P0141 O2 Sensor Heater Circuit Malfunction
OBD2 error P0141 possible causes
The reasons that may lead to the establishment of code P0141 may be the following:
- Defective oxygen sensor (lambda sensor) Bank 1 sensor 2
- Burnt heater fuse for the second lambda probe or shorted to ground
- Poor electrical connection in the connector of the second lambda sensor
- Defective motor control unit (ECM)
- The wiring system for the O2 heater circuit (oxygen sensor) can be compact.
- The resistance of the oxygen sensor heating element (O2) can be high.
- There may be an internal short circuit in the oxygen sensor heating element.
The code means that there is a problem with the circuit of the heating element of the heated oxygen sensor (lambda sensor). The control module monitors the time it takes to warm up the sensor and starts sending the appropriate signal. The code is triggered when the sensor heats up too long. Water entering the oxygen sensor connector may burn out the fuse of the lambda sensor heater. Before replacing the sensor, check the condition of the fuse and connectors of the heated oxygen sensor. If the sensor and the connector are in order, replacing the sensor (O2 1) usually solves the problem
When will the code be detected?
- The current in the oxygen sensor 2 heater circuit is outside the normal range.
- Check engine light on
- Possibly higher than usual fuel consumption
Oxygen sensors (O2S) or heated oxygen sensors (HO2S) must reach a minimum operating temperature of 400 degrees C in order to obtain an accurate voltage signal. The faster the heated oxygen sensor reaches this temperature, the faster the sensor will start sending an accurate signal to the motor control unit (ECM). To obtain the required temperature, the heating element is located inside the heated oxygen sensor. The ECM controls the oxygen sensor heater based on signals from the engine coolant temperature and engine load. The ECM controls the circuit of the heater, allowing current to flow. The ECM monitors the voltage signal received by the heater circuit and determines the state of the circuit by comparing the detected voltage with the factory specification.
What does code P0141 mean?
Modern vehicles use an oxygen sensor both before and after. The front oxygen sensor (O2S) is located in front of the catalyst. It is used to determine the oxygen concentration in the exhaust gas. This information is used by the ECM to control the engine’s fuel-air mixture. The sensor compares the amount of oxygen in the exhaust with the surrounding air (there is an opening in the sensor that is exposed to the atmosphere). It generates the corresponding voltage, which is transmitted to the ECM. The ECM then controls the injector pulse based on this value.
The oxygen sensor behind the catalyst is used to check the performance of the catalyst. This is done by checking the oxygen content of the exhaust after leaving the catalytic converter. For this reason, further O2 sensors are known as catalyst monitors.
Modern vehicles use heated oxygen sensors (HO2S). These sensors contain a heating element that increases the operating temperature of the sensor more quickly. This allows the ECM to use the input signals earlier in order to control fuel consumption and reduce emissions more accurately. The heater circuit is powered by a relay that closes when the engine is running. The ECM monitors the heater circuit and will turn on the engine control lamp if it finds a problem.
Code P0141 indicates the operation of the 2nd bank sensor of the 1st HO2S heater. This indicates that the ECM has detected a problem with the heater circuit of the oxygen sensor behind it. Row 1 refers to the side of the motor that has cylinder 1. Row 2 is the opposite side of the motor. If you have a four-cylinder, there will only be one bank. The associated code for the other bank is P0161 HO2S Operation of the heater’s 2nd bank sensor. This indicates that the ECM has detected a problem with the 2nd order oxygen sensor heater.