T4 Reset of immobilizer

Huckfead

2005-12-27 15:32:01 UTC

Post by Huckfead
Having a monster problem getting my T4 Van to run.
Seems the immobilizer has activated against it's owner.
Nice.
Why?
Dunno.
I removed a phone car kit (going Bluetooth instead of being locked in
to a articular Phone type)
That involved simply disconnecting the power, (and would you believe a
3.6 volt line), earth and a few other physical things.
This model is an Australian 2000 VW T4 Van with the immobilizer
separate to the instruments - it's actually mounted to the left of the
gauge cluster.
And yes, I've been in there and there's noting melted, burned of
otherwise 'looking' defective. It has a 99 model chip in there.
All wiring to and from it is intact, and there are no fuses blown
either.
Found a reset procedure for the thing that should work, on the web and
relevant to (I think) USA models of the vehicle which is supposed to
give one start and then activate the immobilizer after a few minutes,
but that procedure simply won't work on this car.
There is an aftermarket radio in there, which may be a problem, but I
don't see how that could be, since it's been in there a few months now
to no ill effect - it plays MP3's just fine.
I also installed a door storage pocket on one side.
That's about it - all the tampering I could manage:-)
Anyone got any ideas on next moves for me other than burning the blddy
van to the ground and buying ann older van with no manufacturers
interference in ownership if the thing.
(I'm about 50Kms from the nearest VW dealer which is a problem of time
and expense of pretty hefty proportions, mainly because we're having a
holiday here and the local tow trucks are busy as hell with prangs in
addition to tyying to have their own holiday.)
Ideally I'd like to totally remove the damm immobilizer and replace it
with an aftermarket one that allows the engine to keep running but
stops the car if the speed sensor gets a move.
But I get the feeling that doing that would involve fixing the
immobilizer system, and leaving it there with the RFID chip glued to
the detector coil case, rather than rebuilding the electricals from
the ground up:-)

OK, I'll answer my own post:-)
Problem tis fixed.
What was it?
I worked on the assumption that the problem just couldn't be the
immobilizer.
So, car kit was connected to a wire that had 3.6 Volts. Stangely that
wire goes to almost 17 V on cranking.
Fluke multimeter, too.
Anyhow, the car kit circuit went from there via the kit and earthed.
I really don't recall if it was actually connected to the fuse block.
Maybe it was.
Anyhow, I found the appropriate place for the plug the thing has, and
bingo - the van behaved as normally as it ever did.

There's a bonus though.
I decided to tidy up the wiring, and did so, and very carefully fitted
the (broken by some ham-fisted oaf contracted by previous owner)
auxiliary fuse block, as well as the cover under the whole thing.
And no start.
No fuel pump.
Starter spun up and turned the motor over though.

Good grief.
So I disassembled the thing again.
And a plug loose - the main feed for the fuel pump.
Get this - one thin wire had managed to jam in the right place to
flick the lock tab of the plug, and the act of rotating the fuse block
put up just enough pressure to both pry the lock tab to unlocked
position and break the contact in the plug socket assy.

This van has the proverbial mind of it's own. Then odds of that tab
being keyed by the wire are quite high..

Anyway, all is well with the T4 now.
Off to work I go....