What it means
The EVAP fuel-vapor temperature sensor signal sits above the upper plausibility limit — open signal line, broken sensor, or short to B+.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The EVAP fuel-vapor temperature sensor sends a temperature-dependent signal to the control module. P2027 sets when the signal voltage is too high, commonly because the signal circuit is open or the sensor or wiring no longer pulls the signal into its expected range.
Common causes
Most likely first.
- Open signal line
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
How to diagnose it
- Review freeze-frame data and live sensor data to confirm the vapor-temperature signal is high or fixed at an implausible value.
- Inspect the sensor connector for a loose or backed-out terminal, corrosion, moisture, or a broken wire near the plug.
- Trace the signal circuit for an open conductor or damage that could connect it to battery voltage.
- Check signal continuity, shorts to power, and sensor supply and ground using the manufacturer's wiring diagram and specifications.
- If the wiring passes, test the EVAP vapor-temperature sensor using the manufacturer's procedure.
Common fixes
- Reseat a backed-out terminal and secure the sensor connector.
- Repair an open signal wire or damaged connector.
- Repair wiring shorted to a power source.
- Replace the sensor if its output remains too high with correct wiring and connections.
Can I keep driving?
The vehicle will usually remain drivable, though EVAP monitoring can be disabled and emissions testing may fail. If you notice fuel odor, avoid ignition sources and have the leak risk checked promptly.
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.