EVAP Fuel Vapor Temperature Sensor Circuit High Voltage
The P2027 code indicates that the Powertrain Control Module (PCM) has detected a voltage signal from the Evaporative Emission (EVAP) fuel vapor temperature sensor that is higher than the expected range. This sensor monitors the temperature of fuel vapors in the EVAP system to help control purge flow. High voltage typically points to a short circuit to power, a faulty sensor, or a wiring issue. The EVAP system is part of the vehicle's emissions control, and this fault can affect fuel trim and emissions.
1. Most Common Causes
- Faulty EVAP fuel vapor temperature sensor
- Short circuit to battery voltage in sensor wiring
- Open or high resistance in sensor ground circuit
- Corroded or damaged connector at sensor
- Failed PCM (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Possible rough idle or hesitation
- Failed emissions test
- Fuel odor from engine bay
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm P2027 and check for related EVAP codes.
Step 2: Visually inspect the EVAP temperature sensor connector and wiring for damage, corrosion, or shorts.
Step 3: Disconnect the sensor and measure voltage at the harness connector with key on; should be 5V reference. If higher than 5V, repair short to power.
Step 4: Test sensor resistance with a multimeter; compare to manufacturer specs (typically 2-10 kΩ at room temperature). Replace if out of range.
Step 5: If wiring and sensor are good, suspect PCM fault; perform PCM voltage output test or consult dealer.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, but the Check Engine Light will be on and the vehicle may fail an emissions test. The EVAP system is not critical for engine operation, but a faulty sensor can affect fuel trim and drivability over time.
How much does it cost to fix?▼
Typically $50-$150 for parts and labor. The sensor itself costs $20-$60, and labor is about $30-$90 depending on vehicle accessibility.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.