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.
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.
Related codes
Often seen with P0037
Read & clear P0037 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX