P2404: EVAP System Leak Detection Pump Sense Circuit Range/Performance

P2404 is a plausibility code: the pump feedback is electrically present but does not behave as the leak test expects. VW's 2014 Golf data book sets it when the sense signal stays high for more than 30.4 s (12 s on another engine) over 30 checks, or when high signal time during pumping adds up to more than 10 s. Subaru has issued a series of bulletins since 2023 (09-102-23 to 09-131-25, many models) because condensation in the ELCM can trigger P2404 falsely; the fix is a leak test, a 35-minute ELCM pump active test and new ECM software. For the 2011-2014 Touareg 3.6, VW linked P2404 to coolant in the pump's vacuum line, and Land Rover lists P2404 with failure types 29 and 2F. P2403 covers a dead feedback, P2407 an unstable one.

Symptoms

• Check engine light, often returning after clearing
• EVAP readiness not set

Most likely causes

• Condensation inside the leak check module (Subaru ELCM, software update available)
• Worn or sticking pump that no longer reaches its expected state in time
• Coolant or debris in the pump's vacuum or vent line

What to check, in order

Start with the simplest. You can tick off each step.

1. Start with the fuel cap: tighten it fully and check its seal
2. Compare the reading with other engine data while varying the engine speed.
3. Inspect the hoses and connections around the tank and the charcoal canister
4. Use the scanner to test the purge and vent solenoid valves
5. Run a smoke test to find small leaks

Good to know

• Repair difficulty: medium
• It affects emissions.

What each character of P2404 means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 4: Emissions
• 04: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2404?

Yes, you can normally keep driving. If there is a strong smell of gasoline, find the leak before continuing and do not smoke nearby.

What causes code P2404?

The most common causes are: condensation inside the leak check module (Subaru ELCM, software update available); worn or sticking pump that no longer reaches its expected state in time; coolant or debris in the pump's vacuum or vent line.

Related codes

• P2403EVAP System Leak Detection Pump Sense Circuit/Open
• P2407EVAP System Leak Detection Pump Sense Circuit Intermittent/Erratic
• P24B9EVAP System Leak Detection Pump Pressure Sensor Circuit Range/Performance
• P0442EVAP System Leak Detected (small leak)

Sources

• static.nhtsa.gov: MC 10073689 2280
• static.nhtsa.gov: MC 11017434 0001
• static.nhtsa.gov: MC 10238463 0001
• static.nhtsa.gov: MC 10157825 9999

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.