P01E6: Engine Coolant Temperature Sensor 3 Circuit High

What it means

Engine coolant temperature sensor 3 is reporting a signal above its expected range. The code does not specify the sensor's location or function; these depend on the vehicle.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

Coolant temperature sensor 3 sends a signal to a control module, which checks the circuit for a valid temperature reading. This code sets when the signal is higher than the expected electrical range, which can happen if the signal path is open or shorted to a supply; sensor 3's location varies by vehicle.

Common causes

Most likely first.

1. Signal wire open
2. Connector pins corroded - high contact resistance
3. Supply wire pinched against B+ source

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

How to diagnose it

1. Record freeze-frame data and compare sensor 3's reading with other coolant-temperature data and ambient temperature when the engine is cold.
2. Locate sensor 3 and inspect its wiring for breaks, loose connections, or contact with a power source.
3. Check connector terminals for corrosion, pushed-back pins, or poor contact.
4. Test the sensor 3 signal circuit for an open or short to supply and verify its supply and ground using the manufacturer's circuit information.
5. If the circuit checks out, test sensor 3 against the manufacturer's specification.

Common fixes

• Reconnect a loose sensor 3 connector or repair damaged terminals.
• Repair an open in the sensor 3 signal wire.
• Repair wiring shorted to a supply voltage.
• Replace coolant temperature sensor 3 if it fails testing.

Can I keep driving?

Because a high sensor 3 signal may affect cooling fan or warm-up control, watch the temperature gauge and fan operation while driving. Stop if the engine overheats or the fan fails to operate when needed.