P2404 — Evaporative Emission System Leak Detection Pump Sense Circuit Range/Performance

OBD2 code P2404 flags a problem with the evaporative emission (EVAP) system (evaporative emission system leak detection pump sense circuit range/performance). The car is usually drivable while you plan the repair. Common culprits: faulty purge valve (canister purge solenoid), cracked EVAP hoses or lines, 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 P2404 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 Compare the evaporative emission system leak detection pump sense live reading against a known-good reference (specification or a correlated sensor) under the conditions from the freeze frame.
  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 P2404 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P2404 (parts and labor, USD, independent shop rates): Replace the charcoal canister: $250–$700; Replace the purge or vent valve: $120–$350; Replace the fuel cap: $20–$60. Overall, fixing P2404 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 P2404?

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

How do I diagnose P2404 myself?

Start with a scan: confirm P2404, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the evaporative emission system leak detection pump sense, and verify the suspect component against live data before buying parts.

What are the symptoms of P2404?

Drivers most often notice: Check Engine Light on, slightly worse fuel economy, difficulty refueling (nozzle clicks off), fuel smell near the car, especially after refueling.

Will P2404 clear itself?

Sometimes P2404 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 P2404 mean?

OBD2 code P2404 flags a problem with the evaporative emission (EVAP) system (evaporative emission system leak detection pump sense circuit range/performance). The car is usually drivable while you plan the repair. Common culprits: faulty purge valve (canister purge solenoid), cracked EVAP hoses or lines, small leak in the fuel tank or filler neck.

What does P2404 mean?

When P2404 appears on a scan, it means the control module has flagged a problem in the evaporative emission (EVAP) system: evaporative emission system leak detection pump sense circuit range/performance. The fault sits in the powertrain (engine/transmission) group of the OBD2 standard.

“Range/performance” means the signal from the evaporative emission system leak detection pump sense is electrically valid but does not match what the module expects for current operating conditions. The wiring is usually intact; the problem is a degraded component, a drifted sensor or a mechanical fault upstream.

The module monitors this system continuously while driving. When readings fall outside the expected range for a defined number of drive cycles, it stores P2404 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 P2404

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

What causes P2404?

  • incorrect calibration after a module update or battery disconnect
  • mechanical fault that the sensor correctly reports
  • degraded or drifting evaporative emission system leak detection pump sense
  • cracked EVAP hoses or lines
  • loose, damaged or wrong fuel cap
  • saturated or damaged charcoal canister
  • small leak in the fuel tank or filler neck
  • faulty vent valve or leak detection pump
  • faulty purge valve (canister purge solenoid)

How to diagnose P2404

  1. Connect an OBD2 scanner, confirm P2404 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. Compare the evaporative emission system leak detection pump sense live reading against a known-good reference (specification or a correlated sensor) under the conditions from the freeze frame.
  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 P2404 does not return.

How to fix P2404

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

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

How much does it cost to fix P2404?

Repair cost depends on which component actually failed. Typical scenarios for P2404 (parts and labor, USD, independent shop rates):

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

Overall, fixing P2404 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 P2404?

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.

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