P2400
Evaporative Emission System Leak Detection Pump Control Circuit
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The P2400 code indicates a general malfunction in the control circuit for the EVAP (Evaporative Emission System) leak detection pump. This pump is used by your vehicle's computer to pressurize or create a vacuum in the EVAP system to check for fuel vapor leaks. When the PCM detects a problem with the pump's control circuit, it sets this code.
The good news is that this code almost never causes any drivability issues. Your car will run and drive normally. The bad news is that it means your vehicle's emission control system is not working properly, and you will fail an emissions inspection. You may occasionally notice a faint gasoline smell near the rear of the vehicle, particularly after filling up.
Start by checking the simplest things first — make sure your gas cap is tight and in good condition. If the cap is fine, check the fuse for the EVAP system. The leak detection pump itself is the most common failure point and typically costs $50–$150 for the part. It is usually located near the fuel tank or charcoal canister. Replacement difficulty varies by vehicle — some are easily accessible while others require dropping the fuel tank, which may warrant professional help.
Severity
Symptoms
- •Check Engine Light is on
- •Vehicle may fail emissions testing
- •Faint fuel odor near gas tank area
- •No noticeable drivability issues
- •Fuel gauge readings may be slightly erratic
Likely Causes
The leak detection pump (LDP) motor or internal mechanism has failed, preventing it from pressurizing the EVAP system for testing.
Damaged, corroded, or disconnected wiring between the PCM and the leak detection pump causes a circuit malfunction.
A blown fuse in the EVAP circuit will prevent the leak detection pump from operating.
A loose, cracked, or missing gas cap can cause the EVAP system to fail its leak test, triggering the pump circuit code.
In rare cases, the PCM driver circuit for the leak detection pump may have failed internally.
Estimated Cost
Professional Repair
Includes parts + labor
Common Fixes
- Replace EVAP leak detection pump
- Repair or replace damaged wiring and connectors
- Replace blown fuse
- Tighten or replace gas cap
- Clear codes and retest