Engine Coolant Temperature Sensor 2 Circuit Low
What it means
P2184 means the ECM sees an abnormally low voltage from the second engine coolant temperature sensor, usually from a wiring short to ground or a failed sensor. It's a signal fault rather than a real overheating event, so the car still drives, but the ECM may lean on a default value that nudges fan and fueling behavior until it's corrected.
Can I keep driving? Safe to drive — it's a sensor-signal fault. The engine runs, though cooling-fan or fueling behavior may be slightly off until it's fixed.
Real-world scan data
Appears alongside · share of P2184 scans
Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.
Common symptoms
What you'll notice
- Check-engine light on
- Inaccurate coolant temperature reading
- Cooling fans running more than usual or fueling slightly off
- Often no obvious change in how the car drives
Common causes
Most likely first
- Signal wire shorted to ground (drives the voltage low)Likely
- Faulty engine coolant temperature sensor 2Common
- Poor connection or corrosion at the sensor connectorCommon
- Chafed or damaged sensor harnessLess often
- Rarely, a faulty ECM/PCMLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check the sensor 2 temperature reading for an implausible value.
- Inspect the connector and harness for a short to ground, corrosion, or damage.
- Backprobe the sensor (key on, engine off) for the expected reference voltage and a clean ground.
- Compare sensor 2 resistance against spec at a known temperature.
- If the wiring is good but the sensor is out of range, replace it and retest.
FAQ
Quick answers
Is it safe to drive with P2184?+
Can I just clear P2184?+
Related codes
Read & clear P2184 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.