P2402 — EVAP Leak Detection Pump Control Circuit High
Low severityWhat it means
P2402 is stored when the engine control unit sees a fault involving the EVAP leak detection pump circuit. The leak detection pump pressurises the EVAP system so the control unit can test it for leaks; a circuit fault stops that test running. A “high” reading means the signal is pinned near the top of its range — often an open circuit, a lost ground, or a short to voltage.
Common symptoms
- The live reading sits abnormally high or maxed out
- Usually only a check engine light
- EVAP monitor not completing
- Failed emissions inspection
Likely causes
- Open signal or ground wire
- Signal wire shorted to a voltage supply
- A failed leak detection pump
- A wiring, connector or fuse fault
What to check first
- Check for an open circuit or missing ground at the sensor connector
- Command the pump with a scan tool and listen for it run
- Inspect the pump connector and wiring
Can you keep driving?
Safe to drive; it is an emissions fault, but the car will fail an emissions test until repaired.
Frequently asked questions
What is the most common cause of P2402?
The most likely cause is: Open signal or ground wire. Several other faults can set P2402 as well, so confirm the real cause with live data and the checks above before replacing any parts.
Can I just clear P2402 and keep driving?
Clearing P2402 with an OBD2 scanner turns the warning light off, but if the underlying fault has not been repaired the code will usually come back within a few drive cycles. Fix the cause first, then clear the code to confirm the repair worked.
How serious is P2402?
P2402 is a low-severity code. It rarely affects how the car drives, but it is still worth fixing so the engine runs efficiently and passes an emissions test.
Scan, log and diagnose with MechanicAI
Plug a Bluetooth OBD2 adapter into your car and let MechanicAI turn raw data into answers:
- Scan, read and clear fault codes in seconds
- Inspect every sensor with live data
- Create instant logs and automatic trip records
- And above all — analyze it all with AI for the most likely cause and clear next steps.
Related codes
All information, explanations and guidance on this page are general preliminary information only. They are estimates and may be entirely wrong, incomplete or inaccurate, or may not apply to your vehicle at all. Never take any action based on this content alone — do not decide to keep driving, clear codes, replace parts, repair or otherwise work on your vehicle based only on what you read here. In every case, and for any final decision, you must consult qualified technical personnel (a professional mechanic, an authorized service centre or an engineer) and obtain their approval before acting. MechanicAI accepts no liability or responsibility whatsoever for any damage, fault, injury, loss or outcome that may arise — directly or indirectly — from using or relying on this information, for any reason and under any circumstances. By using this page you acknowledge and accept these terms.