A/T issue TCU code 54

[99spyder_gs]

I own a 99 spyder GS, and just recently had a rebuilt transmission put in my car (maybe 500 miles ago). Everything was great until a week ago. I was merging onto the interstate, about 3/4 throttle, car dropped a gear just fine, but when I got to cruising speed and let off the throttle the car went to shift into OD but instead acted like it shifted into neutral. I backed all the way off the throttle and then featherd it a little and it finally shifted into OD, and then did fine. Then I got curious so I gave it enough throttle to downshift, it did, then same situation when it was time for it to shift back to overdrive. I pushed it a little more this time and bam...limp mode and CEL. I stopped, cut the car off then back on, and it will run fine till I get to the point where I need OD.

CEL code is of course P1750. I read my TCU codes and got 54 (4th gear incorrect gear ratio) and 86 (incorrect gear ratio). The TCU code guides that some of you have provided (thank you all btw) suggest, for those codes, checking the pulse generators, the end clutch, and the kick down brake.

I will be ohming my pulse generators today to see if its them. From what I've researched I know most people will say end clutch, but I would think/hope the since this trans is a fresh rebuild I could elimate that and the kick down brake. Any suggestions or feedback would be great. I've already spent too much money as it is putting another transmission in my car so im trying to center down this problem as best as possible.

 

[99spyder_gs]

Well, I ohmed my pulse generators, and if I did it right they showed around 450ohms. Which based on the guides I've seen they should be between 330-390. So I ordered some and they should be here Monday. I'll post up if this fixes the problem or not.

I'm still eliminating the possibility of it being the end clutch because when I am able to get it into OD it runs fine. So if replacing the pulse generators doesn't fix the problem, then I guess the only thing left is a bad TCU. Any input would be great guys. And even though I'm able to read codes off the TCU just fine, could it still be causing this?

 

[Grimey]

Did a shop rebuild the trans for you or did you do it yourself? If you just had the transmission rebuilt by a shop, shouldn't it still be under some sort of a warranty? You shouldn't have to be buying parts and repairing a fresh rebuild after only 500 miles.

 

[99spyder_gs]

Yeah I probably should have clarified a little. I got the trans from a place in Atlanta. It was hard to find (like everything for a 4g64 apparently), and I had to wait 2 weeks for them to find and rebuild one. The shop that installed it was the closest one to me that they required me to use so I could get the warranty. So yes there is a warranty, but the shop looked at it for about 10 mins and immediately said it was my TCU. Based solely on the fact that their OBD II scanner would not communicate with the TCU. So I took matters into my own hands and read the codes from the TCU myself (which I told them how to do btw). I called the shop back and told them what I had found and they said, "I wouldn't drive the car, and you need to call the place you got the trans from." Not driving the car was not an option because I had to go to Birimingham for something that was just short of a family emergency. Car did just fine when I could get it into OD. Even when it wouldn't go into OD, I just ran it with the OD switch off with no issues.

Anyway, the big point is, if $76 pulse generators will fix the issue, then whether I should have to pay for them or not, it will be worth not having to wait 2 weeks + without my car. And if it is the TCU, that will not be covered under the warranty. Which is why I was asking if people thought the TCU could be bad.

 

[99spyder_gs]

Well, it wasn't the pulse generators. Back to the drawing board.

 

[99spyder_gs]

Ok, it's all fixed.

It ended up being a busted seal in the end clutches. Apparently when it was rebuilt they put the seal in wrong.

The company I got the trans from is called Transmission planet. They pissed me off at first but I have to give it to them. One of their customer service guys (Brad) really helped me out and more than made up for the screw up. He bought and shipped the IPT end clutches to me, and paid to get them installed at a local tranny place.

Hope this helps some people out.