Fault code P0167 is called “O2 Sensor Heater Circuit Malfunction (Bank 2, Sensor 3)” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.
Technical description and explained code P0167
This diagnostic trouble code (DTC) is a generic code. Error P0167 is considered a generic code because it applies to all makes and models of vehicles. Although the specific repair steps may vary slightly depending on the model.
The fault means that the heated circuit in the oxygen sensor on block 2 is reducing the time it takes to enter the closed circuit. Sensor #3 will be the third sensor after the engine.
When the air heats up and reaches operating temperature. The oxygen sensor responds by switching according to the oxygen content of the surrounding exhaust. The ECM monitors how long it takes for the oxygen sensor to start switching.
It determines, based on the coolant temperature, how much time has elapsed before the sensor has responded. If a lot of time has elapsed before the oxygen sensor starts working properly, error P0167 will appear.
Symptoms of vehicle malfunctions
The main signal that an error P0167 has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.
It can also be warning signs such as:
- The “Check engine” control lamp on the control panel will light up.
- Increased fuel consumption is possible.
Fault P0167 is considered serious because failure of the oxygen sensor can lead to big problems. For example, the vehicle’s ECM will not be able to properly adjust the fuel to air ratio in the mixture flowing into the vehicle’s engine.
Factors that can cause this error code
The error code P0167 can mean that one or more of the following problems have occurred:
- Damaged oxygen sensor (lambda probe), bank 2, sensor 3.
- Second lambda probe heater fuse blown or shorted to ground.
- Bad electrical connection in the connector of the second oxygen sensor.
- Open or short to ground in wiring harness.
- Engine control module (ECM) is defective.
- Possible short in heater O₂ (oxygen sensor) wiring system.
- Resistance of the oxygen sensor (O₂) heater element may be high.
- The oxygen sensor heater element may have an internal short circuit.
How to fix or reset OBD-2 code P0167
Some suggested steps for troubleshooting and fix the error code P0167:
- Visually inspect the electrical wires and oxygen sensor connector 3 (bank 2).
- Read all stored data and error codes with an OBD-II scan tool. Clear the memory of the error codes and test drive the vehicle. This will help you find out if the P0167 code appears again.
- Review the oxygen sensor data to see if it is working.
- Measure the voltage in the oxygen sensor heater circuit 3 (bank 2).
- Measure the resistance in the oxygen sensor heater circuit 3 (bank 2) and compare the value to the manufacturer’s specification.
- Locate the fuse diagram and check the corresponding fuse for continuity.
Diagnose and repair of problems
Error code P0167 means that there is a problem with the heated oxygen sensor (lambda probe) heating circuit. The control module monitors the time it takes for the sensor to warm up. And starts to send the corresponding signal.
The code is triggered when the sensor gets too warm for too long. Water entering the oxygen sensor connector may blow the lambda probe heater fuse.
Before replacing the sensor, check the condition of the oxygen sensor heater fuse and connector. If the fuses and connector are OK, replacing the sensor (O₂ bank 2) usually solves the problem.
On which vehicles does this problem occur most frequently
Fault code P0167 can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:
- Ford (Focus, Transit)
- Mazda (3)
Fault code P0167 can sometimes be found with other errors. The most common are the following: P0033, P0100, P0162, P0163, P0164, P0165, P0166, P0169.