Trouble code solution P0154: decoding, causes, resetting, meaning

Contents

Technical description and explained code P0154
Symptoms of vehicle malfunctions
Factors that can cause this error code
How to fix or reset OBD-2 code P0154
Diagnose and repair of problems
On which vehicles does this problem occur most frequently
Video

Fault code P0154 is called “O2 Sensor Circuit No Activity Detected (Bank 2, Sensor 1)” 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 P0154

This Diagnostic Trouble Code (DTC) is a generic powertrain code. Error P0154 is considered a generic code because it applies to all makes and models of vehicles. Although the specific repair steps may vary slightly from model to model.

The powertrain control module (ECU) provides a reference voltage of about 450 mV in the oxygen sensor signal circuit. During cold weather the ECU detects a high internal resistance of the sensor.

As the sensor warms up, the resistance decreases and the sensor begins to produce a voltage based on the oxygen content of the exhaust. When the ECU detects that the time it takes for the sensor to warm up is greater than one minute. Or that the voltage is inactive (not reading beyond 391-491 mV). The sensor is detected as inactive or open and sets the code P0154.

The rear oxygen sensor O₂ (bank 2, sensor 1) is located in the exhaust manifold. Its function is to detect the amount of oxygen in the exhaust gases, which is compared with the outside air.

Symptoms of vehicle malfunctions

The main signal that an error P0154 has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.

It can also be warning signs such as:

Check engine control lamp on the control panel will light up.
The car does not run well, there is not enough engine power.
There is black smoke coming out of the exhaust pipe.
Increased fuel consumption.
RPMs do not hold up well, jerking when driving.

Factors that can cause this error code

The error code P0154 can mean that one or more of the following problems have occurred:

The sensor O₂ (oxygen) is defective.
Heater circuit in the sensor O₂ is defective.
Connection or connector to the sensor is broken or frayed.
Heater circuit fuse blown.
Holes in exhaust system (muffler).
ECU failure.

How to fix or reset OBD-2 code P0154

Some suggested steps for troubleshooting and fix the error code P0154:

A severely worn and rusted muffler should be replaced.
Check wiring and connectors for problems.
Fuse blown due to too high amperage. The sensor needs to be replaced, and the blown fuse needs to be replaced.
Replace the ECU, this should only be done as a last resort. After all other possibilities have been considered.

The most common solution when troubleshooting P0154 is to replace the oxygen sensor. But this should be done after excluding all possible options.

Diagnose and repair of problems

The most common cause of error P0154 is an oxygen sensor failure. It is necessary to conduct a thorough analysis and consider all possible causes of the error before replacing the sensor. The first thing to do is to check the electrical wires and the oxygen sensor connector.

Every time after the repair work is done, you should clear the ECU memory of the error codes. After that, you should test the car to see if the P0154 error reappears. This will help determine if the problem has been resolved.

If the diagnostics show that everything is fine with the oxygen sensor, as well as the electrical wires and connections. It is necessary to check the exhaust pipe and the heater fuse of the sensor.