P2027 — Evaporative Emissions (EVAP) Fuel Vapor Temperature Sensor Circuit High Voltage

P2027 — Evaporative Emissions (EVAP) Fuel Vapor Temperature Sensor Circuit High Voltage. A fault in the evaporative emission (EVAP) system. The car is usually drivable while you plan the repair. Typical causes: faulty vent valve or leak detection pump, faulty purge valve (canister purge solenoid), small leak in the fuel tank or filler neck.

powertrain (engine/transmission)

Is it safe to drive?

Short-term driving is OK Safe to drive. EVAP faults affect emissions, not drivability — you can keep using the car while planning the repair. Fuel vapour smell is a reason to fix it sooner: vapours are flammable and harmful.

How to diagnose with an OBD scanner

  1. Read the code and freeze frame Connect an OBD2 scanner, confirm P2027 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the evaporative emission (EVAP) system for damage, corrosion, chafing or poor contact.
  4. Subsystem check Check the fuel cap first — it is the most common cause; inspect the seal and tighten until it clicks.
  5. Subsystem check Run an EVAP leak test (smoke test) to locate small leaks in hoses, canister and valves.
  6. Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2027 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P2027 (parts and labor, USD, independent shop rates): Replace the charcoal canister: $250–$700; Replace the fuel cap: $20–$60; Replace the purge or vent valve: $120–$350. Overall, fixing P2027 usually costs between $20 and $700. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

How much does it cost to fix P2027?

Replace the charcoal canister — $250–$700; Replace the fuel cap — $20–$60; Replace the purge or vent valve — $120–$350. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

What is the most common cause of P2027?

The most common causes are: faulty vent valve or leak detection pump, faulty purge valve (canister purge solenoid), small leak in the fuel tank or filler neck.

How do I diagnose P2027 myself?

Start with a scan: confirm P2027, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the evaporative emission (EVAP) system, and verify the suspect component against live data before buying parts.

What are the symptoms of P2027?

Drivers most often notice: difficulty refueling (nozzle clicks off), slightly worse fuel economy, fuel smell near the car, especially after refueling, no noticeable driving symptoms in most cases.

Will P2027 clear itself?

Sometimes P2027 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

What does P2027 mean?

When P2027 appears on a scan, it means the control module has flagged a problem in the evaporative emission (EVAP) system: evaporative emissions (EVAP) fuel vapor temperature sensor circuit high voltage. The fault sits in the powertrain (engine/transmission) group of the OBD2 standard.

The module monitors this system continuously while driving. When readings fall outside the expected range for a defined number of drive cycles, it stores P2027 and switches on the warning light. Freeze frame data saved with the code shows the exact conditions — rpm, load, temperature, speed — at the moment the fault was detected, which is the best starting point for diagnosis.

Common symptoms of P2027

  • difficulty refueling (nozzle clicks off)
  • slightly worse fuel economy
  • fuel smell near the car, especially after refueling
  • no noticeable driving symptoms in most cases
  • Check Engine Light on

What causes P2027?

  • small leak in the fuel tank or filler neck
  • cracked EVAP hoses or lines
  • saturated or damaged charcoal canister
  • faulty purge valve (canister purge solenoid)
  • faulty vent valve or leak detection pump

How to diagnose P2027

  1. Connect an OBD2 scanner, confirm P2027 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Visually inspect the wiring harness and connectors related to the evaporative emission (EVAP) system for damage, corrosion, chafing or poor contact.
  4. Check the fuel cap first — it is the most common cause; inspect the seal and tighten until it clicks.
  5. Run an EVAP leak test (smoke test) to locate small leaks in hoses, canister and valves.
  6. Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2027 does not return.

How to fix P2027

Start with the cheapest and most common causes before replacing expensive parts:

  • Replace the charcoal canister — $250–$700
  • Replace the fuel cap — $20–$60
  • Replace the purge or vent valve — $120–$350

How much does it cost to fix P2027?

Repair cost depends on which component actually failed. Typical scenarios for P2027 (parts and labor, USD, independent shop rates):

  • Replace the charcoal canister: $250–$700
  • Replace the fuel cap: $20–$60
  • Replace the purge or vent valve: $120–$350

Overall, fixing P2027 usually costs between $20 and $700. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Can you drive with P2027?

Safe to drive. EVAP faults affect emissions, not drivability — you can keep using the car while planning the repair. Fuel vapour smell is a reason to fix it sooner: vapours are flammable and harmful.

Related OBD2 codes