sensor data from the scan tool live data stream is the only way to check for proper operation, and the sensor should not be replaced until it is tested.

P0056 has easily managed symptoms but like any other code, it should be repaired at the earliest convenience. In rare cases where the vehicle runs poorly and the fuel economy goes down, caution is advised when driving to avoid any issues.