Code U1000

[Max2M35]

So, I just recently replaced the TCM and Valvebody on my 06 35. With the original TCM, it was slipping left and right and having trouble going. Period. Replaced the TCM, and that issue went away and it goes into 1st and 2nd but stays in second. It's also throwing the U1000 code. Might I also add that its a rather violent jolt into 1st and 2nd gear. What might be the issue? Could it be a bad TCM? Or does it need to be programmed? Thanks for any help or advice.

Edit: also, my gear selection screen went away and no manual mode...

[Ilya]

Did you get a user TCM? Or a new one?

[Max2M35]

Did you get a user TCM? Or a new one?

Used... it was kinda process of elimination.

[Ilya]

It's possible you got a dud. You sure you're actual transmission is fine though? But yeah, no M mode and no gear selection screen suggests something electronics wise which could cause the slipping...if the slipping isn't due to the transmission itself.

[Max2M35]

It's possible you got a dud. You sure you're actual transmission is fine though? But yeah, no M mode and no gear selection screen suggests something electronics wise which could cause the slipping...if the slipping isn't due to the transmission itself.

Yea the transmission is fine... crazy thing is, the slippage went away with the used one. But when I put the original in, slippage here and there, even in reverse. It's like something isn't catching and it makes a noise similar to power steering...

[Costee]

It's possible you got a dud... no M mode and no gear selection screen suggests something electronics wise which could cause the slipping...

I'm with you on this. It's electronics. The TCM is either not receiving or transmitting proper signal. A specific code might show up with a scan tool that can read the transmission.

[Max2M35]

Is it worth noting that the original has a crack in the plastic casing? Idk if that's a good or bad thing because I'm sure fluid had been getting in there.

I'll try to find another TCM, hopefully it'll be a good one. If I were to order a "refurbished" unit offline, would that require a dealer visit to program?

[Larz]

You mentioned no manual mode indicated with this TCM. I reckon that means it either is not the correct part (though I'm sure you verified, they probably mis-labeled it or sold a broken one) ... or ... Even better, perhaps you DO have the right part already but it requires programming from the dealer? Seems likely that replacing a TCM would require programming to marry the engine to the gear box.

[ae7456t]

When I had problems with my transmission, I got a U1000 code...My initial issues were transmission related, and had them swap in a new transmission, but used the original Valve Body/TCM...This is when the U1000 popped up, with similar faults to yours (no manual mode, no gear shift indicator showing).

U1000, as I understand it, is some type of communication fault, most likely between your TCM and the rest of the smart parts in the car. In my case, the new transmission had sat outside, and, as a result, the connector plug that "tunnels" through the transmission housing to the TCM had become severely corroded to the point where the pins were crumbling. The fix was a simple as swapping out that connector and wire harness inside the transmission that connects to the TCM, then good as new.

Separately, I have also had experience repairing the TCM itself (due to the P1757 broken solenoid "finger"). From memory, transmission fluid gets all over, around, and in the TCM, so a crack in the plastic housing should not be a problem...More troubling is if the electrical board inside has cracked and a signal is not getting to/from the solenoids. Not sure if you have tried to open the plastic TCM case to inspect the board, but that might give you some more insights, as well.

[Max2M35]

When I had problems with my transmission, I got a U1000 code...My initial issues were transmission related, and had them swap in a new transmission, but used the original Valve Body/TCM...This is when the U1000 popped up, with similar faults to yours (no manual mode, no gear shift indicator showing).

U1000, as I understand it, is some type of communication fault, most likely between your TCM and the rest of the smart parts in the car. In my case, the new transmission had sat outside, and, as a result, the connector plug that "tunnels" through the transmission housing to the TCM had become severely corroded to the point where the pins were crumbling. The fix was a simple as swapping out that connector and wire harness inside the transmission that connects to the TCM, then good as new.

Separately, I have also had experience repairing the TCM itself (due to the P1757 broken solenoid "finger"). From memory, transmission fluid gets all over, around, and in the TCM, so a crack in the plastic housing should not be a problem...More troubling is if the electrical board inside has cracked and a signal is not getting to/from the solenoids. Not sure if you have tried to open the plastic TCM case to inspect the board, but that might give you some more insights, as well.

That makes sense. I thought that might have been the issue when I initially put the used TCM in so I put the old wire harness back in, and nothing changed.

That's where this whole thing started with the p1757 & 1759. Soldered the connection back, made sure it wasn't touching any other pins, and put it all back together. Then, it just started slipping and sounding like a high powered blinder when I drive forward or backwards. It struggles.

I guess my next step is to either source a known good TCM or refurbished, and go from there.

[Max2M35]

You mentioned no manual mode indicated with this TCM. I reckon that means it either is not the correct part (though I'm sure you verified, they probably mis-labeled it or sold a broken one) ... or ... Even better, perhaps you DO have the right part already but it requires programming from the dealer? Seems likely that replacing a TCM would require programming to marry the engine to the gear box.

Well, it came from a 07 G35. It wasn't AWD either (they tried to give me one from an X model) I verified what I knew (it had the same part number as my original, but different production dates (maybe that's it?).

My mind is screaming programming, but it seems as though if it came from another vehicle with the same powertrain, should it not already have programming? Or it may have lost programming because of no battery and or sitting for so long....