P24B9: Evaporative Emission System Leak Detection Pump Pressure Sensor Circuit Range/Performance
What to do
This is a low-urgency fault and the car will drive normally. It concerns the system that checks the fuel tank for vapour leaks, not anything that affects how the engine runs.
It matters at MOT time. While it is stored the vehicle cannot complete its evaporative emissions self-check, and an incomplete readiness monitor can fail the test on its own — so leave time before the MOT rather than booking it for the same week.
Mention if you can smell fuel at any point. That would suggest a genuine leak alongside the sensor fault, and it changes the priority considerably.
Keep the fuel filler cap tight and correctly seated. It is part of the sealed system this pump tests, and a loose or perished cap seal causes related faults.
What this code means
The pressure sensor inside the evaporative emission leak detection pump is reporting an implausible value.
This belongs to the fuel vapour system rather than the exhaust, despite sitting in a block of aftertreatment codes. Its job is to prove the fuel tank and its vapour lines do not leak — which the vehicle tests by pumping the system up or drawing it down and watching whether the pressure holds.
The sensor in question is the instrument for that test. So this code does not say the tank leaks; it says the equipment that checks for leaks cannot be trusted. No leak test can run while it is stored, which is why it blocks an emissions readiness monitor.
Range/performance means the reading is present but wrong. The classic evidence is a sensor not reading atmospheric pressure when the system is open to atmosphere and the engine has been off for hours — at that moment every pressure sensor in the vehicle should agree, and one that does not has declared itself.
The pump assembly is usually replaced complete, because the sensor is generally built into it rather than serviced separately.
Check the obvious first. The unit is mounted near the fuel tank or charcoal canister where road spray reaches it, and a blocked filter or a hose full of water produces this code with a working sensor.
Likely causes
Start here
- Faulty EVAP leak detection pump · moderate
- Corroded or loose connector · easy
Less common
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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