P01E4 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 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.

Likely causes

Symptoms

• Check engine light on
• Engine warms up slowly, heater output weak
• Often together with cooling system codes

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: law.cornell.edu, static.nhtsa.gov, static.nhtsa.gov.