P2401
Evaporative Emission System Leak Detection Pump Control Circuit Low
Get Your FREE AI Diagnostic Report
Enter your vehicle for a personalized diagnosis for code P2401
The P2401 code means the PCM has detected a lower-than-expected voltage in the control circuit for the EVAP leak detection pump. This pump is responsible for testing the fuel vapor recovery system (EVAP system) for leaks by creating pressure or vacuum. A low circuit reading typically indicates an open circuit, high resistance, or a failed pump.
This code will not affect how your vehicle drives day to day. The engine will run normally, acceleration will feel the same, and fuel economy should not change. However, the EVAP system monitoring is disabled, meaning fuel vapor leaks will go undetected. Your vehicle will fail an emissions test, and in some areas this means you cannot renew your registration.
To diagnose this issue, start by checking the electrical connector at the leak detection pump for corrosion, looseness, or damage. Check the EVAP system fuse as well. If those are fine, use a multimeter to verify voltage at the pump connector with the key on. If voltage is present but the pump does not operate, the pump itself needs replacement. The pump is commonly located near the charcoal canister under the vehicle or near the fuel tank.
Severity
Symptoms
- •Check Engine Light is on
- •Vehicle will fail emissions test
- •Possible faint fuel odor near fuel tank
- •No noticeable effect on engine performance
- •Fuel vapor system not being monitored properly
Likely Causes
The leak detection pump has worn out or failed internally, drawing too little current and causing a low circuit reading.
A break in the wiring or a short to ground in the LDP circuit causes the PCM to see abnormally low voltage.
Corrosion or a poor connection at the LDP connector creates high resistance, resulting in a low voltage reading.
A blown fuse will result in zero voltage at the pump, triggering a circuit low condition.
The PCM's output driver for the LDP circuit may be damaged, unable to properly control the pump.
Estimated Cost
Professional Repair
Includes parts + labor
Common Fixes
- Replace EVAP leak detection pump
- Repair or replace damaged wiring and connectors
- Clean corroded electrical connections
- Replace blown fuse
Shop Parts
Videos
Causes and Fixes Toyota P2401 Code: EVAP System Leak Detection Pump Control Circuit Low
HVAC Mechanic
Check Engine Code Says EVAP? How to Diagnose EVAP System Problems and Leaks
1A Auto: Repair Tips & Secrets Only Mechanics Know
HOW TO FIX EVAP CODES FOR GOOD (LARGE/SMALL LEAK DETECTED) P0455 P0456 P0457 P0458 P0459
Top 5 Auto Repairs