P01E4Engine Coolant Temperature Sensor 3 Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- Coolant temperature sensor 3 is a third NTC coolant sensor on engines with thermal management or split cooling circuits; its position is defined by the manufacturer – on Jaguar Land Rover's 2018–2019 Ingenium petrol engines it sits in the engine block water jacket, on Audi's 3.0 TFSI V6 it is part of the thermal management. As with every NTC sensor, a low signal voltage means hot and a high one cold. CARB requires such additional sensors to be monitored from model year 2019 onwards. P01E4 means the signal is electrically valid but implausible. Audi documents it on 2017–2021 3.0 TFSI V6 models together with cooling system, cylinder head temperature and 'engine temperature too low' codes: the cause was a thermostat that did not close fully, and Audi states that replacing the sensor does not fix it.
- What you may notice
- Check engine light on
- Engine warms up slowly, heater output weak
- Often together with cooling system codes
- Likely causes
- LikelyThermostat not closing fully
- PossibleSensor 3 drifting
- PossibleLow coolant or air at the sensor
- RareContact resistance at the connector
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.