OBD-II Code · Powertrain
P2400
EVAP Leak Detection Pump Control Circuit Open
Severity
low
Lowest on our scale. Fix it when convenient.
Can you drive it
Only if running normally
A short trip to a shop may be reasonable if the light is steady and the car runs normally. Stop safely for a flashing light, severe shaking, overheating, loss of power, or another urgent warning. The code alone cannot confirm safety.
Indicative cost (USD)
$200–$700
Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
Leak detection pump (LDP) circuit open — typically European/Asian EVAP systems.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then work the likely-causes list in the order shown.
That order is what a shop checks first for this code — wiring and connections before the component they run to, because a connector costs nothing to inspect and is a common answer.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Check engine light
- EVAP large-leak code may follow
Likely causes
- Failed LDPMost common
- Wiring open
- Failed PCM driver
Read the full diagnostic procedureP2400 means the ECM is trying to drive the EVAP Leak Detection Pump (LDP) and is seeing an open circuit on the control side — no current draw at all…
P2400 means the ECM is trying to drive the EVAP Leak Detection Pump (LDP) and is seeing an open circuit on the control side — no current draw at all when the driver should be pulling the solenoid down to ground. On a typical platform the LDP control circuit measures 30-80 ohms across the solenoid winding with the connector unplugged (cold), and the ECM should see roughly 0.3-0.8A of current draw when it commands the pump on during the post-shutdown leak test (vehicle off, key out, 5-45 minutes later). The pump motor itself spikes to 0.5-2A momentarily as it builds the test pressure.
Cheapest-first ladder
- pull the LDP connector and visually inspect the pigtail for green corrosion (this is the #1 finding on rear-axle-mounted units), measure pump-side resistance across the two control pins (anything outside 30-80 ohms = bad solenoid/coil), back-probe the connector with the ignition in KOEO and verify 12V on the supply pin (no voltage = blown fuse or open in the power feed from the EVAP relay), then key-on the bidirectional scan-tool LDP activation test and watch for the current reading.
- An expensive misdiagnosis caveat: VW/Audi/Chrysler LDP is mounted in a notorious water-collection point above the rear axle — corrosion at the connector is the #1 root cause, so replace the pigtail before replacing the pump or you will swap a $300 part and have the code back within a week.
Vehicle-specific patterns1998-2009 VW/Audi (Jetta, Passat, Golf, A4, A6) with the rear-axle-mounted LDP is the textbook P2400 ticket — road spray and salt rot the connector p…
- 1998-2009VW/Audi (Jetta, Passat, Golf, A4, A6) with the rear-axle-mounted LDP is the textbook P2400 ticket — road spray and salt rot the connector pins from the inside out, and you can pull the harness boot and find the copper green to the touch.
- 1998-2008Chrysler/Jeep/Dodge (Sebring, Wrangler, Grand Cherokee) use a combined NVLD/LDP unit that's notorious for an internal solenoid coil break — the unit is non-serviceable, but always cut and inspect the pigtail before condemning.
- 1996-2005Mercedes-Benz (W202, W203, W211) integrate the LDP with the charcoal canister assembly under the rear fender liner, and a leaking vent hose dumps water directly onto the connector. Common LDP repair pattern: replace pump + harness pigtail together; standalone pump replacement leaves the same root cause.
Estimated repair$180 to $650.
Look up another code
P2400 — frequently asked
What does a P2400 code mean?
Leak detection pump (LDP) circuit open — typically European/Asian EVAP systems.
What causes a P2400 code?
Common causes: Failed LDP; Wiring open; Failed PCM driver.
What are the symptoms of a P2400 code?
Typical symptoms: Check engine light; EVAP large-leak code may follow.
Is it safe to drive with a P2400 code?
Only if running normally. A short trip to a shop may be reasonable if the light is steady and the car runs normally. Stop safely for a flashing light, severe shaking, overheating, loss of power, or another urgent warning. The code alone cannot confirm safety. Estimated repair: $200-$700.
How do I diagnose a P2400 code?
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed. 1. Note every code that is set, not just this one. 2. Read the freeze frame — the conditions the fault was recorded under. 3. Confirm the fault is current rather than history. 4. Then work the likely-causes list in the order shown.
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