P0537
A/C Evaporator Temperature Sensor Circuit Low
A/C & climate control
Generic OBD-II
Low
What it means
P0537 means the ECM or HVAC module sees an abnormally low voltage from the A/C evaporator temperature sensor circuit. That sensor keeps the evaporator from freezing and helps cycle the compressor, so a faulty signal typically shows up as poor cooling or a compressor that won't engage — usually a wiring short, a failed sensor, or a bad connector. It has no effect on how the engine runs.
Low
Can I keep driving? Fully drivable — this only affects the air conditioning; the engine runs normally.
Common symptoms
What you'll notice
- A/C cools poorly or cycles incorrectly
- A/C compressor may not engage
- Evaporator can ice up or airflow drops
- Check-engine or A/C indicator light on
Common causes
Most likely first
- Short to ground in the evaporator temperature sensor wiringLikely
- Faulty A/C evaporator temperature sensorCommon
- Corroded or loose sensor connectorCommon
- Open or short in the sensor signal circuitLess often
- HVAC control module fault (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and inspect the evaporator temperature sensor connector and wiring for a short to ground or corrosion.
- Measure the sensor's resistance and signal voltage against specification.
- Replace the evaporator temperature sensor if it reads out of range with good wiring.
- Clear the code and verify the A/C cycles and cools normally.
FAQ
Quick answers
Is it safe to drive with P0537?+
Yes. This code only affects the air-conditioning system, not the engine or how the car drives. It's a comfort issue rather than a safety one.
Can I just clear P0537?+
It returns if the sensor or its wiring is still faulty. Diagnose the low-voltage circuit before clearing.
Related codes
Often seen with P0537
Read & clear P0537 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