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How to access ECM & TCM on 850, S70, V70, XC70, C70

Looking to access ECM & TCM?

How to remove ECU and TCU Modules

ECU access tutorial

MVS Forum member gchelidze tells us in text and (24!) photos how to access your ECU and TCU modules from under your Volvo 850, S70, V70, XC70, C70’s hood. He writes:

“WARNING: I have done this procedure twice – once with battery lines connected and once with negative line disconnted. I didn’t see any difference. However I would disconnect it if I have to do it again just in case. Do at your own risk! If you decide to disconnect a negative line from a battery, make sure you have a your audio system unlock code. You will be prompted for it after you connect a battery back again.”

1. Tools you’ll need: hex socket M10, screwdriver, thin metal stick
2. Location: TCM is located in a black rectangular box at front right side with yellow sticker on it

DIY access/remove ECM & TCM on 850, S70, V70, XC70, C70 Looking to access ECM & TCM?

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My 2001 xc70 the blower fan will not turn off or change speed even with the key off and out. The air conditioner won’t come on ether, but I know that it dose work. This all happen all at the same time. What do you think about this problem. Thanks Woody

I own a 2001 volvo s40 and i really need to know where the transmissin control module located people keep sayin its on theright side of the car buti never see a black boxplese tell where it is

I would like to no how to go at a problem I’m having after a mechanic replaced my radiator . It is now leaking transmission fluid and if your standing infront of the car facing the windshield it appears to be leaking from the bottom left side my guess is the mechanic didnt use new clips and o rings could this be the problem? This is our first volvo and yes I am new to this . However , i am mechanically inclined not a pro but can listen and learn alot from you guys. It a[[ears that its leaking from the bottom front rolling down sligthly and dripping off the bumper on the drivers side . i checked the top and its not there but the bottom is really saturated does transmission fluid pass into the radiator through the bottom hose? I have a 2004 v70 2,5 T Thank you for any help Stressed out in Southcarolina

I have followed your instructions for removal and although I can feel the ECM is looose after sliding the pink holders back as far as they will go, I cannot pull the ECM out. I am afraid if I pull any harder something will break. Any suggestions?

I just moved to Oregon from Nevada, my 97 850 T5 is acting up. I found a 97 T5 wagon being parted out here in Oregon. I cannot remember what VIN #’s tell me that it is a T5. My manual is packed in storage. Can anyone tell me what #’s to verify it is a T5?

I didnt think opening up and removing the ECM and TCU needed a 24 photo DIY. But hey, I guess everybody has to start somewhere and we were all newbies at one time.
Very in-depth this can be an example of a thorough contribution. Thanks. This should be a DIY on a DIY.

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