Immobilizer Question

[HeyCrutch]

Having an immobilizer issue with the 2002 EVC.

Everything was fine until today. Went to crank the van and heard the immobilizer signal and the dash lights went blank. Of the 2 chip keys that I have for this van, one of them gave me trouble a couple of months ago, so I had switched to the second one. Now it seems to have given up.

Ironically in today's mail I received two 219H Key blanks that I intended to get cut & coded for the 2002 EVC and the 2003 Weekender. Wanted regular style keys b/c I've read that if the Flip Key versions happens to "close" when it's in the ignition, it can cause issues with the immobilizer (and given the age of those flip keys, they can easily close on themselves).

----

One of the supposed potential faults can be a low battery in the key ... but I'm wondering specifically WHICH battery ...

I've only got the Flip Keys Key FOBs, the kind with the flip out key section that also has an attached Lock/Unlock button section (it's actually 2 separate pieces that fit together).

I know how to replace the battery in the Lock/Unlock section of the FOB, but I'm thinking that only controls the radio transmitter for Remote Entry. I don't think the Lock/Unlock section contains the immobilizer chip that is critical to the operation of VWs.

I'm assuming that the chip that communicates with the Immoblizer system is in the Flip Out Key section of the FOB ... but I don't know if there's a battery that can be changed for that section of the FOB.

It may be possible that the one battery powers both, but I really don't think so, as connection slides of the 2 pieces look to be only plastic.

I know there are other things that can cause the Immoblizer System to kill the ignition ... just trying to start with the low hanging fruit first, which I would assume is keys.
_________________
-2003 EV MV Wk - Forest - 51k
-2002 EV Camper - Ghost - 82k
-2003 EV GLS - Fluffhead - 176k

-1997 EVC - 12vVR6 (SOLD 5/2025)

[EuroTec]

If you can't get it working you can do an immobilizer delete.

It's a very common mod on VWs. The immobilizer is a PITA!!

Daniel at All German Performance on Hendersonville Road should be able to do a delete. I used to work there.
828-483-9007
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If it ain't broke, don't fix it!

[bikes!]

The battery in the key is for the remote lock/unlock only. The immo chip communicates passively via an antenna at the ignition switch.

If you have VCDS, you can read the faults in modules 1 (engine) and 25 (immo). Typical for the engine module to show "16706 - Engine Speed Sensor (G28)" fault and immo to show "01176 - Key 65-10 - Unauthorized - Intermittent" fault. Resetting them may allow you to restart. Checking the connectors at ECU and immo modules are clean and free from corrosion is a next good step.

I had the immo disabled on my 2002 van a few years ago. It fires right up every time now. I had a guy in Mass do the immo-delete for me, but if there's someone in Asheville, that is much easier. In my case, I pulled the ECU and mailed it from CA to MA. A bit stressful waiting for it to return.
_________________
VWs past: 66 Kombi, 76 Westfalia Camper, 17 GTI; present: 02 Eurovan MVW, 17 Alltrack SEL & 19 Golf R

[HeyCrutch]

[HeyCrutch]

[HeyCrutch]

Just posting this as a reference for posterity (for anyone who might read this thread now or later).

From the VW Service Training Self-Study Program 890293 - Immobilizer Systems:

- 1999-2000 Eurovans had Immobilizer II Gen 2
- 2001-2003 Eurovans had Immobilizer II Gen 3

[From personal experience I can attest that the 1997 Eiurovan did not have an immobilizer system at all.]

"Immobilizer II uses a randomly-generated code to disable the fuel pump until the correct key is inserted.

The Immobilizer authentication process begins with the vehicle key and the induction coil.

When the vehicle key is inserted into the ignition cylinder and rotated to the On position, a signal is sent from an induction coil that energizes the electronic transponder in the key. The electronic transponder in the key responds to the induction coil with a fixed code signal.

The induction coil n the ignition cylinder receives and forwards the signal to the Immobilizer Control Module. If the fixed code signal sent by the key matches the code stored in the Immobilizer Control Module (ICM), the variable code transmission starts.

This step only recognizes the key as coded to the vehicle.

As soon as the ICM recognizes the key, it generates a random number and sends it to the key. The vehicle key and ICM then perform an algorithmic calculation on the number. After applying this algorithmic calculation, the vehicle key sends the results to the ICM.

The ICM compares the number it calculated to the number calculated by the vehicle key. If the numbers match, the ICM sends a signal to the Engine Control Module (ECM) J220 to start the engine.

The entire process takes places nearly instantaneously."


Components of Immobilizer II -
- Anti-Theft Immobilizer Warning System (on some models)
- Anti-Theft Immobilizer Reading Coil D2 (D3)
- Anti-Theft Immobilizer Control Module J362

_________________
-2003 EV MV Wk - Forest - 51k
-2002 EV Camper - Ghost - 82k
-2003 EV GLS - Fluffhead - 176k

-1997 EVC - 12vVR6 (SOLD 5/2025)

[bikes!]

[HeyCrutch]

[HeyCrutch]

5:00 PM Update -

It was bothering me that everything I've been reading about the Immobilizer II system indicates that the van should start and if the key and coil don't do their thing, the system cuts the fuel pump and the van turns off.

But it shouldn't kill ALL dash lights ... which was what was happening with my van. I've been under the misapprehension that when the immobilizer system kicked in that it killed EVERYTHING - ie shut down the electrical system entirely. My understanding after reading the service training is that it should not kill all power.

Now I'm sure most of you more learned that me woulld have said immediately that when the dash lights went dead that I probably just had a bad starter battery. But in my defense, I'm pretty new to the whole Immobilizer System (just with this new 2002 van that I bought late summer - the 1997 van I've had for a few years doesn't have it) ... so I'm learning. A Lot. (Pause to thank everyone here that helps out with that education)

So, I was able to jump start the van. But not easily. With one key, the Immobilizer would immediately shut the engine off (but not kill lights). Tried the second key and it finally got it cranked. After running the van for 5 mins and turning if off, it failed to start again.

The battery isn't that old but we have had a very cold late fall here in Asheville, and the van doesn't get run much, so it's possible it's dead.

We've got wintry mix happening here right now so I'll swap out a battery from one of the other vans tomorrow, and probably get it tested at OReilly's as well. Will report back to close the loop.

Based on one of the keys not satisfying the Immoblizer System, I'm assuming that key is bad. If bad, can it just be put back through the re-code process or is it junk? I know I've read "you code the van, not the key" but that must mean the van's ICM and ECM can keep track of multiple keys that will work to start the engine.

More importantly, I love the idea of getting the ECM mod mentioned above to by-pass / delete the immobilizer altogether. Anytime the van has issues starting, it becomes way more confusing trying to diagnose than it ought to be (or than I would like it). As evidence here ... if this turns out to be a bad battery, I've been spinning my wheels on the Immobilizer System erroneously.

Add induction coils to the list of things I need to learn more about. Fascinating stuff.

Of course I am fairly certain I've got one bad key -- which absolutely IS an immobilizer issue - so I've locked it away for now.
_________________
-2003 EV MV Wk - Forest - 51k
-2002 EV Camper - Ghost - 82k
-2003 EV GLS - Fluffhead - 176k

-1997 EVC - 12vVR6 (SOLD 5/2025)

[Endopotential]

Just chiming in what little I know, from having the ECU on my '02 Weekender get fried this summer. You can look up my posts for the painful details if you want.

I can confirm that yes, if the two won't match the car will start for a few seconds and then just die. This is what happened when the new non-immobilizer deleted ECU wasn't recognized by the system. Trying to program the SKC into the new ECU was a headache. I don't remember what happened with the dash lights.
Though starting off with a strong battery would help determine an easy fix.

I ended up having to sweet talk my way to the back door of a dealership to sort it out, as up front all the places in SF refuse to work on our 20yo cars. They definitely did something to reprogram the keys themselves.
It sounds like you've got some good resources in NC, so best of luck.

[kourt]

This vendor recently quoted me $145 plus shipping to do an immobilizer delete on my 2001 Eurovan ECU.

https://www.advancedcarelectronics.com

I haven't done it yet, just posting what I was quoted.

I am inclined to wait until my van is exempt from emissions (2026 in my county in Texas), and then send in my ECU to get both the immobilizer and the secondary air injection system deleted from my ECU.

kourt

[bikes!]

Advanced Car Electronics was the other company I considered for the immo deletion. The folks who did the work for me are currently taking a break. Hopefully they resume service. They were easy to communicate with and I have had no dramas with ECU pairing or immo preventing the van from starting. Butt dyno says the van runs more smoothly, but I have no data to back that up.

https://varpartsma.com
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VWs past: 66 Kombi, 76 Westfalia Camper, 17 GTI; present: 02 Eurovan MVW, 17 Alltrack SEL & 19 Golf R

[HeyCrutch]

Following Day Update:

Turns out the NAPA battery was my issue the entire time ... going all the way back to the first time I encountered what I thought was an Immobilizer issue (when I thought one of the keys had gone bad).

Swapped in the AAA battery from one of the other vans on the street and the 2002 EVC started right up with gusto. Let it run for a bit and turned it off. Tried the other key (the one I assumed was bad) and it also started the van with no issues (again, with gusto).

Wanting to see if the NAPA battery that had been in the van was testing as bad, I took it to the nearby NAPA to get it tested. It PASSED as GOOD with sufficient voltage, however the CCAs were in the upper 500 range (585 maybe - I didn't get a printout).

Put that NAPA battery in the 1997 EVC just for kicks and it started that van right up.

So, I'm a bit perplexed. Auto Parts websites do show that the 1997 van's specs only call for 500 CCAs whereas the later vans (2002 and 2003 that I have call for 600 CCAs), yet VW's website recommends one and only one battery for all the vans (1997-2003 that I checked) - 191-915-105-AB-DSP

So, I don't really know what to say except this ...

If you think you are having a starting issue, before chasing your tail with the Immobilizer, consider that it might be an electrical issues (in my case insufficient power coming from the starter battery).

I know there are a host of other components to the starter/ignition electrical system and I'll continue to learn about those, so not ruling out that some other part of that chain can lead to an issue.

I think I'm going to begin treating batteries as a regular maintenance item - replacing it at a regular interval (based on time) rather than just waiting until there's an issue with it.

----------------------

In case anyone wonders about the batteries :


The NAPA battery that was giving me problems:
NAPA The Legend Professional Battery 24 Months Free Replacement
BCI No. 47 650 CCA
- BCI Group Size: 47
- CA 800 A
- CCA 650 A
- DIN Code: H5
- 9.56” W x 688” D x 7.5” H
- 36 lbs
Manufacture date Sep 2023 (not sure of the install date)

The AAA battery that fixed my issues (purchased from a NAPA store)
AAA Premium Battery 36 Months Free Replacement BCI No. 48 730 CCA
- BCI Group Size 48
- CA 900 A
- CCA 730 A
- DIN Code:
- 11” W x 6.88” D x 7.5” H
- 42 lbs
Purchased and installed May 2024 - Mfd Feb 2024.
_________________
-2003 EV MV Wk - Forest - 51k
-2002 EV Camper - Ghost - 82k
-2003 EV GLS - Fluffhead - 176k

-1997 EVC - 12vVR6 (SOLD 5/2025)

[bikes!]

Here’s another thought: check to make sure all of the ground wires are firmly attached to the battery. I replaced the alternator about a year ago (a year after the immo delete) and the battery kept struggling to hold a charge and the voltage at idle was low (12,0V or just above). I blamed the alternator and since the voltage when driving was well above 13V, didn’t think about it much.

Testing the battery showed it was losing ability to recharge. I gave up and replaced the battery and when I was installing the new one, noticed a stray brown wire not connected to anything. Traced it to be a ground for the ECU. Once reconnected, the system voltage at idle was a happy 13,7 ~ 14,2 V. Self induced error, I’m sure I missed that ground wire when replacing the ECU after having the immo deleted.
_________________
VWs past: 66 Kombi, 76 Westfalia Camper, 17 GTI; present: 02 Eurovan MVW, 17 Alltrack SEL & 19 Golf R

[HeyCrutch]

[angel smith]

I am currently having a similar issue with an 03 eurovan Winnebago Vista,
This is a new vehicle to me.
I am NOT getting an audible noise or light on the dash to know if mine has been immobilized. I get a start and shut off immediately.
What is the noise i may hear or the lights to be sure it is the immobilizer?
The battery is new and I have the valet key only. I do not have a VW specific scanner.
Thanks for the help.

[HeyCrutch]

[jjvincent]

When you bought a Eurovan brand new, it came with 5 keys and a PIN tag.

2 Keys have the lock/unlock fob (has immobilizer cjip)
1 Key is a valet key with no fob or battery (has immobilizer chip)
2 Keys are for the glove box in the drivers door (no immobilizer chip)
1 PIN (which is actually important but people just throw them away)

If your EV starts and then shuts down, you need a new battery for the Eurovan (the one under the hood). The immobilizer is very robust but just like on a Cabrio (both have an external immobilizer box as opposed to being integrated into the instrument cluster), they are sensitive to low voltage for starting. Thus why it starts and shuts off in about 1 second.

It will throw a code where it'll be that the start is blocked by immobilizer. There is no need to clear it, just get a new vehicle battery.

[HeyCrutch]

[IdeaNerd]

Thanks @jjvincent and @HeyCrutch for the details and links re: keys. We are missing a few of the "extra" keys, and this fleshes out a number of details that I hadn't got around to researching yet. Thanks!