OBD-II code · Powertrain (generic)
P0A03 Motor Electronics Coolant Temperature Sensor High Input
Voltage at motor electronics coolant temperature sensor above threshold. The engine coolant temperature sensor feeds warm-up enrichment, fan control and closed-loop entry — a stuck-cold reading keeps the engine in open loop and rich forever.
Is it safe to drive with P0A03?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen sensor circuit
Repair at a glance
- Difficulty
- Shop_only
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1.5–4 h
- Emissions test
- Usually unaffected
- Parts involved
- Motor Electronics Coolant Temperature Sensor, Wiring Harness
Related codes
- P0A00Motor Electronics Coolant Temperature Sensor Circuit
- P0A01Motor Electronics Coolant Temperature Sensor Range/Performance
- P0A02Motor Electronics Coolant Temperature Sensor Low Input
- P0A04Motor Electronics Coolant Temperature Sensor A Circuit Intermittent
- P0A05Motor Electronics Coolant Pump A Control Circuit/Open
- P0A06Motor Electronics Coolant Pump A Control Circuit Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.