Being old school or just plain old I am not up to speed with modern electrics. My wife's C4 shows a "antipollution fault " and the engine management light is on intermittently . Apparently this is a very common fault on Citroen and after trying different things I gave up and sent it to the local garage. They replaced the coil and plugs, £260.00, but within two days it was back on.

Then yesterday it would not start at all, I called the AA and they said that their diagnostic shows Crankshaft position error, injection valve cylinder four, starter triggering malfunction, brake switch malfunction, coolant temp sensor outside range, radiator fan faulty, ignition coil faulty among many others. I had it towed back to he garage and they said they have checked out the faults shown and all appear to be functioning, they therefore suggest that its a vehicle control body module fault, unfortunately Citroen no longer supply these items so they will try to source a used one and reprogram it.

The question is that its a 2005 C4 Coupe', in nice condition, but only worth probably £1,200 so how far do I go, they say it could cost £400 to £600 to repair do I just cut my losses and scrap it or has anyone got any other views.

Daughter had a C4 with similar, it was the vvt valve which was stuck 'open'

When she tried to start it is gave the impression of no compression, a light tap on the valve kept it running long enough tontrade in.

If you have a way of reading live data (via OBD) check what the battery voltage is at the time the faults ping. They may be logged as 'pending' until they meet the criteria to ping the EML. I've seen a few folks spend a lot of cash chasing sensor faults only to finally try a new battery and the faults go away! It may be worth a look?

Have a look on C4owners.org - there is a lot of useful info on there which may help