P008A: Low Pressure Fuel System Pressure - Too Low
What to do
Ask when the fuel filter was last changed. A restricted filter is the commonest cause of this and by far the cheapest to put right — worth eliminating before anything larger is considered.
Do not put off the repair. On a direct injection engine the fuel lubricates the high-pressure pump, and running it short of feed pressure wears that pump out — so a fault that starts as a filter can end as a pump plus a system flush.
Ask for the voltage at the fuel pump to be measured under load, not just its resistance. A corroded connector slows a perfectly good pump, and that is a much smaller repair than dropping the fuel tank.
Try to keep more than a quarter of a tank. Fuel around the pump helps cool it, and a struggling pump run near empty fails sooner.
What this code means
The low-pressure side of the fuel system is below the pressure it should hold.
A direct injection engine has two fuel systems, and separating them is the whole point of this code. The low-pressure side runs from the tank pump to the high-pressure pump at a few bar. The high-pressure side runs from there to the injectors at a hundred bar or more. This code names the first of those.
Which matters because low feed pressure damages the high-pressure pump. These pumps are lubricated by the fuel passing through them, and a starved pump cavitates rather than compresses — so it wears rapidly and its debris then circulates through the whole system. A cheap fault left alone becomes an expensive one.
The causes are ordinary and ordered by cost.
- A restricted fuel filter, which is the commonest and cheapest. Worth eliminating first on any vehicle with an unknown filter history.
- A weak or worn tank pump, or a blocked strainer on its inlet.
- A leak or air ingress on the suction side, which is compressible and defeats a pump entirely.
- A wiring fault starving the pump of voltage, which reads as a weak pump and is not.
Measure the voltage at the pump under load before condemning it. A corroded connector drops enough voltage to slow a healthy pump, and that is a far cheaper repair than dropping a tank.
Expect hard starting, hesitation under load, and cutting out as the fault worsens.
Likely causes
Start here
- Restricted fuel filter · easy
- Weak fuel pump · moderate
Less common
- Blocked fuel pump strainer · moderate
- Air drawn into the fuel supply · moderate
- Low voltage at the fuel pump · moderate
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
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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