I have a 54 plate fabia Vrs that starts and runs perfectly but is flashing up a fault code 18009,i have done the usual searches on here and the net to know avail,a couple of people have said its related to the battery,i have fitted a new Varta battery and cleaned up all the earth contacts that i can find but every time i clear the code it comes back as soon as the car is started.just clicked over the 100,000 mile hurdle with very few faults...any help or ideas would be very welcome.

Is it causing you any bother?

If not I wouldn't worry

18009 - Relay for Supply Voltage Terminal 30 (J317): Implausible Signal

P1601 - 35-00 - -

Likely to be either a noisy relay, or corroded bus bar fuses on top of the battery. I think the relay in question has 458 stamped on top.

Thanks,i will have a look asap and let you know if it cures the problem.