Mk5 Immobiliser / fuel injection issues

[Jbizzle]

Hi All,

I'm new here, so apologies in advance if I sound like I don't know what I'm talking about (it's because i generally don't!)

I bought a Mk5 (X-reg) 2.5l swb transit as a camper last year and I had to get towed home the other night when the van's immobiliser started kicking off and wouldn't let the key turn over. I've had problems with the key barrel before and assumed it was this, but had the key man out today who told me it was something to do with the EPU / PATS box being on the blink so the red light would flash and stop me starting it. The van's fitted with at cobra aftermarket alarm , but this isn't part of the problem, I didn't realise the van had an immobiliser from the factory.

The key barrel will need replacing at some point anwyay, but for now, he said I can get myself a second hand key and reader and PATS box...and I can't quite work out what it all is, and am obviously keen to get the right parts before I get somebody else out to do the work.

Looking online I'm a bit clueless, so was hoping for some help.

I know it also sounds like I stole the van, so can uplaod photos etc to prove it is mine cheers in advance.

[Jim Archer]

After a few minutes of flashing rapidly, the PATS LED will settle into a 2 number code output i.e. number of blinks - pause - number of blinks - long pause - etc.

Let us know the code, it will tell what's up with it.

Key barrel is easy to swap, then just transfer the transponder chip to the new key.

Jim

[Jbizzle]

Hi Jim,

Trying it today, every now and then the main key turns over and the engine starts no worries, then every now and again it won't budge to any position.

One of the door keys also turns in the ignition, which I can get to position 2 (lights on the dash etc) even when the main key won't turn (so I know it's not the key barrel). When I get the door key to turn to position 2, the immobiliser flashes fast rpeeatedly. When I remove the key it goes back to flashing evenly and regularly. No pattern I can make out.

Seems to be luck of the draw whether it will start or not.

I should also mention at this point there is a high security clamp over the key barrel / steering column, so although I have a replacement barrel and blank keys, I can't change it without getting the clamp taken off.

Cheers, and thanks for your reply

Josh

[twin wheel camper]

The door key isn’t a chip key I assume?
Try when using the door key holding the worn key as close as possible to the ignition key and it will start. The immobiliser needs read the coded key to allow it to start.

[V184]

Normally if it wont turn over & is immobiliser related its the dds module on the back of the injection pump playing up

[Jbizzle]

Have tried holding the chip key next to the reader while using non-chip key in the lock, and nothing. Sounds like the immobiliser playing up?

As I say, sometimes it turns over, sometimes it doesn't.

How necessary is it to tinker with the back fo the fuel pump, because I know the immobiliser system has something to do with this. Sounds like it could be a fairly big job? Not sure where to turn really...

Josh

[vanfox]

If you post your whereabouts maybe one of us with time on our hands may live in the next street....

[MinorMatt]

Absolutely! I was about to ask the same

[Jbizzle]

Farnham in Surrey...

[MinorMatt]

How competant are you with the spanners?

I could get to you on sunday and probably diagnose the fault, but immob can be bypassed with a little spanner work.

I have a module that goes on the pump (most common problem) which I could program in - but not the under dash one - to hand. Would need 240V supply though

[Jbizzle]

Medium competant, but have friends who could help out...
What's the chances of me causing serious damage?!

[MinorMatt]

Not much...

But if the worst come to the worst you can just bypass it

[Jbizzle]

I'm up for bypassing it...! I'm all ears.

[Don-44]

Hi,
I've got the same fault, had the dash off to "fix" it to trace the wiring . Nothing at all to begin with and then put an earth on the Yellow starter relay on the passenger side and van turned over but wouldn't start. Then all of a sudden it started and kept starting until I got the dash all the way back in! So now not confident to take it out if it does start intermittently.
Anyone able to let me in on the 12v short you can put on the Fuel pump/DDS please I've wasted so many hours trying to trace this fault!!....Many thanks.

[vanfox]

See post above.....2