Flipping Immobiliser again!

[scos]

The damn 16V won't start again. Just left it overnight at my work and now it won't start. Turns over ok but won't fire. I'm 90% sure its the immobiliser again as I had the same problem a few months ago. The problem is I never really resolved it last time, it just started working again randomly.

I tried taking all the relays out and having a look at them and checked all the fuses, last time it just worked after I did that but this time still no joy.
Incidentally does anyone have a plan of what the relays do? I've lost my Haynes manual and it's not marked on the fuse guide.

I'm trying to get an Auto Electrician to look at it but have been told that its a dealer only job cos of the ECU coding - please tell me there's another way cos I can't afford a visit to the stealers

Please help

 

[kiearn]

The immobiliser will stop it from even turning over. You will just get nothing when putting the key in and turning. Is there enough juice in the batt ? Try jumping it and then get the voltage checked.

 

[scos]

Interesting. When I had a similar problem a few months ago the engine turned over but wouldn't start. VAGcom showed the fault code that the engine start was blocked by the immobiliser.

I've managed to get the VAGcom on it again today but there is no fault code on the engine or immobiliser so I'm now thinking it might be more basic. I will return to it tomorrow with some tools and check the basics, i.e. fuel, spark.

 

[Wallis22]

I had/ have the same problem with my Toledo TDI90. The engine cut out in traffic and the car had to be towed off the motorway. The car would turn over but wouldn't start.

The AA ran a fused live feed from the battery to the fuel cut off valve and he said something about the immobiliser. The only problem with that was i had to remove the fuse whenever i wanted to turn the engine off, and the car lacked power.

I took it to a garage and they ran a fused live feed from the ignition so i didn't have to keep removing the fuse. (for a charge - £20). This garage couldn't fix the problem so i took it to a VW specailist (apparantly!!) They told me it was the fuel cut off valve. I replaced this but it still didn't work.

In the end i had to bite the bullet and take it to SEAT. They traced the fault back to the ECU and said i'd need a new one, at a cost of £800!! The car's only worth about a grand so i asked them if they could do anything else, so they re-wired the ECU. (whatever that means.)

Anyway, the morale of this story is; for serious engine electrical problems, SEAT are your best bet as they built the car so they know how to fix it. The VW (apparant) specailists were worse than useless. They charged me £40 for absolutly nothing. They even tried telling me the clutch needed replacing! (It didn't) They tried telling me that 1st gear spools up the turbo for the other gears, and that the clutch was slipping in 1st and that was why the engine lacked power. Erm no.., more like the ECU had been tricked into running, hence the lack of power!

They hooked it up to Vag com and got a fuel cut off valve fault code. From that they assumed it was the cut off valve it's self that was at fault. But as someone on here pointed out, if you give the valve power, (from a fused live feed) it works so it couldn't be the valve it's self. (Which it wasn't, it was the ECU.) Some specailist, huh?

Anyway, as much as you don't want to, i think it's a job for SEAT. They'll hook it up to Vag com for £40 and then you can go from there. Some garages will say they can hook it up for £20. But when you get there they might have to do "deep diognosis" and charge £40 (which is what happened to me.) I wasted £60 trying to save money. I wish i just took it to SEAT in the first place...

(Sorry for the long post.)

 

[ryderf3]

I had exactly the same problem last week it turned out to be the coil pack, £39 + Vat from german, swedish, Also the VAG picked up the same code on mine if the code number was P1570, Then I cleared it and didnt come back but still wouldnt start so I think that might have been an old fault. Mine had fuel but no spark. Hope this is the same as yours because its a cheap fix.

 

[scos]

Got the full version of VAGcom on it today and no fault codes at all. Checked the spark and looked okay. I've turned it over god knows how many times now and I can't smell any fuel anywhere so I'm now thinking it's fuel-related.

It can't be the fuel cut off valve as I have no fault codes logged. It sounds like the fuel pump is priming when the ignition is switched on but I'm not 100% sure as there's a bit of background noise where the car is at the moment. I tested the fuel pump relay using VAGcom and it appeared to operate although I guess the contacts could be corroded? Still haven't been able to find a diagram of the relays.... Can anyone scan the relevant page in from their Haynes manual??

Going to try a tow start later today, otherwise I will have to come back tomorrow with my tools and check a load more things. Thanks for your help so far guys.

 

[Cupra Kid]

Had this happen with a few of my cars, Coil, Spark plugs and distributor were the main culprits. With an immobiliser fault on a MK2 the engine should run for a few seconds before cutting. It may sound daft but you've not had the keys open recently to change a battery or something and lost the chip have you? Might be worth trying the spare key.

 

[scos]

People have suggested the spare key before but my spare doesn't have any buttons on it - it just looks like a normal key. Does it still have a chip in it? At the moment it's on the same key ring so should be picked up by the sensor anyway I guess? (is that how it works??)

I haven't changed the battery in the key fob recently but it could be low I guess. I've got a spare somewhere so I could try that on Monday (the car's stuck at work at the mo). Did try resynch'ing it the other day too but no joy.

Yeah I was thinking it could be ignition related but there is a spark - mind you I only verified that by pulling out one of the leads and testing using a spare plug so doesn't necessarily mean there is a spark on the plug in the chamber. But even if not all the plugs were sparking there would be some kind of ignition wouldn't there?? Or would be a bit of a coincidence if they all stopped working at the same time

Well I've joined the RAC now anyway. I'll call them out on Monday and see what they think. Haven't really got the time to haul all my tools up there (my work is a bit of drive away) and test a load of stuff properly.

Will keep you posted as I know its useful for people to search back later - that's what I've done in the past.

 

[Wallis22]

Hope you get it sorted mate. Let us know how you get on.

 

[scos]

Right - RAC man sorted it today

He pointed out that as I was turning it over you could see a spark inside one of the leads on the dizzy. I feel like an idiot now - I could've easily checked that and, in fact, I almost bought a new set of leads the other day....

He just sprayed a load of WD40 over the dizzy and leads and eventually got it started after fiddling with them all for a while. He advised me to get a new set of leads, dizzy cap and rotor arm. Ordered them today and picking them up tomorrow so hopefully will cure the problem.

Thanks guys