P01E4 code meaning
Engine Coolant Temperature Sensor 3 Circuit Range/Performance
Powertrain system Generic code P01xx codes Check engine light
What P01E4 means
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 gasoline 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.
P01E4 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P01E4
- Check engine light on
- Engine warms up slowly, heater output weak
- Often together with cooling system codes
Common causes of P01E4
- Most likelyThermostat not closing fully
- PossibleSensor 3 drifting
- PossibleLow coolant or air at the sensor
- Less likelyContact resistance at the connector
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Engine coolant temperature sensor 3Sensor wiringThermostat
What each part of P01E4 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 1 | Area: fuel and air metering. |
| E4 | The exact fault in that area. |
What to do next
- Note P01E4 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P01E4
What does P01E4 mean?
P01E4 means "Engine Coolant Temperature Sensor 3 Circuit Range/Performance". 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 gasoline engines it sits in the engine block water jacket, on Audi's 3.0 TFSI V6 it is part of the thermal management. It is a generic code, so it means the same on every make.
Is it safe to drive with P01E4?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P01E4 fail an emissions test?
Yes, it can. P01E4 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P01E4 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P01E4 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.