P1440 — 9 documented meanings by make

P1440 does not mean the same thing on every car — manufacturers reuse the number for different faults. 15 makes document it: Audi, BMW, Citroen, Ford, Honda, Hyundai, Jaguar, Mazda, Nissan, Peugeot, SEAT, Skoda, Subaru, Volkswagen, Volvo. Find your make below.

P1440 on Audi, SEAT, Skoda, Volkswagen

On Audi, SEAT, Skoda, Volkswagen vehicles P1440 is documented as: Exhaust gas recirculation valve, N18, open circuit. P1440 is stored when the ECU sees open circuit on EGR system. That describes how the circuit is behaving, not which part has failed — the wiring, the connector and the component itself can all produce it, which is why the checks below start with the cheapest.

Usually one of: Broken wire, most often at a flex point such as a door hinge or engine mount; Corroded or pushed-back terminal in the connector; Blown fuse on the supply side; Component failed with an internally open winding or element.

Check first, cheapest first:

1. Check the relevant fuse first — it is the cheapest thing that produces this code
2. Unplug and inspect both halves of the connector for corrosion and terminal fit
3. Continuity-test the wire end to end while flexing the loom by hand
4. Measure the component itself against its specification
5. Repair the break or replace the component, whichever the measurement points to

Related Audi, SEAT, Skoda, Volkswagen codes:

P1440 on BMW

On BMW vehicles P1440 is documented as: Purge control valve control circuit, high signal. P1440 is stored when the ECU sees signal too high on the circuit named in the code. That describes how the circuit is behaving, not which part has failed — the wiring, the connector and the component itself can all produce it, which is why the checks below start with the cheapest.

Usually one of: Open ground for the sensor, letting the signal float up; Signal line shorted to a supply voltage; Sensor failed open, which the module reads as maximum; Connector fault interrupting the return path.

Check first, cheapest first:

1. Read the live value and compare with what the conditions should produce
2. Check the sensor ground continuity back to the module
3. Unplug the sensor: if the reading changes, the wiring is intact and the sensor is suspect
4. Inspect the connector for corrosion or a spread terminal
5. Replace the sensor once ground and signal wiring are confirmed good

Related BMW codes:

P1440 on Citroen, Jaguar, Peugeot

On Citroen, Jaguar, Peugeot vehicles P1440 is documented as: Purge valve stuck open. P1440 is stored when the ECU sees open circuit on evaporative emissions system. That describes how the circuit is behaving, not which part has failed — the wiring, the connector and the component itself can all produce it, which is why the checks below start with the cheapest.

Usually one of: Broken wire, most often at a flex point such as a door hinge or engine mount; Corroded or pushed-back terminal in the connector; Blown fuse on the supply side; Component failed with an internally open winding or element.

Check first, cheapest first:

1. Check the relevant fuse first — it is the cheapest thing that produces this code
2. Unplug and inspect both halves of the connector for corrosion and terminal fit
3. Continuity-test the wire end to end while flexing the loom by hand
4. Measure the component itself against its specification
5. Repair the break or replace the component, whichever the measurement points to

Related Citroen, Jaguar, Peugeot codes:

P1440 on Ford, Mazda

On Ford, Mazda vehicles P1440 is documented as: Evaporative emission system leak detected (small leak). P1440 points at evaporative emissions system. The standard definition names the system involved; which part inside it has actually failed is what the checks below establish, cheapest first.

Usually one of: Fuel cap not sealing or the wrong cap fitted; Cracked or perished breather hose; Purge valve stuck open; Charcoal canister split; Leaking tank seal around the pump flange.

Check first, cheapest first:

1. Refit the fuel cap firmly, clear the code and drive for a few days — a surprising share of these are the cap
2. Inspect the visible EVAP hoses for cracks and loose clamps
3. Command the purge valve with a scanner and listen for it clicking
4. Smoke-test the system if the simple checks find nothing — a small leak is very hard to see

Related Ford, Mazda codes:

P1440 on Honda

On Honda vehicles P1440 is documented as: IMA system problem.

Related Honda codes:

P1440 on Hyundai

On Hyundai vehicles P1440 is documented as: Evaporative emission system vent circuit. P1440 points at evaporative emissions system. The standard definition names the system involved; which part inside it has actually failed is what the checks below establish, cheapest first.

Usually one of: Fuel cap not sealing or the wrong cap fitted; Cracked or perished breather hose; Purge valve stuck open; Charcoal canister split; Leaking tank seal around the pump flange.

Check first, cheapest first:

1. Refit the fuel cap firmly, clear the code and drive for a few days — a surprising share of these are the cap
2. Inspect the visible EVAP hoses for cracks and loose clamps
3. Command the purge valve with a scanner and listen for it clicking
4. Smoke-test the system if the simple checks find nothing — a small leak is very hard to see

Related Hyundai codes:

P1440 on Nissan

On Nissan vehicles P1440 is documented as: Evaporative purge control system, small leak. P1440 points at evaporative emissions system. The standard definition names the system involved; which part inside it has actually failed is what the checks below establish, cheapest first.

Usually one of: Fuel cap not sealing or the wrong cap fitted; Cracked or perished breather hose; Purge valve stuck open; Charcoal canister split; Leaking tank seal around the pump flange.

Check first, cheapest first:

1. Refit the fuel cap firmly, clear the code and drive for a few days — a surprising share of these are the cap
2. Inspect the visible EVAP hoses for cracks and loose clamps
3. Command the purge valve with a scanner and listen for it clicking
4. Smoke-test the system if the simple checks find nothing — a small leak is very hard to see

Related Nissan codes:

P1440 on Subaru

On Subaru vehicles P1440 is documented as: Fuel tank pressure control system, low input. P1440 is stored when the ECU sees signal too low on evaporative emissions system. That describes how the circuit is behaving, not which part has failed — the wiring, the connector and the component itself can all produce it, which is why the checks below start with the cheapest.

Usually one of: High resistance in the supply or ground path, dragging the signal down; Corroded connector adding resistance the module reads as a low reading; Sensor drifted out of tolerance with age; Partial short to ground somewhere in the signal line.

Check first, cheapest first:

1. Read the live value on a scanner and compare with a known-good reading
2. Clean and re-seat the connector, then re-test before replacing anything
3. Check the ground point for that circuit — a poor ground causes this far more often than a bad sensor
4. Measure the sensor against specification with the connector back-probed
5. Replace the sensor only once the wiring and ground have been ruled out

Related Subaru codes:

P1440 on Volvo

On Volvo vehicles P1440 is documented as: Fuel cap missing.

Related Volvo codes:

Which one is yours

A generic OBD reader gives you the number, not which of these meanings your manufacturer assigned to it. To get to the specific one:

1. Use a brand-specific scanner — VCDS for VAG, INPA or ISTA for BMW, XENTRY for Mercedes, Forscan for Ford. It shows the manufacturer's own text rather than the generic one.
2. Read all stored codes together — the neighbouring ones usually point at which system is involved and narrow the list.
3. Check freeze-frame data: the RPM, temperature and load at the moment it triggered indicate which system was active.
4. If you have no brand scanner, tell me the make and model below and I will tell you which of these applies to your car.

Code family

P1xxx is manufacturer-specific code (VW/Audi, BMW, Mercedes, Toyota etc. have different meanings for the same code number).

Severity

Manufacturer-specific codes need a brand scanner (VCDS for VAG, INPA for BMW, STAR for Mercedes).

That is what holds for P1440 in general. From here it depends on your engine — tell me which car it is and what it does, and I will give you the steps for it: real procedures, torque figures and diagrams instead of general advice.