P0037

HO2S Heater Control Circuit Low Bank 1 Sensor 2

Emissions / O2 sensor Generic OBD-II Medium

What it means

P0037 means the heater circuit inside the Bank 1, Sensor 2 oxygen sensor — the one after the catalytic converter — is reading low voltage, usually from a failed heater element or a wiring fault. The sensor warms up too slowly to monitor the catalyst properly. It's an emissions fault, not a running problem.

Medium

Can I keep driving? Safe to drive — this is an emissions monitoring fault; you'll have a check-engine light and may fail an emissions test, but performance is unaffected.

Real-world scan data

Seen in

2,521

scans in the past year

Found in

0.4%

of scans

0.7%

of scans that found faults

Appears alongside · share of P0037 scans

P0031in 30.0% of scans

P0300in 15.4% of scans

P0302in 14.1% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Fails or is not ready for an emissions test
Oxygen-sensor heater monitor won't complete
No noticeable change in how the car drives

Common causes

Most likely first

Failed oxygen-sensor heater element (most common — replace the sensor)Likely
Open, shorted, or high-resistance wiring to the sensor heaterCommon
Corroded or loose connector at the sensorCommon
Blown fuse feeding the heater circuitLess often
ECM heater-driver fault (least likely)Less often

How to diagnose & fix

Work through it in order

Check the fuse for the O2 sensor heater circuit.
Inspect the Bank 1 Sensor 2 connector and wiring for damage or corrosion.
Measure the heater resistance at the sensor against spec.
Replace the oxygen sensor if the heater is open or out of spec.
Clear the code and confirm the heater monitor passes.

FAQ

Quick answers

Is it safe to drive with P0037?+

Yes — the car drives normally. The downstream sensor mainly checks the catalytic converter, so the main downside is a check-engine light and a likely emissions-test failure.

Can I just clear P0037?+

You can, but it'll set again once the ECM runs the heater test. Replace the sensor or fix the wiring to clear it for good.

Read & clear P0037 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX