I have problems with a Focus Diesel that won't start and the fuel
gauge shows that the tank is empty. But we filled it up recently and
have not driven since then. The start engine runs as it should and I
have tried to check the gauge connection at the tank. I have also
disconnected the battery to try to reset the electronics.
Does anyone have some suggestions?
The haynes book says that the ecu will not let the engine run if it
thinks the tank is empty. It also induces a misfire when the level is
low, to let you know fueling is required. This it to stop air being
sucked into the fuel system. It also says that the fuel gauge is
controlled by the ecu. Do the other gauges work ok ? I suspect faulty
fuel sensor/ connectors ( or an empty tank.. ) Disconnecting the
battery is not always a good idea, the ecu will have to re-learn all
it's settings and any stored fault codes might be lost.
On the Diesels, when the fuel level drops to 35 units (with the dash in DTC
mode you can see the fuel remaining units) the ECU shuts down the engine.
So, if your fuel sender is faulty, and 95% of them go faulty on Foci, the
engine shuts down.
Replace the fuel sender and lift pump. (about 100 quid + labour)
The problem is that the variable resistor wiper looses contact with the
track. Whilst the tank is less than brim full the wiper moves about enough
to eventually give the ECU a value. This is not noticeable to the driver.
If the tank is filled past the "first click" stage, the wiper is held in one
place on the track. The ECU doesn't see a value, so puts the low fuel light
on and sends the gauge to zero. With a petrol vehicle, just using it to
lower the fuel level to the point where the float is flapping about again
usually restores normal operation. Bit more of a problem with a diesel...
With regard to the rate of failure, I'm willing to bet that 99% of Foci will
show "Fuel sender faulty" in the DTC codes!
that's good to know, my focus is under warranty for a year yet, is
there any way to provoke this 'faulty fuel sender of death' situation
? Why didn't they make it reliable if it's a single point of failure I
Well, you could keep brimming it when you refill. Of course, this may cause
a fail to start if a diesel :-)
You may not know how to check for DTC codes - have a look here:
A code of 9202 shows that at some time the fuel sender has failed open
circuit. However, when you speak to a dealer they will only say "They all
do that Sir".
In 7 years mine has only done it once. As the tank level fell, normal gauge
operation returned. I always stop filling on the first click now.
There's a difference from filled to the top and filled to the brim.
I could provoke a dead gauge at any time on my 2000 1.8 Zetec by pulling the
nozzle almost out and filling until fuel was visably in the filler neck. As
Chris says, using up some fuel so the sender's wiper came back onto its
track restored gauage operation.
Luckily the petrol models ECU doesnt cut the engine when it senses a 9202.
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