What it means
The ECM detects a circuit low 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 measures coolant temperature at the location served by that sensor, and the ECM uses its signal to manage engine and cooling-system operation. This code sets when the sensor 6 signal is pulled unusually low, such as by a signal wire short to ground or an internally shorted sensor, so the ECM cannot rely on that temperature reading.
Common causes
Most likely first.
- Signal wire shorted to ground
- Internal sensor short
- 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
- Record freeze-frame data and compare sensor 6 live temperature with other coolant-temperature readings and ambient temperature; an implausibly low value helps confirm the fault.
- With the engine off and cool, inspect sensor 6 and its connector for corrosion, damaged pins, loose fit, or coolant intrusion.
- Trace sensor 6 wiring for chafing or pinching that could let the signal wire contact ground.
- Using the wiring diagram, check the sensor 6 signal circuit for a short to ground and inspect the connector terminals for excessive contact resistance.
- If the wiring and connector are sound, test sensor 6 against the manufacturer's specification and replace it if it is internally shorted.
Common fixes
- Clean or repair corroded sensor 6 connector terminals and secure the connector.
- Repair the sensor 6 signal wire where it is shorted to ground.
- Replace engine coolant temperature sensor 6 if it fails testing.
Can I keep driving?
Avoid relying on the temperature gauge or continuing to drive if the engine overheats, the heater behaves abnormally, or the cooling fan does not operate when needed. A false temperature reading can disrupt engine control 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.