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DTC/P0440·BMW

P0440 on BMW: Causes, Symptoms and Fix Cost

Quick Answer
Low SeveritySafe to drive (short-term)BMW

P0440 on a BMW is the generic OBD-II code for an evaporative emission control system malfunction. It means the ECU detected a fault in the system that captures fuel vapours from the tank and routes them to the engine. The most common trigger is a loose or missing fuel cap, but it can also indicate hose leaks, a failed purge valve, or a cracked charcoal canister.

Typical repair cost, all makes€10 - €600

Connect any standard Bluetooth OBD2 adapter to your BMW and Skanyx tells you what P0440 means on that engine, whether it is safe to keep driving, and what the fix should cost. Free on iPhone and Android.

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What does P0440 mean on a BMW?

The Quick Answer above is the generic definition. What follows is the model-specific detail for the BMW models that log P0440.

BMW 3 Series

2005-2024

BMW uses a leak detection pump (LDP) mounted near the charcoal canister to actively test the EVAP system. A failing LDP is a frequent cause of false P0440 codes on the E90 and F30. The fuel tank vent valve on the E90 is also a known failure point.

What causes P0440 on a BMW?

Beyond the generic causes listed on the main P0440 page, these are the patterns noted for BMW models:

BMW 3 SeriesFailed leak detection pump on E90/F30 triggering false code
BMW 3 SeriesFuel tank vent valve failure

How to diagnose P0440 on a BMW with OBD2

Follow these steps to pinpoint the root cause of P0440:

  1. Check the fuel cap first. Remove it, inspect the rubber seal for cracks or debris, and re-seat it until it clicks. Clear the code and drive for several cycles to see if it returns
  2. Visually inspect EVAP hoses from the fuel tank to the charcoal canister and from the canister to the purge valve at the engine. Look for cracks, brittle plastic, loose clamps, or disconnections
  3. Perform a smoke test on the EVAP system. Seal the system, introduce smoke, and watch for visible plumes escaping at hose connections, the canister, or the fuel tank area. Expect 50 to 120 EUR for the diagnostic alone at a workshop
  4. Check the purge and vent valves: with manufacturer-level software you can command them open and closed and listen for clicking (a generic OBD2 reader cannot run these actuator tests); otherwise test them off the car with 12 V and a hand vacuum pump. A stuck-open or stuck-closed valve is a frequent cause
  5. If the smoke test reveals no external leaks, inspect the charcoal canister for cracks and check the fuel tank pressure sensor reading with live data

How much does P0440 cost to fix on a BMW? (EUR)

Estimated repair costs for P0440 in EUR, compiled across makes. Expect BMW parts and labour towards the upper end of each range.

Repair Parts Cost Labor Cost Total Estimate DIY Difficulty
Replace fuel cap €10–€40 €0–€0 €10–€40 Easy
Replace vent or purge valve €40–€150 €30–€80 €70–€230 Moderate
Replace charcoal canister €100–€400 €80–€200 €180–€600 Professional

Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.

These codes are often seen alongside P0440 or point to related issues, on any make:

Looking for the full P0440 reference (all makes, full diagnosis flow, complete repair cost matrix)?

See the main P0440 guide
Skanyx · BMW

Diagnose P0440 on your BMW

Your car logged P0440. Skanyx reads it on any standard Bluetooth OBD2 adapter, tells you whether it is safe to keep driving, and shows the €10-€600 repair range so you know the number before a shop quotes you. Free on iPhone and Android, and you do not need to be a mechanic to read it.

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