P2231 OBD-II Trouble Code: O2 Sensor Signal Circuit Shorted to Heater Circuit Bank 1 Sensor 1

Our certified mechanics come to you · Get a fair and transparent estimate upfront

Red-stars EXCELLENT RATING ON

Cost of diagnosing the P2231 code

P2231 is a diagnostic trouble code (DTC) for "O2 Sensor Signal Circuit Shorted to Heater Circuit Bank 1 Sensor 1". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$20.00
Toyota$20.00
BMW$20.00
SCHEDULE P2231 DIAGNOSTIC Get a fair and transparent estimate upfront

P2231 code definition

O2 Sensor Signal Circuit Shorted to Heater Circuit Bank 1 Sensor 1

What the P2231 code means

P2231 is an OBD-II generic code for the engine control module (ECM) detecting the O2 sensor signal is shorted to the heater circuit on bank 1 sensor 1.

What causes the P2231 code?

  • The engine control module (ECM) monitors the O2 sensor bank 1 sensor 1 signal wire and is expecting only about 1.2 volts maximum. When the ECM sees a return voltage above 1.2 volts, it knows the sensor is shorted to the heater circuit that is running battery voltage. When it sees the short, the ECM turns on the Check Engine Light and the P2231 code is set.

  • The O2 sensor is shorted internally or the wiring is shorted.

What are the symptoms of the P2231 code?

  • The Check Engine Light will be illuminated and the code is set in the ECM memory as a fault.

  • The ECM will ignore the O2 sensor and use all the other O2 sensors to try and control the fuel or it will go into open loop fuel control.

  • The engine may hesitate on acceleration.

  • The fuel mileage may be more than before failure.

How does a mechanic diagnose the P2231 code?

  • Scans for codes and documents any codes in the ECM, then looks at the freeze frame data for failure.

  • Monitors the O2 sensors for bank 1 sensor 1 to see if the signal is shorted to the heater circuit.

  • Inspects the O2 sensor and the wire harness for any damage that could cause the short.

  • Follows the manufacturer pinpoint tests for the diagnosis and replacement of the O2 sensor if the O2 sensor is internally shorted.

Common mistakes when diagnosing the P2231 code

  • Clearing ECM memory codes before checking the freeze frame data for the main failure problem, so the failure may be duplicated and repaired.

  • Failing to clear the ECM codes after the codes are fixed so the ECM will enable the system to control the fuel again.

How serious is the P2231 code?

Code P2231 is a code indicating the engine cannot control the fuel since it cannot go into a closed loop on bank 1. This will cause the engine to fail emissions testing and the engine to not run as efficient as it can.

What repairs can fix the P2231 code?

Additional comments for consideration regarding the P2231 code

Code P2231 is for a short in the bank 1 sensor 1 O2 sensor. The most common problems that cause this are issues with the sensor wiring or the sensor being contaminated by an oil leak. The short can also be from a harness that comes loose and melts on the exhaust. The sensor shorting is that last problem to look for. If an oil leak is the cause of the problem, then make sure you replace the O2 sensor and repair the oil leak so the problem will not happen again anytime soon.

Need help with a P2231 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

P2231
trouble codes
Check Engine Light

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P2231 code.

SCHEDULE P2231 DIAGNOSTIC
Get a $20 credit for the follow-up repair

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.8/5

Number of Reviews

5,395

Rating Summary
4,978
202
50
30
135
4,978
202
50
30
135

Anthony

6 years of experience
18 reviews
Anthony
6 years of experience
Jeep Grand Cherokee - Check Engine Light is on - Carmichael, California
Anthony was great! We are very happy that we chose to go with this company instead of the overpriced and slow service we get from the Jeep dealership. He was on time and did the job just as expected. He identified a couple of other things that need to be done before the problems get worse. We appreciate having a technician give us direct feedback regarding our vehicle, rather than a service advisor (salesperson) that we've had to deal with in the past at the dealership. We'll be booking the addtional services very soon and will definitely request Anthony again now that he is familiar with our vehicle!

Michael

37 years of experience
113 reviews
Michael
37 years of experience
Subaru Forester - Check Engine Light is on - Santa Fe Springs, California
Michael was punctual and courteous. He knows what he’s doing and I would absolutely recommend him to anyone.

Anthony

6 years of experience
18 reviews
Anthony
6 years of experience
BMW 740Li - Check Engine Light is on - Roseville, California
Very helpful in finding out the fault codes in my bmw 740 li. It was simple fix and that the two tube hose just had to be connected and my drive train malfunction went away. This saved me from having to go the an expensive dealership. Anthony has a good attitude about his work.

Breck

19 years of experience
613 reviews
Breck
19 years of experience
Ram 1500 - Check Engine Light is on - Houston, Texas
Breck did a great job working on my truck. Showed up on time, found any issues I had on my truck and explained everything to me so that I understood what was going on. Went above and beyond, definitely will book him for future appointments.


More related articles

P0468 OBD-II Trouble Code: EVAP Control System Malfunction
P0468 P0468 code definition The P0468 code is defined as Purge Flow Sensor Circuit High Input. Co-existing OBD-II codes may include P0440 or P0442, often indicating a loose gas cap, or P0443 through P0449, which can indicate an EVAP Purge...
P0456 OBD-II Trouble Code: Evaporative Emissions System Small Leak Detected
P0456 code definition Evaporative Emissions System Small Leak Detected What the P0456 code means P0456 is an OBD-II generic code that the...
P0787 OBD-II Trouble Code: Shift/Timing Solenoid Low
P0787 means there is a problem with the shift/timing solenoid which may cause the transmission to not shift out of gear or have harsh shifting.

Related questions

Massive hesitation between 1-2 shifting and nearly dies occassionally at stop.

Hi there. It seems that the EGR (Exhaust Gas Recirculation) Valve is stuck and not allowing the engine to run good causing the engine to hesitate, especially when shifting. Take the EGR off and clean it. Then put it back...

Car isn't shifting when pedal is all the way down and is slow.

Your engine management system is going into "limp mode" when the Check Engine light is illuminated, reducing engine power, and quite likely, leaving your automatic transmission in 2nd gear. This is why you are experiencing greatly diminished performance. Turning your...

Car lost power and a cylinder.

The check engine light came on as a warning your vehicle is in need of service. The most likely cause is the engine is misfiring from an ignition coil failure or the plug wires got oil on them. I recommend...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com