Error code P0141 is described as Oxygen Sensor Heater Circuit Malfunction (Bank 1, Sensor 2). This means there is a problem on the O2 sensor on bank 1, and it fails to decrease the time needed to enter closed loop.


Error Code P0141 by definition means the heated circuit of the bank 1 O2 sensor reduces the time required to make a closed loop. As the Oxygen sensor reaches the temperature needed to operate, the O2 sensor responds by changing according to the O2 content of the exhaust around it. The Electronic Control Unit (ECM) determines the time it takes before the O2 sensor starts to operate properly based on the coolant temperature, if there’s too much time, then it will set Error Code P0141.

Common Symptoms

There may be no noticeable symptoms that can affect the performance of the vehicle, so take note of its common symptoms such as:

  • Check Engine light is on
  • Poor fuel economy
  • Vehicle will not pass emission test
  • Elevated NOx emission

Possible Causes

This Error Code can be triggered by one or more of the following things:

  • Short or open ground in the wiring harness
  • Open or internal short in the heater element
  • Oxygen heater circuit wiring and heater element resistance is high
  • Faulty rear most O2 sensor, wiring or connections

Note: A failed catalytic converter doesn’t cause this code. Most often than not, it results in a P0420 code, which means failed converter problem.

How to Check

First thing you need to do to diagnose your vehicle for this error code is to check whether the oxygen sensor heater has failed. This means you need to raise your vehicle to check it.

There are a couple or more ways to check for this problem, but in this entry, we will only discuss the easiest route. Here’s the easiest way to test for this error code.

Test 1 – Testing for 12V to Oxygen Heater

Start by making sure the Oxygen heater sensor gets power. Power comes from 10V to 12V from the Oxygen sensor fuse in the Compartment Fuse box of the engine. Test the circuits of the Oxygen sensor harness connector, which is the connector on the engine wiring harness.

First Step – Raise the vehicle off the ground using jack stands. Always use jack stands to support the vehicle.

Second Step – Unplug the rear O2 sensor. Your vehicle has two O2 sensors, one before the catalytic converter, and another after it. In this test, we will check the sensor after the catalytic converter.

Third Step – Find the Pink wire. This wire is the circuit D, and will have the letter ‘D’ marking.

Fourth Step – With the engine Off and key On, the wire should have 10V to 12V DC

Let’s check your test results:

If the Pink wire gets 10V to 12V – this means the heater element in the oxygen sensor receives power. You need to proceed to Test 2, which will test the whether the PCM is grounding circuit C.

If the Pink wire did NOT get 10V to 12V – this means your Oxygen sensor fuse in the vehicle’s Engine Compartment box is damaged (blown), and you need to replace it.

Many times when the fuse is damaged, your scan tool will also register Error Code P0135 DTC, since it also feeds the front O2 sensor with power.

Test 2 – Testing for Ground Circuit of O2 Heater

First thing you need to do is make sure the PCM provides a ground on the black wire with white strip of the engine’s wiring harness O2 sensor connector. This wire is the circuit C of the O2 sensor connector, and it has a marking for itself, and it is the engine’s wiring harness.

First Step – Unplug the rear O2 sensor.

Second Step – Find the wire with circuit C label.

Third Step – Set your multimeter in Volts DC mode, then, hook up the red multimeter to the + end of the battery. Next, hook up the black lead to the circuit C wire of Oxygen sensor connector’s engine wiring harness.

Fourth Step – With the engine Off and key On, the wire should have 10V to 12V DC.

Let’s check your test results:

If the multimeter registered the right voltage – This means the O2 sensor’s heater element is getting round. Thus, you need to check the O2 sensor heater element’s resistance and check if it is shorted ‘open’. At this stage, you need to check the Ohming of the Oxygen element heater, which would be Test 3.

If the multimeter didn’t register the right voltage – This means your PCM is bad (this can be rare), or the wires between the Oxygen sensor and PCM is shorted open.

Note that you may need to check the entire black wire with white stripe between the PCM connector and the O2 sensor connector.

Test 3 – Oxygen Heater Element’s Ohming

This test checks whether the O2 sensor for bank 1 sensor 2 if fired or not. You will test the Oxygen sensor and not the sensor harness connector.

First Step – Unplug the O2 sensor from the wiring harness connector of the engine.

Second Step – Find the wires of the Oxygen sensor with circuits C and D.

Third Step – Using your multimeter set at Ohm mode, check the circuit’s resistance:

Remember that you are testing the O2 sensor, and if everything is good, you should have 4. 5 Ω (Ohms). If it shows the letters OL, then that means your heater element is damaged (fried).

Let’s check your test results:

If result shows your multimeter has resistance – this means that the O2 sensor’s heater element is in good condition.

If result shows the letters ‘OL’ – this means your Oxygen sensor is damaged, and you need to replace it

How to fix

As said in the three tests above, the solution to Error Code P0141 is to replace the damaged components, which is usually the O2 sensor (short that happens internally in the sensor or short open).

You may also need to fix short or open or high resistance in harness connectors or wiring harness.

Parting Tips

Checking and repairing for error code P0141 is actually pretty simple.

For more information about this error code, or other error codes, feel free to Contact US.