OBD-II code · Powertrain (generic)
P01F8 Engine Coolant Heater A Control Circuit Driver Current/Temperature Too High
Engine Coolant Heater A Control Circuit Driver Current/Temperature Too High: the component is overheating, typically from extended load or slip.
Is it safe to drive with P01F8?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyShort circuit in heater wiring or element
Symptoms
- Check engine light on
- Cooling fan runs constantly or not at all
- Cabin heater weak or excessively hot
- Possible long warm-up time or hard cold start
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–3 h
- Emissions test
- Likely to fail
- Parts involved
- Coolant Heater A, Heater Driver
Related codes
- P01F9Engine Coolant Heater B Control Circuit Driver Current/Temperature Too High
- P01F5O2 Sensor Circuit No Activity Detected Bank 1 Sensor 4
- P01F6O2 Sensor Signal Biased/Stuck Lean Bank 1 Sensor 4
- P01F7O2 Sensor Signal Biased/Stuck Rich Bank 1 Sensor 4
- P01FATurbocharger Outlet Pressure Sensor B Circuit
- P01FBTurbocharger Outlet Pressure Sensor B Range/Performance
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.