2002 BMW E46 IT Wagon just changed the battery from the original Bosch, now transmission error code and slippage? Could it be a fried sensor?

Hello Everyone,

My baby, 2002 BMW E46 325i Wagon (automatic) with over 250.000, miles on it is sick.  My original Bosch battery died last week and my husband purchased a quickie Wal-mart replacement battery same supposed thing :(, anyway I'm thinking it is not the same thing and neither is he. It was really cold following the battery install and I noticed the shifting was a bit rough, but blamed it on the cold weather. This past Friday it was in the 50's, and I was driving it and same rough shifting then the transmission error light came on and went into limp mode.  I pulled into a parking lot, parked it and turned off the car.  I waited there (while I called my Husband) for a few minutes then restarted it to try and get it to my Husband's office about 3 miles away. It was fussing and rpms going a bit high (no red lines) but I made it. After all of that here's my question: since this car is picky electronically, ( I recently plugged a stupid cheap I-pod adapter with blue tooth in the cigarette port and it fried my blower module! I proudly fixed that myself :) ) could it be that a module or sensor is messed up from the sub par battery? I have done the transmission reset. But not exactly sure if I did it correctly for this car.  I turned the key to accessory, held the gas to the floor for 30 seconds then turned it off, then restarted and drove it. It did not seem to help. What do you think?  I appreciate your input!






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MBFanatic made a comment.
6 months ago

I don't think the quality of the battery is causing the transmission problems. With that said, you may want to do battery registration if you want the battery to last. Most 2002 and newer models need it and yours may do as well. Not 100% sure. Not registering the battery should NOT cause these kind of problems.

You may have an issue with the mechatronic valve body. Can you read the codes from the transmission module (EGS)? It requires a scanner that can pull codes from the transmission module. The code readers at autozone and advance auto parts don't read transmission codes.

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abusufyan made a comment.
6 months ago

Hi! have your issue been resolved?


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