2010 Jetta ECU replacement questions... need guru help!

DriverJon

Veteran Member
Joined
Jan 22, 2011
Location
Irvine, CA
TDI
2010 Jetta TDI, 6M
I want to know if there's anything in the process of replacing an ECU that can "go wrong", "not get done", etc, that might cause problems with the car.

Some history:
Had issue with the turbo actuator a while ago... the dreaded code, going into limp mode. Determined on my own that it really was the actuator not holding vacuum. Ended up thinking it was just too much hassle to do myself, sent to independent shop. A little pricey but shop fixed OK.

Fast forward 3mo or so, got a couple of limp mode events again, got out the HEX-COM and yes, actuator issue again. Hmm... Figured it's likely a 13yr old hose that developed a crack, or a wire got pulled on, etc.. should be an easy fix. Shop spends a while, says "we traced everything, it was the control wire for the turbo that had 3.5V on it rather than 0V, and it was like that on the pin of the ECU so its your ECU". Not very happy... how could I check up on that diagnosis? So, I need a new ECU, final price $2000. (included a new battery, that I knew was on the way out)

Took a month, with diagnosing, waiting for computer to be delivered, then glow plug problems, due to them not "getting programmed properly", waiting for all the codes to get reset before car can be declared fixed, (?) etc.

Cruise control did not work after I picked it up. Also a diesel leak started, 3-4 days after I got it back. Was going to get them to fix the CC, and maybe look at the diesel leak. I'll have a thread asking about the leak in the aux fuel pump area somewhere else. They want $895 for that, pump, hoses and have to change the fuel filter, of course, that container has fuel on it.

Anyway, sorry for the lengthy woes... I want to know if it's a straightforward process to swap out an ECU, or is there a lot of particular reprogramming and re associating of parts that needs to be done? My fear is, they don't know what they're doing, and botch up things in the car that may do damage later. I know it could be possible that they ran a process, and with low battery voltage it might not have been fully successful, and maybe the second try with a new battery would be ok. But if there's a chance of problems, I want to know, and try to determine if my main transportation is going to be OK in the future.
 

Rx7145

Veteran Member
Joined
May 21, 2017
Location
Ohio
TDI
2006 Jetta BRM
The engine control module is coded to the car either needs to be shipped to a vender like karma or taken to the dealer as far as I know. It’s not an easy or straightforward process.
 

DriverJon

Veteran Member
Joined
Jan 22, 2011
Location
Irvine, CA
TDI
2010 Jetta TDI, 6M
My question is, could they have screwed up getting all the car components' info into it, or does it work like that?

I'm concerned that the glow plugs weren't "properly programmed" (?) or whatever, and they had to work further. Maybe it was low battery voltage, and the whole process is automated with no need to save info from the old computer? I don't know, and they weren't very forthcoming with an answer to that question.

I want to know if I can determine everything is OK, or I have to take their word for it. They still haven't officially signed off on it, but released it to me to drive around till "all the codes reset". After I now have to fix or pay an additional $900 for fixing the new diesel leak, THEN they might address whether there's computer issues after their swap.
 

DriverJon

Veteran Member
Joined
Jan 22, 2011
Location
Irvine, CA
TDI
2010 Jetta TDI, 6M
Am I TL;DR again?

So, any one have comment on how easy is it to screw up replacing ECU? What I check for?
 

DriverJon

Veteran Member
Joined
Jan 22, 2011
Location
Irvine, CA
TDI
2010 Jetta TDI, 6M
And, anyone wanna buy my old ECU? 163K miles young! $10 extra and I'll resolder the broke turbo pin...
 

Rx7145

Veteran Member
Joined
May 21, 2017
Location
Ohio
TDI
2006 Jetta BRM
Sorry, I can’t be much help hopefully oilhammer or Frank06 will jump in. I just don’t know the answer to your questions.
 

325_Guy

Veteran Member
Joined
Jun 21, 2011
Location
West Central Texas
TDI
MkV Jetta
Any shop that can do immo reprogramming would certainly be able to reset any stored codes and return the vehicle to you without a lit CEL. Also not understanding how a broken pin on the ECM caused an unexpected high voltage. And supposing it was a broken pin, which mysteriously broke while in the dense multipin connector (it can happen I suppose), but you're able to fix it, why didn't the shop just re-solder it instead of charging $2K for a replacement part?

Tbh it just sounds like a basket case at this point and I think your fear is correct that the shop has no idea what they're doing. Has this shop worked on TDIs or VWs in the past?

I'm also surprised they gave it back to you to drive with it dumping fuel on the ground.
 
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DriverJon

Veteran Member
Joined
Jan 22, 2011
Location
Irvine, CA
TDI
2010 Jetta TDI, 6M
They never called it a broken pin, said it should pull to gnd and the faulty 3.5V was traced to coming out of computer. No wiring fault.

It wasn't leaking (that I'd noticed yet) when they gave it back, it started 3-4 days after that. They now say they can't work on the other problems, till the leak is fixed.

They refused my electronics guy opinion if likely internal cracked solder joint or whatever, I could open the computer and possibly fix. Then they couldn't guarantee their work...
 
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Bldenny

Member
Joined
Oct 30, 2021
Location
Missiouri
TDI
2006 1.9L A5 5 Speed
I've done complete swaps before. Mk5 jetta brm. Ecu, instrument cluster and key are all coded together. Getting the ecu out is a pain, but its plug and play after that
 
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