P2238 OBD-II Trouble Code: O2 Sensor Positive Current Control Circuit Low Bank 1 Sensor 1

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE P2238 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P2238 code

P2238 is a diagnostic trouble code (DTC) for "O2 Sensor Positive Current Control Circuit Low 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 P2238 DIAGNOSTIC Get a fair and transparent estimate upfront

What the P2238 code means?

P2238 is an OBD-II generic code for the engine control module (ECM) detecting the O2 sensor for bank 1 sensor 1 has a short circuit for the heater control circuit of the O2 sensor.

What causes the P2238 code?

  • The O2 sensor has an short circuit in the heater circuit internal of the sensor.

  • The wiring or connector for the O2 sensor has an short circuit or corrosion in the connections.

  • The heater power relay is shorted to the O2 sensor circuit ground.

What are the symptoms of the P2238 code?

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

  • The ECM will turn off the Check Engine light if three drive cycles pass without another failure.

  • The ECM may go into failure mode fuel control on most manufacturer vehicles. The ECM will go into open loop fuel control on some vehicles and not failure mode.

  • The engine may have different drivability symptoms depending on the manufacture failure mode controls or open loop fuel control.

How does a mechanic diagnose the P2238 code?

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

  • Checks the O2 sensor heater circuit compared to the other O2 sensors to be the same voltage input and control voltages.

  • Checks the O2 heater circuit for open or short circuits in the sensor and relay.

  • Tests the O2 sensor wiring is not shorted to the power relay or ground.

  • Checks the wiring harness for shorts or open circuits from the O2 sensor to the ECM.

Common mistakes when diagnosing the P2238 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 verify the failure before replacing the O2 sensor

  • Replacing all the O2 sensors when the short is in the wiring

How serious is the P2238 code?

Code P2238 is a code indicating the O2 sensor heater circuit is shorted causing the circuit voltage control to be low. This will cause the fuel feedback control to not work and the ECM to put the engine into failure mode or open loop fuel control. This will also cause the vehicle to fail emissions testing.

What repairs can fix the P2238 code?

  • Replace the O2 sensor for an short circuit in the heater circuit.

  • Repair the wiring connector or wiring to the O2 sensor for shorts.

  • Replace the power relay for the heater circuit due to a burned out or shorted circuit that the pinpoint test indicated.

  • Replace the ECM if shorted harness or sensor damaged the ECM.

Additional comments for consideration regarding the P2238 code

Code P2238 is caused most commonly from an internal failure of the heater circuit inside the O2 sensor. The O2 sensor wiring cover is also a vent on some O2 sensors and if the cover is cut or removed then the sensor can get water into the back side of the sensor and cause it to short out the heater circuit and blow the O2 sensor heater circuit fuse or the relay to burn out. Note this if the fuse keeps blowing out when it is replaced. Check all the sensors for intact coverings.

Need help with a P2238 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.

P2238
trouble codes
Check Engine Light

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE P2238 DIAGNOSTIC
Get a fair and transparent estimate upfront

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

4,847

Rating Summary
4,460
187
48
28
124
4,460
187
48
28
124

Omar

10 years of experience
279 reviews
Omar
10 years of experience
Toyota Camry - Check Engine Light is on - Fort Lauderdale, Florida
Omar arrived right on time. He was thorough in running through all of the points of the inspection, and when he found the cause of the check engine light, he explained it in detail. Thankfully, it was a minor issue and easy remedy. He noticed a few things that I needed to pay attention to and sent me an estimate for them. He was friendly, polite, and knowledgeable. I would recommend him highly.

Xavier

9 years of experience
11 reviews
Xavier
9 years of experience
BMW 530i - Check Engine Light is on - Frisco, Texas
Xavier explained all my car’s issues in detail and explained why I was likely having the issues I was having with it, he also explained his suggested next steps and showed me exactly where the problems were on my vehicle. I’ll definitely book him again!

Jerry

6 years of experience
128 reviews
Jerry
6 years of experience
Toyota Sienna - Check Engine Light is on - Lawrenceville, Georgia
Great Mechanic, really knows his stuff. He was kind and explained everything that was potentially wrong with the vehical. Awesome person, you feel you can really trust. Tries to save you $$$, would recommend and book again for any future problems.

John

17 years of experience
137 reviews
John
17 years of experience
BMW 325xi - Check Engine Light is on - Georgetown, Texas
John showed up on time and was very courteous and professional. After reviewing our car gave us an honest assessment of what it would take to fix the car and other fixes to avoid future problems.

More related articles

B1898 OBD-II Trouble Code: Chime Input #2 Circuit Short to Ground
B1898 means there is a circuit issue with chime input 2, most likely due to a damaged electrical component.
B1212 OBD-II Trouble Code: EIC Switch-2 Assembly Circuit Short To Ground
B1212 means a short circuit has been detected in the dashboard EIC, possibly due to wiring issues or a blown fuse.
P2231 OBD-II Trouble Code: O2 Sensor Signal Circuit Shorted to Heater Circuit Bank 1 Sensor 1
P2231 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...

Related questions

P2097 trouble code - 2012 Chevrolet Captiva Sport

Hi there. For your vehicle's P2097 (post catalyst fuel trim system too rich bank 1) code, this can be difficult to diagnose. For all intents and purposes, the vehicle's PCM (powertrain control module) has recognized too much fuel and not...

Check Engine light coming on.

I would have the check engine light inspected by a YourMechanic Technician, They can pull codes off the computer and determine what is malfunctioning.

I just had a diagnostic performed on my car and the following error code came up P0299 boost control sensor.

Hi there. Check to see what the oil pressure is in the engine. If the oil pressure is low, then the P0299 code can appear. Also, check for the EGR operation and see if its sticking. A faulty EGR will...

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.

1-800-701-6230 · hi@yourmechanic.com