What it means
The control module monitors the signal from engine coolant temperature sensor 2. It sets this code when the circuit signal is above the calibrated range; the code identifies the signal condition, not necessarily a failed sensor.
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 2 provides the control module with a second coolant-temperature signal; its location and function differ across vehicles. P2185 sets when the sensor 2 circuit signal is above its calibrated range, which can be caused by an open sensor element or signal wire as well as a connector fault.
Common causes
Most likely first.
- Sensor element open
- Signal wire open
- 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
- Check freeze-frame and live data to see whether sensor 2 reads implausibly cold compared with sensor 1 and ambient temperature.
- Inspect sensor 2's connector and wiring for a disconnected plug, corrosion, broken wire, or loose terminal.
- Watch sensor 2 live data while gently moving the harness to reveal an intermittent open connection.
- Check the sensor 2 signal path for an open circuit and inspect connector contact quality following the manufacturer's procedure.
- If the circuit is intact, test sensor 2 against the manufacturer's specification and replace it only if it fails.
Common fixes
- Reconnect and secure a loose sensor 2 connector.
- Repair an open or damaged section of sensor 2 wiring.
- Clean or replace corroded connector terminals as appropriate.
- Replace sensor 2 if its element tests open or otherwise fails the manufacturer's specification.
Can I keep driving?
Avoid driving if the cooling fan does not respond properly or the engine temperature rises; stop safely if it overheats. An above-range sensor 2 signal can cause incorrect cooling control and may affect starting or warm-up.
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.