2001 LS- Only 1st and Reverse
#1
2001 LS- Only 1st and Reverse
Hi, one night car works fine, next morning it's only got 1st gear, and reverse. No slipping, fluid level is correct, no hard driving the night before. My original thought was that it was in limp mode, and it was in 2nd gear, but it seems to reach higher rpms at too low of a speed and starts out quick with no laziness like a 2nd gear start would have. So I originally think it's STUCK in 1st gear, but I drove it a little more today and it will shift out of 1st if you're rolling down a hill with no throttle. Then if you give it some throttle, it just revs up, until the car slows down to roughly 30 or so, and 1st gear will grab again. There's no slipping, no anything. I scanned codes, and since the list is long and full of 'B' codes, and that many of them are connection related, I would think it needs a new BCM anyway. Here is the list...P1571, U1040, U1016, B0041, B1000, B2618, B2655, B3106, B3127, B3128, B3132, B3133, B3137, B3138
Any ideas? A shop I have no faith in told them it's a bad transmission, but it just doesn't seem right to me.
Any ideas? A shop I have no faith in told them it's a bad transmission, but it just doesn't seem right to me.
#2
CF Senior Member
You have a lot of codes there! Everything from ECU malfunction to communication loss, to light dimming failures, to lock signal failures. How is the battery? I had a similar problem years ago with my Saturn. The AC-Delco battery was leaking acid onto the negative side post thereby causing extensive corrosion on the ground connection. I would look to see if you have a stable voltage and grounds. check the battery, then even look into the possibility of an ECU failure. I would break open a Service Manual and follow the troubleshooting flow charts.
#3
It's been sitting since that fateful morning, so I'm assuming most of those body codes are due to that. These are the codes I got before I cleared it and drove it. Of course I realized how late for work I was, and forgot to write down what came back. I'm pretty sure it was P1571 and U1040 that came back for sure, and B0041 and B1000. I will recheck though.
Mainly I wanted to get the transmission issue out on the board for input.
Mainly I wanted to get the transmission issue out on the board for input.
#4
CF Senior Member
The transmission is electronically controlled. So, if the ECU has problems, it won't tell the transmission when and if to shift.
Here is a link to an outside site that has a good explanation of the GM Turbo Hydramatic 4T65-E
Facts on the GM Turbo Hydramatic 4T65-E
Here is a link to an outside site that has a good explanation of the GM Turbo Hydramatic 4T65-E
Facts on the GM Turbo Hydramatic 4T65-E
Last edited by Frank3; November 13th, 2014 at 2:39 PM.
#5
Long overdue update...Finally got back over to look at the car. Checked cables, charged battery, checked body grounds I could find, cleared codes and took it for a drive with the scanner on. According to the scanner, it has 1st and second, and will also shift into 3rd and 4th. 1st seems to work fine, 1/2 and 2/3 solenoids (if I remember right) are on, then one of them shuts off for the shift to 2nd. I don't notice a real shift into second, but the scanner says it shifted. Then over about 30 or 35, it shifts into 3rd, which is not there. If I go fast enough in 2nd,and let off and coast, it'll shift to 3rd, and then 4th (on the scanner), and 4th is also not there. As for codes, I can't get the U1016 to clear, but it's only listed as history. And when I was messing with the scanner's other modes, I did get a U1040 to pop up a as a current code. I am assuming the answer is an internal failure in the transmission. Any thoughts on the U1040 code?
#6
Link Broken
The transmission is electronically controlled. So, if the ECU has problems, it won't tell the transmission when and if to shift.
Here is a link to an outside site that has a good explanation of the GM Turbo Hydramatic 4T65-E
Facts on the GM Turbo Hydramatic 4T65-E
Here is a link to an outside site that has a good explanation of the GM Turbo Hydramatic 4T65-E
Facts on the GM Turbo Hydramatic 4T65-E
I am job interviewing and I need my car to work. Is there anything we can do without getting the transmission rebuilt? Thanks!
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