01 Jetta starts & immediately stalls. - intermittent problem

doing a immo delete will cause the light to quit flashing and the car to start. That is actually a good idea, sorry I didn't think of it earlier.

problem is that it's a bit pricey. Usually a downside would be that the car would not run while the ECU was out, but that's not a problem in this case

You will still have problems with a remote start I think due to glowplugs...but I don't really know much about remote starts (maybe they have systems that deal with glowplugs)

logically, it seems like the light would still flash. The immo delete is done in the ECU, right? that means the immobilizer (in the cluster) is still there, but the ECU just ignores it, right? therefore, i would think the immobilizer would work just like it currently does, but the ECU doesn't care, and runs the car anyway. Maybe if the ECU isn't asking for immobilizer verification, then the immobilizer stays dormant?

A new cluster isn't cheap either. $525 from the local dealer. If the problem is the antenna ring, it's $177 for a new lock cylinder re-keyed to work with my existing keys. how much is the immo delete?

I have a spare car.......but, i have to drag it out of storage and charge the battery.

as to the remote start, there are diesel models. I'm kind of surprised that nobody has popped up, and told me not to bother, the cars don't warm up from idling......that's usually what happens on this board as soon as somebody mentions remote start. (yes, i know the car doesnt warm up, but the auto transmission sure does. it's like night & day difference if i idle for 5 minutes on a cold day.)

__. Mike, I'm surprized that the VCDS (nee VAG-Com) reset doesn't work for you. In most of the cases like yours that I know about, the "touch the cables together" trick works; in most others, recoding with VCDS solves the problem permanently. Are you saying that you can recode the immobilizer with VCDS and it starts but then the next time you come back, you have to recode again?

__. If that's so, then I still lean toward the view that you have a problem that's causing your immobilizer to "forget" that it's coded or there's some recurrent "boot up" that's causing the system to start from scratch every time.

__. It appears to me that you have an uncommon problem.

GutWrench - I didn't try to re-code it yet. There is an "immobilizer bypass" function in the immo-3 that allows a car to be started and driven using the SKC and Vag-com. That's what i'm referring to.

What do you mean by "re-code it"? Do you mean for me to try to re-code all y keys, and see if that fixes the problem?

By the way, the oscilloscope experiment was very interesting. There is definitely communication going on, and you can easily observe it using the suggestion i mentioned earlier. it's actually quite a strong signal. while i was diagnosing using the coil of wire, it succesfully passes the immobilizer check about 20% of the time now (vs 0% before). i wonder if the reader coil is somehow amplifying the signal?

Eureka! i *think* i found my problem. someone has F'ed with this system before.

http://i129.photobucket.com/albums/p205/mark129845/PICT0024-1.jpg
http://i129.photobucket.com/albums/p205/mark129845/PICT0023-1.jpg

I pulled the trim off the steering column, and look what i found. the wires leading from the ignition switch antenna ring to the cluster have been cut & spliced previously.

I have no idea why anyone screwed with it. i wonder if someone tried (unsuccessfully) to add a remote start without understanding how the immobilizer works?

I bought the car with 60K on it. it must have been before that. This isn't the only instance of non-factory wiring that i have found. I hate hacks.....

I'm going to try to clean this mess up. I'll report back.

Mike

mike944 said:

(snip) What do you mean by "re-code it"? Do you mean for me to try to re-code all y keys, and see if that fixes the problem? (snip)

Click to expand...

__. Yes, that's exactly what I mean. It's only a guess and my gut feeling is that this won't solve your problem but it *has* solved similar but less complicated problems for others. And it's a 6-minute procedure so it's not much of an investment. I'd give it a try.

__. As I said in a couple of earlier posts, my guess is that it's some random (and probably intermittent [ouch!!]) problem that's causing your immobilizer to forget that it should accept the code. But the re-coding (called "initializing" in VW's documents) is at least worth the try, IMO.

(BTW Interesting observations on the o-scope.)

well, i fixed the wiring hack, but it didn't solve the problem. I recoded the keys, and that seems to have taken care of it.

I was a little nervous about trying to re-code the keys, since there was a zero for all keys in measuring block group 22, field 3, which ross-tech says the following "The value in field 3 must be 1. If value is not 1, the key is not capable of being adapted to Immobilizer" But, since i was pretty much screwed anyway, i figured what the heck, why not?

It seems to have worked. we'll have to wait and see how long it works for.

Thanks everybody!

Mike

P.S. if anybody feels the desire to reverse-engineer the immobilizer to key communication, it happens on a carrier frequency of about 220khz, with the data stream occuring about 10x that rate. A coil of wire around the cylinder of 10 turns gets you a very usable signal of about 1v peak to peak on the carrier frequency, and about 0.1v p-p on the data stream.

mike944 said:

I recoded the keys, and that seems to have taken care of it. (snip)

Click to expand...

__. Hope it stays OK for you.

Well...........it worked fine for 2 weeks, now it's dead again. Same problem. Signal too low.

I just put the ECU in a box to Jeff for an immobilizer delete. The way i look at it, that will be one less electrical item to break again in the future.

the only remaining problem will be with the immo delete, the immo light on the gauge cluster will flash. that's going to bug the crap out of me. maybe i'll open up the cluster and remove the light bulb.

you're having him tune it while he's at it right?

mike944 said:

Well...........it worked fine for 2 weeks, now it's dead again. Same problem. Signal too low.

I just put the ECU in a box to Jeff for an immobilizer delete. The way i look at it, that will be one less electrical item to break again in the future.

the only remaining problem will be with the immo delete, the immo light on the gauge cluster will flash. that's going to bug the crap out of me. maybe i'll open up the cluster and remove the light bulb.

Click to expand...

Did Jeff say that the immo light on the gauge cluster would flash? I did not know that; I figured he could satisfy the links. Please let me know the end result.

I am considering pulling the bulb for my cruise control light. I consider it totally worthless. I plan to do it during my donial Boost/EGTgauge install.

Yes, he said the Immo light will still flash. the update is to the ECU.

As i understand it, the immobilizer checkes the key. if it fails the check, the light will flash, and it will tell the ECU not to run the car.

When you go to start the car, the ECU asks the immobilizer if it's ok to start the car. the immobilizer responds with a yes, or no. The ECU then runs the car or not based on what the immobilizer said.

With the delete option, he only updates the ECU. i think the first part still happens (immo checking the key) the flashing immo light is the immobilizer telling you that the key is no good. The difference is, the ECU never asks the immobilizer if it's ok to start the car, it just starts it anyway. in other words, the ECU no longer cares what the immobilizer thinks. But, the immobilizer is still out there, running along, and checking keys, preparing to respond to the ECU with an answer to a question that the ECU is no longer asking.

At least, that's how i understand it to work.

Sounds probable to me.

Whatever happened to the immobilizer delete and the idiot light ?

I forgot to post an update.

Got the immo delete from Jeff. No problems at all.

Yes, the immo light kept flashing. After a few months of attempting to ignore it, i finally removed the cluster, removed the gauge face, and removed the little LED with a pair of needlenose pliers. The gauge cluster still throws a code, but i don't have to look at the flashing immo light anymore.

I just did a 5-speed conversion. No issue with re-coding the modified ECU to tell it there's no more auto transmission controller.

I'm due for a state of CT emissions test. I'm pretty sure they only scan the engine controller for codes, but i guess i'll find out pretty soon.

DanG144 said:

The Coolant temperature sensor could be a totally separate failure, or it could be related. The CTS fail often enough that I would just replace the sensor, if it were my car.

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In my case I had the same symptom, with a new beetle with immo3.
Engine starts but then stops after 2 Seconds
I also had on one occasion had the very same Coolant temperature sensor error code.
After clearing the codes the immobilizer code was re-created but the coolant sensor one went away and stayed away
My solution involved replacement of the immo reader and keybarrel, plus the pairing of the ECU to the instrument cluster. Root cause not entirely obvious.

Hi All,

I just wanted to go on record that the immobilizer reset "procedure" worked like a charm for my 2000 Golf! This comes after the car sitting for almost 2-years and my just doing the TB change.

After spending hours diagnosing fuel delivery issues I found this post and this morning gave it a try. Here is what I did: 1) Fully charged the battery overnight since I had weakened it trying to get the darn thing to stay running. 2) Found another key, 3) disconnected the battery terminals and jumped them together while I turned on the ignition for 10-15 seconds. 4) After reconnecting the battery it started right up.

KellysHero said:

Hi All,

I just wanted to go on record that the immobilizer reset "procedure" worked like a charm for my 2000 Golf! This comes after the car sitting for almost 2-years and my just doing the TB change.

After spending hours diagnosing fuel delivery issues I found this post and this morning gave it a try. Here is what I did: 1) Fully charged the battery overnight since I had weakened it trying to get the darn thing to stay running. 2) Found another key, 3) disconnected the battery terminals and jumped them together while I turned on the ignition for 10-15 seconds. 4) After reconnecting the battery it started right up.

Click to expand...

Glad to hear it's working.

Mine has been working just fine with the immobilizer delete for the last 3 years.

Thanks!

Just wanted to thank everyone for posting this solution. I had the same issue on my '01 Jetta TDI -- tried the method of connecting positive to negative battery cables reset the 'immobilizer". I was about to have the thing towed to my mechanic to have him start troubleshooting. This post saved me bit of cash, thanks!

Crap. I'm Immobilized.

KellysHero said:

Here is what I did: 1) Fully charged the battery overnight since I had weakened it trying to get the darn thing to stay running. 2) Found another key, 3) disconnected the battery terminals and jumped them together while I turned on the ignition for 10-15 seconds. 4) After reconnecting the battery it started right up.

Click to expand...

I've found myself in the immobilizer boat. I have a nice pretty new dash installed after an airbag deployment, now I can't start the dang thing and the immobilizer and brake lights flash at me insistently. Two odd things no one has mentioned, my windows were down at the time I was putting the dash in (which turned out to be a poor choice when it started to rain), oddly enough I could not put them up, even with the ignition turned on, using the door switches. The locks worked with the door switches, but not the windows. Just by chance I stuck the key in the door lock (turning and holding to lock the doors) and the windows went up like they normally would. The other oddity is that the key fob (<- spelling maybe) will lock and unlock the doors.

I tried the "reset" procedure described above, but I am wondering if you should turn the ignition switch back off between steps 3 and 4, before hooking the battery back up?

Granted it was in a hurry this morning (in the drizzle) that I disconnected the battery and attempted to short the hot and ground (they wouldn't reach each other so I attempted to use a ratchet between the two), but had no luck. I'll try again this evening.

Also, is there a write up on re-pairing the instrument cluster with the ECU using VCDS?

Thanks in advance!

The last sentence is the key here.
I do not think you can pair it with VCDS.
This might be dealer only to do the pairing (pretty sure), or have a tuner to delete the immobilizer function in the ECU.

Perhaps someone more knowledgeable will chime in here.

MrGutWrench posted "I'm surprized that the VCDS (nee VAG-Com) reset doesn't work for you", which led me to believe VCDS is capable of resetting the link between the ecu and immobilizer. This has me be-muddled given the key fob will lock and unlock the door, yet won't start the car. Doesn't the fob pass the same code?

I've removed the battery terminals and shorted them out for close to a minute or more, turned the key to the off position and then reconnected the battery, then attempted to restart it ... I get the same immobilizer response - naada thing (0.5 sec start/flashing immobilizer code). VCDS software/cable on the way, maybe something will standout beyond what I already don't know.

I'm going to disconnect the battery, remove and re-seat the connectors on the back of the instrument cluster, short the battery terminals with the key on, turn the key off, reconnect the battery and try again this evening.

Maybe I'll add cussing, ranting and raving to my troubleshooting ... ?

Any and all suggestions appreciated.

The key fob has three different important attributes. Key pattern, RFID chip, and RF control transmitter.

The RF control transmitter is what sends out signals when you push buttons. VCDS can match this up so it will work.

The RFID chip in the key responds to a sensor near the ignition key slot, identifying itself to the instrument cluster. The instrument cluster then checks with the ECU, if all three match, the engine runs. If not it quickly shuts down due to the immobilizer.

What exactly did you replace?

If you have replaced either the ECU, a key, or the instrument cluster, then you have immobilizer issues.

The VCDS can pair a key fob radio signal to the door locks.
It cannot match up the instrument cluster, RFID chip in the key, and ECU - the immobilizer.

This must be done by a dealer.

The other option is having the immobilizer deleted by a tuner.

DanG144 said:

What exactly did you replace?

Click to expand...

Literally the dash itself, with vents, headlight/dimmer switch and passenger side airbag.

I'll bet you did not get the sensing coil wires hooked back up, or you broke a wire.

The sensing coil is built around the key slot.

You did not replace the instrument panel?

DanG144 said:

I'll bet you did not get the sensing coil wires hooked back up, or you broke a wire.

The sensing coil is built around the key slot.

You did not replace the instrument panel?

Click to expand...

It wasn't necessary to take the steering column apart to remove the steering wheel/drivers' airbag ... so the ignition key lock was never touched.

The original instrument panel was re-used (the dash came out of a gasser, its instrument panel naturally wouldn't work).

This evening I dropped my star bit down in behind the lower half of the dash and didn't get to remove the instrument panel, I hope to try again tomorrow after work. I just seriously dread having to take my car to the dealer to get this corrected. I just had the timing belt changed, dash and airbag replaced, was fixing to replace my headliner and shocks ... it it weren't for my love of the ALH, if I have to toss $500 more in on top of this it makes me sorta wish I'd used all that money on a down payment of a new Jetta TDI

Last time I ran into an immobilizer issue, I came across a post that recommended turning the key to on and leaving it for about 15 minutes. I spent 45 minutes in a parking lot with my immobilizer light blinking and not letting me start the car before I tried this.

If I remember right the light went from blinking to either solid on or off and then the car started right up and has only stopped me from starting it once or twice in the last few weeks.

Strykeviper said:

Last time I ran into an immobilizer issue, I came across a post that recommended turning the key to on and leaving it for about 15 minutes.

Click to expand...

Oddly as it may sound ... I don't think the ignition has been on for more than a few moments at a time. This solution will be at the TOP of my list when I get home!

... then I'll dig the bits out I dropped into the lower dash out.

I'm up and running again. My steps were:

• disconnect battery
• short the hot with the ground
• turn ignition switch on
• remove instrument cluster and disconnect both electrical cables
• reseat connectors into the instrument cluster
• turn ignition switch off
• reconnect battery (total time of about 15 minutes disconnected as I had to fish the two aforementioned torx bits out of the dash)
• turn ignition switch on (with anticipation of waiting ~15+ minutes)
• ... immobilizer light goes out. I turn the ignition switch off and back one again and the immobilizer light stays out. Woohoo! Car starts and I'm back on the road.

I'm leaning towards the thought that one of the two connectors were not seated fully even though they were locked into place.
Many thanks for everyone that responded. The only troubleshooting step not performed was the utterance of profanity ... but I was close. Really close.

I have the same issue of start for a few seconds and shut off. it does it randomly. hot & cold, wet & dry. I didn't see the immo light come on. After 2 trys i give it a little throttle and start. I hold the RPMs at 2500 for 2 sec then leave off and the car stays running. it only shut off on me once reving, but i dont think i held it long enough. what could be causing this?