P0443
PowertrainEvaporative Emission Control System Purge Control Valve Circuit
The EVAP purge valve circuit has a fault. The ECU isn't getting the response it expects from the purge valve electrically, which suggests a wiring issue, a failed solenoid, or a connector problem. The purge valve is what allows fuel vapour from the charcoal canister to be drawn into the engine and burned.
ⓘ Information only. This page provides general educational information about fault code P0443. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.
Recommended next steps
Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.
What does P0443 mean?
P0443 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Evaporative Emission Control System Purge Control Valve Circuit.
This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms commonly associated with this code
Symptoms that drivers often report alongside this code. Not all may apply to every case:
- • Engine warning light
- • Sometimes a faint smell of petrol
- • Drivability typically unaffected
- • Possibly hard starting after refuelling on cars where the valve is stuck
- • Occasionally rough idle if the valve is stuck wide open
Possible causes
Causes commonly associated with P0443, listed in approximate order of typical investigation. The actual cause on a specific vehicle can only be confirmed by professional diagnosis.
- 1. Failed purge valve solenoid (open or shorted internally), the most common cause
- 2. Wiring damaged between valve and ECU, often where the loom passes near the engine
- 3. Connector at the purge valve unplugged, contaminated, or with backed-out pins
- 4. Blown fuse in the purge valve circuit (where it has its own fuse)
- 5. Less commonly: ECU output stage fault on the valve circuit
- 6. On rare occasions: damage to the valve from contaminants in the EVAP system
How mechanics typically diagnose
A typical diagnostic sequence used by mechanics, provided here for educational reference only. Diagnostic work should be performed by a qualified mechanic with the appropriate tools and training.
- 1. Locate the purge valve, usually on the intake manifold or close to it
- 2. Inspect the connector physically, check for damage, oil contamination, backed-out pins
- 3. Test the solenoid resistance against spec, typical is 20-40 ohms; an open or short reads outside this
- 4. Verify 12V supply to the valve with ignition on
- 5. Apply 12V directly to the solenoid terminals, it should click and switch flow paths
- 6. If solenoid is healthy, check wiring continuity back to the ECU
Common questions about P0443
Will it fail my MOT? +
EVAP codes don't directly affect MOT emissions readings, but if the engine warning light is on at the time of test, that's an automatic fail under MOT rules for cars from 2018 onwards. Fix the underlying fault first, drive a few cycles to clear the light, then book the test.
Difference between P0441 and P0443? +
Both are purge valve faults but different angles. P0441 is the flow-incorrect code (the valve is flowing but not the right amount). P0443 is the circuit malfunction code (electrical fault in the valve circuit). They sometimes appear together; the diagnostic approach is similar.
Can I just unplug the purge valve and ignore it? +
No. Disconnecting the valve sets a different code (P0443 specifically), and the ECU may also throw additional EVAP system codes. Modern cars can also fail emissions if the EVAP system isn't working. Fix it properly rather than working around the issue.
Information only, not professional advice
The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →