ignition problem

**a-teamlambretta** · 20-07-2009,10:30 PM

hi to all this is my first post.

my mother has a 1996 a4 tdi. put key in ignition to start, try to start and the warning light with the key symbol comes up and stays on until key is removed. the car wont start until you have tried it for up to 20 times

. until the warning light goes. i am getting a bit worried if it she stalls it on a junction or worse . its going in for a service on friday at a local garage i have told them about the problem but i could do with a bit of info if this is a common fault and if there is a quick fix or the parts required to fix. thanks simon

**Crasher** · 20-07-2009,10:37 PM

Start off with a fault code read on the engine ECU and the immobilser.

**shark_90** · 20-07-2009,10:37 PM

Welcome to VWAF

It is a common fault. The yellow key symbol is the immobiliser warning light, and it is telling you that the immobiliser is active which is why the car won't start.

It could either be the reader coil on the ignition barrel which reads the key to decide whether it will allow the car to start or not, or more likely the wiring to the reader coil.

Ask the garage to check the wiring and take it from there. I think there is a replacement wiring loom that you can buy for the reader coil but I don't know the part number off the top of my head.

**a-teamlambretta** · 20-07-2009,10:46 PM

wow, thanks for the rapid responces looks like the problem is nearly sorted. any recomendations on where to get the parts if i need them ? thanks again simon.

**Crasher** · 21-07-2009,12:38 PM

You need a fault code read carrying out before you can go any further.

**a-teamlambretta** · 21-07-2009,10:31 PM

i called at a main dealer today to price the parts if needed ....

£231 + vat for the loom.
£80 + vat for the reader coil.

ouch

.
i also called at a local scrap yard. they have an a4 of a similar vintage, could i use the loom off that. could i also use the coil reader or would this need to be matched with the key and ecu ?. also if plugged into a code reader would it tell me if its the coil reader or the loom. . oh one last thing if its the loom what am i looking for i.e. kinks, chaffing, corosion. cheers simon

**Crasher** · 21-07-2009,11:20 PM

LOOM! Why? For ***** sake get a fault code read done, stop guessing!

**a-teamlambretta** · 22-07-2009,12:10 AM

Originally Posted by Crasher

LOOM! Why? For ***** sake get a fault code read done, stop guessing!

as stated in my first post this is not my car so i am trying to help out.
as i dont have a code reader in my tool box i will have to wait until friday. i only mentioned the loom as you might be able to see the fault. i also asked if the code reader would say if it was the coil or the loom or may be some thing else or will it say there is a fault with the imobiliser and then you have to eliminate parts until you find the duff part. all i am trying to do is get as much info for when they give me the good news . cheers simon. so crasher can i use the parts off the scrap audi if needed. if i took it to a main dealer i think it would be a £300 to £400 repair bill it would be less than half that if i could use second hand parts at my local garage. cheers again simon.

**shark_90** · 22-07-2009,12:53 AM

I didn't expect the loom to be that much. The fault code scan is probably going to bring up a Signal Too Low code for the key, it won't tell you if it's the reader coil or the loom so you won't be that much better off really.

If you change the reader coil (can be a pig of a job on some cars as they are attached to the ignition barrel in a rather convincing way) or loom then you do not have to get the keys matched to the immobiliser or ECU so you're safe there.

**a-teamlambretta** · 22-07-2009,08:32 AM

i thought that the code reader would not pinpoint the fault. and its good news that i might be able to use the second hand parts. thanks again i will keep you posted as and when progress is made. thanks simon