Why is my check engine light on and what does code P0141 mean?
What does it mean if you have a P0141 code and your check engine light is on? P0141, “O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2),” means something is preventing your car’s Bank 1 number 2 oxygen (O2) sensor’s heated circuit from working correctly.
In this video, our mechanic shows you how to inspect and test your oxygen sensors. You’ll also find out how to check their circuits and wiring, fuses, and other areas to figure out what’s causing the P0141 code.
Check Engine Light? O2 Sensor Heater Circuit Malfunction – Code P0141
What Is Code P0141 and What Does It Mean?
If your car has a P0141 diagnostic trouble code, the heated circuit found in the downstream O2 sensor 2 in Bank 1 is malfunctioning. Our mechanic explains that heated circuit’s role beginning at 0:17 in the video above.
That heated circuit isn’t heating up, which means the O2 sensor itself may be faulty or failing, or that its circuits, wiring, or connectors could be faulty or broken. A blown fuse or Powertrain Control Module (PCM) issue could also prevent the circuit from heating properly.
Can I Drive with Code P0141? How Serious Is It?
Depending on what’s causing the issue that triggered P0141, your engine may become stuck in “open loop” mode, which means its burning more fuel than usual. It’s best to address a P0141 code as soon as possible to avoid other related repairs.
What Are Typical P0141 Code Symptoms?
- Your check engine light is on
- Rough-running engine
- Poor fuel economy
What Are the Common Causes of P0141?
- Power circuit wiring issue or damage, such as broken wiring preventing power from reaching the fuse box
- Blown fuse
- PCM circuit break or other wiring issue
- PCM issue
- Faulty or failing Bank 1, o2 Sensor 2 heated circuit
- Faulty or failing Bank 1, o2 Sensor 2
- Remote starter not sending power to the o2 sensor’s circuits
How Do I Diagnose and Fix Code P0141?
How to diagnose and fix code p0141
- Inspect and run power circuit tests
1. Use a test light to check the fuse to determine if the issue is power-related
You’ll want to turn your key to the on position (your car doesn’t have to be running). Use a test light to test both O2 sensor fuses (depending on your vehicle, these two fuses will be referred to as fuse 1 and fuse 2 or fuse A and fuse B). Our mechanic walks you through how to do this test at 1:44 in the video above. If the test light lights up, you’ll know that particular fuse isn’t causing the problem that triggered P0141.
If the power circuit isn’t working, there could be a break in its wiring, or another issue preventing power from getting to the fuse box, or you could even have a blown fuse.
2. Inspect Bank 1, Sensor 2’s wires and connector for fraying or damage
Our mechanic shows you how to locate your o2 sensors, and the Bank 1, o2 sensor 2 specifically, beginning at 2:17. The vehicle our mechanic works on in the video has four o2 sensors: Two on the driver’s side and two on the passenger side. The Bank 1 sensors are referred to as Bank 1, Sensor 1, and Bank 1, Sensor 2; the Bank 2 sensors: Bank 2, Sensor 1, and Bank 2, Sensor 2.
Check Bank 1, Sensor 2’s wiring (2:59)—our mechanic notices some “chafing” on the outside part of one wire, but it doesn’t look like any of the wires are broken.
Also, inspect this sensor’s electrical connector (3:12). Disconnect the connector and look at its terminals to see if they look like they’re spread apart or green, either of which indicates an issue.
3. Use a test light to check the fuse to determine if the issue is ground-related
With your key still on, use a test light to test the ground (our mechanic shows you how to do this beginning at 3:29).
- Inspect and run PCM circuit tests
Use a multimeter or test light to test the resistance
As our mechanic explains at 4:11, you could test the ground circuit using a multimeter, but the results aren’t always as accurate as using a test light (4:21).
If the test light doesn’t light up, this could mean that there’s a break in the wiring, or that something is wrong internally in the PCM.
If both circuits are working, then the oxygen sensor’s heated circuit is causing the problem and triggering the P0141 code, which means you’ll need to replace that O2 sensor.
In a case when your car has all four heater circuit control codes, you probably don’t need to replace all four O2 sensors. Something else is likely causing the problem, such as an aftermarket remote starter not powering the circuits that turn on the controls.