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Discussion Starter · #1 ·
So my beloved Passat bit the dust , I was coming home and noticed water pooling in my back floorboard, as I panicked a realized what was a happening climbing the hill to my apartments, the car didn鈥檛 have the power to climb, rough shift to reverse and drive out of nowhere, mechanic pulled both ecms and both are corroded, I was able to limp it home because the mechanic couldn鈥檛 find the parts anywhere, my question is do I also need the wiring harnesses for each and do I need to find my exact year make and model. I鈥檓 lookin at about 1000$ If I can find the parts with labor and another question how hard is it gonna be hunting these parts and is there anyway to repair the corrosion to my ecms at all. car violently lurches now and stays parked, so many good parts to waste including TB kit :(
 

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The module your referring to is the TCM (transmission control module) located under the carpet in the front passengers side foot well.
You can take out the passengers seat and pull back the carpet and inspect the wiring harness.
If the large connector has corrosion on it, used replacements are plentiful on the internet.
Pigtail replacements are also available.
eBay is a good source for this part.
You'll need to match the part number to your original TCM module

Here's an example of what's readily available.

102880
 
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So my beloved Passat bit the dust , I was coming home and noticed water pooling in my back floorboard, as I panicked a realized what was a happening climbing the hill to my apartments, the car didn鈥檛 have the power to climb, rough shift to reverse and drive out of nowhere, mechanic pulled both ecms and both are corroded, I was able to limp it home because the mechanic couldn鈥檛 find the parts anywhere, my question is do I also need the wiring harnesses for each and do I need to find my exact year make and model. I鈥檓 lookin at about 1000$ If I can find the parts with labor and another question how hard is it gonna be hunting these parts and is there anyway to repair the corrosion to my ecms at all. car violently lurches now and stays parked, so many good parts to waste including TB kit :(
There is only one ECM (ECU) and that is in the box in the engine compartment, and appears to be working properly.
I guess you are referring to the CCM on the LHS floor and the TCM on the RHS floor.
The following was written for the CCM, but can also be used for the TCM.

Locate and fix source of water ingress.
I suggest you completely unwrap all of the CCM harness and pull the wires apart to find the splices, any corroded splices need
to be cut back, soldered, and covered with marine grade heat shrink tubing. (You might need to add short wires to replace what you cut out)
Also check ground connections (1 on floor and on "A" Pillar), and check CCM/TCM and "A" Pillar connectors.

Have a good look at this link, before you start. (Note: This is a UK car, the CCM is always on the LHS)

This thread attempts to bring together all the problems regarding water ingress and their solutions.
Water Ingress and Solutions
 

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You don't need to remove any seats, just slide them back.
If you are replacing any modules, the part numbers must match exactly.
 

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Discussion Starter · #5 ·
Is this a tough fix for a DIYer the car is otherwise beautiful and runs great with plenty of life only 112k I think the mechanics said he believes the water came from the hood, all he was able to do is pull the modules and put them back he couldn鈥檛 find the part as he told me I would basically need to find my exact car, is this true? Can鈥檛 be a year newer or older, he said the module for the engine and transmission are both roast and don鈥檛 drive the car, thank you guys all for helping a noob put gonna take your advice and attempt to fix or atleast find what I need cheers 馃
 

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If it's just a module change, it's almost literally plug-n-play. Some minor coding would have to be done to make sure the replacement module works correctly with the installed options on your car.

If the harness needs to be cut and all the wires spliced in, that's a bit of a job.
I did it myself a few years back. Took the better part of a day.
 
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Used trans modules are pretty cheap on Ebay, I don't know if they are as picky about the full numbers and letter matching as the ECU is.
 

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Discussion Starter · #8 ·
I鈥檓 gonna try to pull the passenger floorboard and see whats the number I tried starting it and it was dead to the wind any reason this could have happened, last time it ran I lurched it to a halt
 
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