What it means
The EVAP fuel-vapor temperature sensor signal sits below the lower plausibility limit — short to ground or short between signal and ground inside the sensor.
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 converts vapor temperature into a signal monitored by the control module. P2026 sets when that signal is too low electrically, which can result from a signal wire shorted to ground or a sensor or connector fault pulling it down.
Common causes
Most likely first.
- Short to ground on signal line
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
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
- Check freeze-frame data and live sensor data to confirm the vapor-temperature signal is low or pinned at an implausible value.
- Inspect the sensor connector for corrosion, moisture, damaged insulation, or terminals touching ground.
- Trace the sensor signal wire for chafing or crushed sections that could short it to ground.
- Use the wiring diagram to check for a signal-to-ground short and verify sensor ground and reference circuits against the manufacturer's specifications.
- If the harness is sound, test the sensor separately as specified by the manufacturer to determine whether it is pulling the signal low.
Common fixes
- Clean and secure corroded or loose sensor connector terminals.
- Repair the signal wire where it is shorted to ground or chafed.
- Repair a damaged sensor ground or reference connection.
- Replace the EVAP vapor-temperature sensor if it pulls the signal low despite a sound harness.
Can I keep driving?
The vehicle is generally drivable, but EVAP monitoring may not work correctly and an emissions inspection may fail. If fuel odor is present, avoid flames and address the source 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.