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Discussion Starter #1
A few months back my cherry wagon started popping codes. I replaced front and back O2 sensors and all was well for a while. When the same codes [as well as others] started popping. I took it to my mechanic and he kept it for a few days running it and clearing codes. He advised me to take it to the dealer. The dealer gave me a tongue lashing about using aftermarket parts, replaced the O2 sensors and gave me a $1300 bill. By the time I got home the CEL was on and you guessed it - same codes. Back to the dealer for two weeks [fortunately my 96 Jetta is bulletproof pushing 200K!]. Finally they called me stating that the ECU was shot. I said OK how much? Their answer: We can't fix it. The reason: VW no longer makes the part. I'm going to skip the conversation that followed because it was, shall we say, unpleasant - they charged me an additional $150 to correct their original misdiagnosis. I hopped on line hoping someone had a unit in stock. I found two but they turned out to be phantoms - item never removed from online catalog. I DID find a new matching one in China for $100 so I bought it. Dealer won't install it.
As I see it I have 3 options:
1. Replace the ECU with the new part from China
2. Replace the ECU with a used part - I found LOTS of those with the correct P/N
3. Send the original ECU out to one of the places that repair them

**I have the Ross VCDS and I was able to retrieve the immobilizer code [I think it's stored in the cluster on this version] and I'm pretty sure I have the radio code [I found a piece of paper taped to the spare tire well].

I'd be interested in thoughts concerning a decision on my options. I'm also interested in a referral for one of the repair companies as many of them [all?] have dismal reviews.
And one more question: can I pull the thing without disconnecting the battery? I've seen contradictory advice on this.
Any other pitfalls of which I need to be aware?
THANKS!!
102413
 

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Discussion Starter #3
That's the thing that really got me about the dealer. This is a beauty of a car. The interior is perfect, loses zero coolant, It's got a tiny leak from the valve cover - $4 and a little work when the weather clears up. Otherwise it's tight. Runs like a champ. What do they want me to do junk it?

Your idea is quite tempting and I'll add it to my list. It's not too much more than getting the ECU serviced and I assume they'll disable the immobilizer.
Thanks!
 

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Don't assume they will disable the immo. Ask and verify as not all companies do. You can usually find local companies that will "tune" the ECU as well as remove the immo. The extra power is well worth it.
 
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VCDS cannot retrieve the immobiliser code.
I would suggest a used ECU with the same part number, or get your ECU repaired.
In either case you would need to get the immobiliser de-activated.
Or transport the car to a dealer or VW authorised locksmith to get the immobiliser activated for all keys.

You should never disconnect or connect any of the electronic equipment (especially the ECU) without first disconnecting the battery.
 

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Discussion Starter #6
VCDS cannot retrieve the immobiliser code.
I would suggest a used ECU with the same part number, or get your ECU repaired.
In either case you would need to get the immobiliser de-activated.
Or transport the car to a dealer or VW authorised locksmith to get the immobiliser activated for all keys.

You should never disconnect or connect any of the electronic equipment (especially the ECU) without first disconnecting the battery.
Thanks Tom
The VCDS manual describes in great detail procedures for retrieving the immobilizer ID and PIN and then transferring that to either a new or used ECU and also to match the keys. It doesn't look easy but it's not rocket science either. Are you saying that it doesn't work? The fumble butt dealer is out of the question but I do see that it would be easier to take it somewhere. If the dealer didn't already rob me of $1500.00 I would be more inclined to go that route.

I was VERY suspicious of posts on this site claiming that it was OK to remove the ECU without disconnecting the battery.
 

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Discussion Starter #7
Don't assume they will disable the immo. Ask and verify as not all companies do. You can usually find local companies that will "tune" the ECU as well as remove the immo. The extra power is well worth it.
Good advice PZ.
 

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The VCDS manual describes in great detail procedures for retrieving the immobilizer ID and PIN and then transferring that to either a new or used ECU and also to match the keys.
What VCDS manual describes this? Can you post a link? Last I looked the manual had many instructions for this but it required that the user already knew the immobilizer PIN or the SKC.
 

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Hmmmm, that might explain my confusion. The manual shows how to retrieve the 14 digit immob ID but then when doing the ECU swap it says to enter the 4 digit PIN as a 5 digit number (first digit = 0). That is how I remember doing mine and I think the 4 digit number they are referring to is the SKC (secret key code). I don't think VCDS can retrieve that and I don't know if the 14 digit immobilizer ID can be used in its place. Let us know if you get it to work since I don't think I've heard of anyone being able to do with with VCDS only.
 

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Hey Low
I thought it was here and I did retrieve the immobilizer ID when I first got the VCDS system. I have not yet taken a deep dive into the instructions.
Just giving that Ross-Tech page a quick look seems to say that VCDS can retrieve the SKC from the cluster and the ECU. But the video link at the bottom of the page states at the beginning that VCDS cannot do that. I would believe the video. I bought an XTool VAG401 for the specific purpose of getting at those SKCs.

If my curiosity gets the best of me, I might try the VCDS route and let you all know my results. But I doubt I will be successful. VCDS, being a quasi-OEM product, isn't allowed/authorized to get at this info.
 

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Discussion Starter #12
Hmmmm, that might explain my confusion. The manual shows how to retrieve the 14 digit immob ID but then when doing the ECU swap it says to enter the 4 digit PIN as a 5 digit number (first digit = 0). That is how I remember doing mine and I think the 4 digit number they are referring to is the SKC (secret key code). I don't think VCDS can retrieve that and I don't know if the 14 digit immobilizer ID can be used in its place. Let us know if you get it to work since I don't think I've heard of anyone being able to do with with VCDS only.
I'm just as confused as you are. Why would the Ross folks go through all those instructions in the VCDS manual if you can't do the job that way? Do I have this part right: The SKC and the "PIN" are the same thing?

But Low just so you know this is REALLY helpful and moving me closer to figuring out if I can do this myself. I'm starting to understand how much more complicated the Passat is compared to my MK3 Jetta!
 

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Just giving that Ross-Tech page a quick look seems to say that VCDS can retrieve the SKC from the cluster and the ECU. But the video link at the bottom of the page states at the beginning that VCDS cannot do that. I would believe the video. I bought an XTool VAG401 for the specific purpose of getting at those SKCs.

If my curiosity gets the best of me, I might try the VCDS route and let you all know my results. But I doubt I will be successful. VCDS, being a quasi-OEM product, isn't allowed/authorized to get at this info.
Thanks Tort, I'm rooting for your curiosity because that answer will be a HUGE help in making my decision. I'm going to do some more research too. All of this is REALLY helpful. THANKS!
 

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My understanding from using the Xtool is that there are several PINs in the car. I don't think they are all the same but maybe Tortelious can check if he plugs into his car. I remember one PIN for the cluster and one for the ECM, or something like that. It's weird that the SKC has such a distinct name but I had to replace a blown ECM and IIRC, I got the PIN from the ECM (which I think is the SKC since it works with VCDS as shown in the link) using the Xtool and then I was able to replace/reprogram the ECM using VCDS and the instructions shown in the link above.

I've heard even dealers can't or won't retrieve the SKC anymore but they can connect the car to a central data base somehow over the internet and that allows them to re-program the ECM/cluster/stereo/ whatever.
 

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Discussion Starter #15
My understanding from using the Xtool is that there are several PINs in the car. I don't think they are all the same but maybe Tortelious can check if he plugs into his car. I remember one PIN for the cluster and one for the ECM, or something like that. It's weird that the SKC has such a distinct name but I had to replace a blown ECM and IIRC, I got the PIN from the ECM (which I think is the SKC since it works with VCDS as shown in the link) using the Xtool and then I was able to replace/reprogram the ECM using VCDS and the instructions shown in the link above.

I've heard even dealers can't or won't retrieve the SKC anymore but they can connect the car to a central data base somehow over the internet and that allows them to re-program the ECM/cluster/stereo/ whatever.
That's why I took it to the dealer on my mechanic's advice. They won't touch it. If I traded it in how long do you think it would take them to fix it and put it on the lot for sale?
 

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In reviewing all the videos I saved covering this SKC retrieval, I see that most are now private/un-viewable.
So either write down the procedure or save the video to your computer somehow in case this one disappears too.

I won't make any videos, but I might make step-by-step instructions with images if/when I mess with it again.:sneaky:
 

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In reviewing all the videos I saved covering this SKC retrieval, I see that most are now private/un-viewable.
So either write down the procedure or save the video to your computer somehow in case this one disappears too.

I won't make any videos, but I might make step-by-step instructions with images if/when I mess with it again.:sneaky:
Thanks Tort. I downloaded it. I'll take a dive into it in the next few days.
 

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I'm not a professional VW mechanic (and neither is VW obviously from this experience and my past experience--what is a professional? Someone paid to do a job in the least amount of time in order to make the highest profit), but as one with I'm betting one of the highest mileage V6's on the road (345K and running stronger than ever) and owing a few around here (Yes Andreas P, she's back!, and I thank you), here is my humble opinion:

If it is running relatively well but with O2 codes and some possible misfires, there is probably nothing wrong with your ECU. You do not state your mileage nor the codes, but my experience since 80K-345K with O2 codes says you may be using a little oil. Mine used about 1-1.5 qts every 3000-3500 miles since 80K, something VW says is in spec. The top end is the weak link in the V6 (though I think it's the strongest of the 3 available).

My suspicions with mine are that I poisoned my cats due to the oil usage. Never showed a blue plume, though I was always in the driver's seat. I replaced mine (don't buy Bosals--another story) w/ VW cats and ended up poisoning them 10-15K later.

My fix was to put a spacer in front of the rear O2 sensors.


The spacers are stainless, pretty unobtrusive, and I've sailed through MD emissions ever since. You seem to be in PA, don't know their laws, but you're not in CA. I don't have a vag-com, but understand there's a way to turn off the rear O2 sensors with it, or do something with a resistor network to desense the rear O2 sensors. The spacers with the middle sized jetting worked for me.

Don't junk it, and don't take what VW said as gospel. When mine died years ago, it was only a couple desperate attempts away from the junkyard. I was out of bandwidth, and let VW look at mine and two dealers couldn't fix it. One said probably lifters. Another said probably injectors. And between the 2, I spent about 1800 bucks with NO improvement (in fact it was worse after the first--they left off injector wires!) I replaced both, and that had nothing to do with my problem. That ended up being worn shoes on the CCT's (variable cam chain tensioners). I'm currently running with the spacers, a "stock" VW exhaust with NO catalyst in the converters (one of the desperate attempts, and unfortunately rather permanant), and I throw NO codes.

Again, I'm not the last word, but I've got a bit of experience w/ the V6 without the aid of a Vag-Comm. I vote to leave the ECU alone. Mine's never been a problem though it got a lot of suspicion more than a few times. If you mess with one, do it on a spare from the wreckers.

I wish you well. Best of luck.
 

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Oops, you're a 1.8. But my bet is it is NOT the ECU, and going off in that direction w/ the pitfalls of the immobilizer is a miscue and distraction from the real trouble. Just my humble.
 

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Discussion Starter #20
I'm not a professional VW mechanic (and neither is VW obviously from this experience and my past experience--what is a professional? Someone paid to do a job in the least amount of time in order to make the highest profit), but as one with I'm betting one of the highest mileage V6's on the road (345K and running stronger than ever) and owing a few around here (Yes Andreas P, she's back!, and I thank you), here is my humble opinion:

If it is running relatively well but with O2 codes and some possible misfires, there is probably nothing wrong with your ECU. You do not state your mileage nor the codes, but my experience since 80K-345K with O2 codes says you may be using a little oil. Mine used about 1-1.5 qts every 3000-3500 miles since 80K, something VW says is in spec. The top end is the weak link in the V6 (though I think it's the strongest of the 3 available).

My suspicions with mine are that I poisoned my cats due to the oil usage. Never showed a blue plume, though I was always in the driver's seat. I replaced mine (don't buy Bosals--another story) w/ VW cats and ended up poisoning them 10-15K later.

My fix was to put a spacer in front of the rear O2 sensors.


The spacers are stainless, pretty unobtrusive, and I've sailed through MD emissions ever since. You seem to be in PA, don't know their laws, but you're not in CA. I don't have a vag-com, but understand there's a way to turn off the rear O2 sensors with it, or do something with a resistor network to desense the rear O2 sensors. The spacers with the middle sized jetting worked for me.

Don't junk it, and don't take what VW said as gospel. When mine died years ago, it was only a couple desperate attempts away from the junkyard. I was out of bandwidth, and let VW look at mine and two dealers couldn't fix it. One said probably lifters. Another said probably injectors. And between the 2, I spent about 1800 bucks with NO improvement (in fact it was worse after the first--they left off injector wires!) I replaced both, and that had nothing to do with my problem. That ended up being worn shoes on the CCT's (variable cam chain tensioners). I'm currently running with the spacers, a "stock" VW exhaust with NO catalyst in the converters (one of the desperate attempts, and unfortunately rather permanant), and I throw NO codes.

Again, I'm not the last word, but I've got a bit of experience w/ the V6 without the aid of a Vag-Comm. I vote to leave the ECU alone. Mine's never been a problem though it got a lot of suspicion more than a few times. If you mess with one, do it on a spare from the wreckers.

I wish you well. Best of luck.
Thanks Kroz and I apologize that I didn't lay out everything clearly. It's NOT running well. I'm not going through this to satisfy the OBD Gods. That CEL doesn't bother me if the thing is running perfectly. Nor is inspection a problem. The car is pretty much disabled. Cylinder 3 is a constant miss not an occasional misfire. One of the things they did was to hotwire the injector on that cylinder and everything checked out. Hook it back up to the ECU and the misfire returns. The odometer reads 126K. There's nothing wrong with the O2 sensors and I'm convinced there never was. I replaced them once myself and the codes kept coming and the dealer replaced them again and the codes came immediately. I'm pretty convinced they're right about the ECU because almost all other possibilities have been eliminated. I appreciate the advice: I have zero intention of junking this car or trading it in and I don't take ANYONE'S word as Gospel let alone the dealer. It's looking like I won't be able to do the job myself though and that sucks but there are some good solutions that won't break me. Thanks again!
 
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