PCV Heater A Control Circuit High
What it means
P053C means the ECM sees an abnormally high voltage on the positive crankcase ventilation (PCV) heater control circuit. The PCV heater warms the crankcase-vent path to stop it icing up in cold weather. This is an electrical circuit fault — usually the wiring, connector, or heater element — not an engine-performance problem. The car drives normally; the main concern is vent icing in freezing conditions, so fix it to clear the light.
Can I keep driving? Yes — the car drives normally. The PCV heater prevents crankcase-vent icing in cold weather, so the main risk is in freezing conditions; still worth fixing to clear the light.
Common symptoms
What you'll notice
- Check-engine light on
- Usually no change in how the car drives
- In very cold weather, risk of PCV/crankcase-vent icing if the heater isn't working
Common causes
Most likely first
- Open or short to ground in the PCV heater control circuitLikely
- Open or short in the ignition (START/RUN) feed to the heaterCommon
- Faulty PCV heater assemblyCommon
- Corroded or loose connector at the PCV heaterLess often
- Faulty ECM/PCM (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data to confirm the fault is a high-voltage condition on the PCV heater circuit.
- Inspect the PCV heater connector and wiring for opens, shorts, and corrosion.
- Check the ignition (START/RUN) supply and ground for the heater circuit.
- Test the PCV heater element's resistance against spec.
- Repair wiring faults or replace the PCV heater assembly. Clear the code and re-test.
FAQ
Quick answers
Is it safe to drive with P053C?+
Can I just clear P053C?+
Related codes
Often seen with P053C
Read & clear P053C yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.