What it means
The ECM detects a circuit high fault on the engine coolant temperature sensor 6. Reading cannot be used reliably for control.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Engine coolant temperature sensor 6 reports coolant temperature to the ECM for engine and cooling-system control. This code sets when its signal is unusually high, which can result from an open sensor or circuit, a signal wire shorted to battery voltage, or poor connector contact.
Common causes
Most likely first.
- Signal wire shorted to B+
- Open sensor
- Connector pins corroded - high contact resistance
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
- Save freeze-frame data and compare sensor 6 live temperature with other coolant-temperature readings and ambient temperature; a value that is implausibly high points to a circuit fault.
- With the engine off and cool, inspect sensor 6, its connector, and nearby wiring for loose or corroded terminals, damage, or a disconnected plug.
- Check the sensor 6 harness for a signal wire contacting a power feed or for an open circuit.
- Use the wiring diagram to test sensor 6 circuit continuity and check for a short to battery voltage, following the manufacturer's procedure.
- If the wiring and connector pass inspection, test sensor 6 against the manufacturer's specification and replace it if it is open or faulty.
Common fixes
- Reconnect sensor 6 or clean and repair its corroded connector terminals.
- Repair an open or damaged sensor 6 wire.
- Repair the signal wire if it is shorted to a power feed.
- Replace engine coolant temperature sensor 6 if it fails testing.
Can I keep driving?
Keep trips short and watch for overheating or abnormal heater and fan behavior; stop if the engine temperature rises or a warning appears. The ECM may be acting on an unreliable temperature reading, which can impair engine operation and allow overheating to go unnoticed.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.