OBD-II Code P2402 — What It Means & How to Fix It

What it means

P2402 is the high-voltage version of the EVAP leak detection pump circuit fault.
The ECM is seeing higher voltage than expected, which usually points to an open circuit — a broken wire that lets voltage float high.
The car will drive fine, but the EVAP system can't self-test for fuel vapor leaks and the check engine light will stay on.

Affected Models

All vehicles 1996+ with EVAP leak detection pump
Common in Subaru vehicles
Common in some Nissan models
Common in some European vehicles with active EVAP testing

Common Causes

Open circuit — broken wire in the pump control harness
Disconnected or loose pump connector
Internal open in the leak detection pump motor winding
Corroded connector pins preventing current flow
Blown relay or fuse in the EVAP pump circuit

How to Fix It

Check for blown fuses in the EVAP system fuse circuit.

A blown fuse creates an open circuit to the pump — this is the fastest thing to check and cheapest to fix.
Confirm the pump connector is fully seated and not corroded.

A loose or corroded connector creates an intermittent open circuit that causes the ECM to see floating high voltage.
Test continuity of the pump control wire from connector to ECM.

Set your multimeter to continuity mode — a broken wire will give no beep or show infinite resistance.
Measure pump motor resistance — an open (infinite) reading means the pump is bad.

If the harness tests good but the pump itself shows no resistance, the motor winding is broken and the pump must be replaced.
Repair the open wiring or replace the leak detection pump as needed.

After repair, clear the code and run a complete EVAP drive cycle to confirm the pump circuit operates normally.

When to Call a Professional

If connector and fuse checks don't resolve the code, have a mechanic trace the open circuit in the harness.
Diagnosis involves testing wire continuity from the pump all the way back to the ECM connector.
Expect $80–$130 for diagnosis; pump and wiring repair typically costs $50–$200 total.

Frequently Asked Questions

What's the difference between P2400, P2401, and P2402?

P2400 is an open circuit fault.
P2401 means the circuit voltage is too low (short to ground).
P2402 means the circuit voltage is too high (open circuit or short to power).

Does this affect gas mileage?

Not directly.
The pump is only active during EVAP system self-tests, not during normal driving.

Can I clear the code and just drive?

You can clear it, but it will return if not fixed.
The root cause must be repaired for it to stay gone.