OBD-II code · Powertrain (generic)
P01E5 Engine Coolant Temperature Sensor 3 Circuit Low
ECT sensor 3 signal voltage below expected range. 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 P01E5?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySignal wire shorted to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
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
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–1.5 h
- Emissions test
- Likely to fail
- Parts involved
- Ect Sensor 3, Sensor Wiring
Related codes
- P2184Engine Coolant Temperature Sensor 2 Circuit Low
- P2186Engine Coolant Temperature Sensor 2 Circuit Low
- P2AFEEngine Coolant Temperature Sensor 4 Circuit Low
- P2B2DEngine Coolant Temperature Sensor 5 Circuit Low
- P2BB8Engine Coolant Temperature Sensor 6 Circuit Low
- P01E2Cylinder 12 Injection Timing Performance - Over Advanced
- P01E3Engine Coolant Temperature Sensor 3 Circuit
- P01E4Engine Coolant Temperature Sensor 3 Circuit Range/Performance
- P01E6Engine Coolant Temperature Sensor 3 Circuit High
- P01E7Engine Coolant Temperature Sensor 3 Circuit Intermittent/Erratic
- P01E8Engine Coolant Heater A Control Circuit/Open
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.