P240C — Evaporative Emission System Leak Detection Pump Heater Control Circuit High

P240C — Evaporative Emission System Leak Detection Pump Heater Control Circuit High. A fault in the evaporative emission (EVAP) system. The car is usually drivable while you plan the repair. Typical causes: faulty purge valve (canister purge solenoid), saturated or damaged charcoal canister, 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 P240C 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 With the evaporative emission system leak detection pump heater control disconnected, measure signal voltage at the harness connector: a high reading with the component unplugged indicates a short to power in the harness; if it drops to normal, the component itself is faulty.
  5. Subsystem check Check the fuel cap first — it is the most common cause; inspect the seal and tighten until it clicks.
  6. Subsystem check Run an EVAP leak test (smoke test) to locate small leaks in hoses, canister and valves.
  7. Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P240C does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P240C (parts and labor, USD, independent shop rates): Replace the purge or vent valve: $120–$350; Replace the fuel cap: $20–$60; Replace the charcoal canister: $250–$700. Overall, fixing P240C 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

What is the most common cause of P240C?

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

How do I diagnose P240C myself?

Start with a scan: confirm P240C, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the evaporative emission system leak detection pump heater control, and verify the suspect component against live data before buying parts.

Will P240C clear itself?

Sometimes P240C 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 OBD2 code P240C mean?

P240C — Evaporative Emission System Leak Detection Pump Heater Control Circuit High. A fault in the evaporative emission (EVAP) system. The car is usually drivable while you plan the repair. Typical causes: faulty purge valve (canister purge solenoid), saturated or damaged charcoal canister, small leak in the fuel tank or filler neck.

How much does it cost to fix P240C?

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

What does P240C mean?

P240C is logged by the onboard diagnostics when the evaporative emission (EVAP) system does not behave as expected. The official definition is “Evaporative Emission System Leak Detection Pump Heater Control Circuit High”. This is a powertrain (engine/transmission) category code.

“Circuit high” means the control module sees a voltage on the evaporative emission system leak detection pump heater control circuit that is above the expected range — typically close to battery voltage. Physically this points to a short to a power feed, a broken ground return, or a failed component pulling the signal line high.

This code does not appear from a single bad reading: the module must see the fault condition repeat under defined operating conditions before it turns on the warning light. The freeze frame captured with P240C — engine load, rpm, temperature, speed — tells you exactly when the problem occurs, so reproduce those conditions when testing.

Common symptoms of P240C

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

What causes P240C?

  • failed evaporative emission system leak detection pump heater control pulling the signal high
  • signal wire shorted to battery positive
  • open ground return of the evaporative emission system leak detection pump heater control
  • small leak in the fuel tank or filler neck
  • faulty purge valve (canister purge solenoid)
  • saturated or damaged charcoal canister
  • cracked EVAP hoses or lines

How to diagnose P240C

  1. Connect an OBD2 scanner, confirm P240C 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. With the evaporative emission system leak detection pump heater control disconnected, measure signal voltage at the harness connector: a high reading with the component unplugged indicates a short to power in the harness; if it drops to normal, the component itself is faulty.
  5. Check the fuel cap first — it is the most common cause; inspect the seal and tighten until it clicks.
  6. Run an EVAP leak test (smoke test) to locate small leaks in hoses, canister and valves.
  7. Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P240C does not return.

How to fix P240C

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

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

How much does it cost to fix P240C?

Repair cost depends on which component actually failed. Typical scenarios for P240C (parts and labor, USD, independent shop rates):

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

Overall, fixing P240C 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 P240C?

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