I've tried differing posts to solve a non starting vehical and my efforts have lead to this try. I need to know 'something' alike to resetting the ecu or rewriting its internal program, it may also apply to the immo(not possible?).
    The reason being to scratch another faultless item of my van off of its immobile list.*
This centers around the vans inability to start FROM a faulty/flattish battery casting a spell on the electrics somehow. Somehow being the point...whatever ticks IN the ecu or immo - this was picked up by vagcom as a intermittent fault com error and needed to remeet/match the two together again. Which to the untrained eye but not my surprise happened, but then it hasn't started from around that time, probably not coincidental, which lead me to fix all distributor components.$$

So you might see this problem or you see a noob. Reset was suggested to be disconnect battery, another to tap + 10 times to activate a reset? Is there a real way to tell the ecu (if there's time the immo as both seem tied in to thinking for the van) to reset? How do I do this please?

Van is: vw 2.0 1997 7da t4 petrol man. 2nd gen immo or ecu? Every thing checked so far is in working order so it may be plain to see.

         *A post put it kindly as y2k but really a reboot/read programing problem _ looped!?!


A nice point would be to know how to recognize  broken it may be, or is that a testers job.

HELLO, HELLO IS THERE ANYBODY OUT THERE¡!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 ??

Nil

The immo needed connecting to the ecu but once done there is no error codes to mention of, the only ones got cleared eg airbag, sensor. Nothing since.

Nada.

Can a faulty ecu (engine management) be this quiet?.

I've checked a lot of items on a list of possibilities and everything checks a green box, other things need a professional. No spark is the latest-after changing hall sensor, rotor, cap_ checked current of coil and ignition switch, cleaned idle regulator, throttle, adjusted throttle switch, recharged batt, fuel pump+filter, thermal sensor tests, vacume tube replacements, vagcom lite registered test............this is ongoing until SOMETHING is wrong.

It only leaves immo and ecu .... How do I check them?

WELL ITS GOT ME BEAT, ALL PARTS LEADING TO IMMO,ECU WILL BE REPLACED UNTIL THEY GET REPLACED. WHY VAGCOM CANT SEE THIS IS dum!

All good, emptied tank to check connection with pump.
Anything I've touched so far works.

The system can't get a virus can it?

No.


No spark ,no firing.
New hall sender rotor cap, tested/cleaned sparky ,leads ,ignition coil, ignition lock and switch (2nd hand, getting new any day now)...rotor turns, cranks good, recharged battery. No spark though....

No virus is good news, means I can rely on the info inside both units.
The immo wouldn't JUST shut the door and stop the starting of the vehical would it?. It sounds like it won't feed anything when ignition turns to start...

No nothings added to stock system, and further tests this week found elec. IS getting past the ignition transformer (coil), although this significance lost with no knowledge of how to use the multimeter on sophisticated electrics_ but I can learn.
The numbers were like this 15.5 ignition on, 10.0 cranking. As long as there was a current.

1. Immo _ Do you mean a 'last gasp' before never working again. That happened. Happening. I'd just stalled at startup which included a noisey raspy sound of the immo resetting. Stopped starting like it is now, then somehow I got it going again went for a spin and to this day won't start again. At this time I re-met the immo to the ecu like vgs said, but that was kind of clicky anyway.
    Is that KILLING my van?? or its more kind, only allows to start and then splutters to a stop. Similar to a unknown key)

I've read a blog about removing the immo, what is the safe procedure electrically/programmably.

Conclusion, apart from the initial symptoms being the same (flattish battery, rough idle etc, stopped) options left seem to point only at immo,ecu and battery current_by that I mean is voltage changed before starting? The others a involved somehow.

If that sounds plausible.

OH thank GOD !!

Because its really dead.

Removing the immo....(means the entire dashboard!!)

It can stay dead.

Bye.

   BITTER SWEET.

Great news its easy, leaves an option when at the last stop.

Its got me stumped, today I replace the spark plugs and will with each component ,working back through all options until up to speed.

Also noticed ENGINE WARNING LIGHT FLASHING when ignition/cranking. Any ideas where that fault lies?.

You sure its getting power from the fusebox? Relay issues are pretty common on T4s.