P0440 on BMW: Causes, Symptoms and Fix Cost
Quick Answer
Safe to drive (short-term)
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.
- Severity
- Low · EVAP System
- Typical repair cost, all makes
- €10-€600
Connect a standard OBD2 adapter (Bluetooth LE on iPhone) 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.
Get Skanyx freeWhat 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
2005-2011
On the E90 3 Series, BMW tests the EVAP system with a built-in leak diagnosis pump (DMTL, also called LDP) that pressurises the fuel tank. The pump also holds the tank vent valve and a filter, so a clogged filter or a failed pump can set an EVAP code with no real leak. Check the fuel cap first, then have the pump test run with a BMW-capable scan tool.
Sources
- vehicleservicepros.com vehicleservicepros.com/service-repair/the-garage/article/21183156/diagnosing-bmw
- workshop-manuals.com workshop-manuals.com/bmw/3_series_e90/328i_n51_sal/1_service_information/16__fue
What causes P0440 on a BMW?
Beyond the generic causes listed on the main P0440 page, these are the patterns noted for BMW models:
Faulty leak diagnosis pump (DMTL/LDP) or clogged pump filter
: BMW 3 Series
Loose or worn fuel cap
: BMW 3 Series
How to diagnose P0440 on a BMW with OBD2
- 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
- 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
- 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
- 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
- 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 October 2026. Costs vary by region, vehicle, and shop.
Codes related to P0440
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