P0751 code

my 2003 impala just gave me its first code yesterday. I think the computer put it in limp mode because the tranny wont really shift and also i noticed that the cruise control didnt work after this. I checked the code and the only one in there was the P0751 shift solinoid A CKT performance or stuck open. where is this solinoid and can it be taken out without going into the tranny? can it be cleaned or should i just get a new one. any suggestions would be great. thanks.

my 2003 impala just gave me its first code yesterday. I think the computer put it in limp mode because the tranny wont really shift and also i noticed that the cruise control didnt work after this. I checked the code and the only one in there was the P0751 shift solinoid A CKT performance or stuck open. where is this solinoid and can it be taken out without going into the tranny? can it be cleaned or should i just get a new one. any suggestions would be great. thanks.
First welcome to a/f. The shift solenoids are in the auxiliary valve body in the side of the trans, this is not really a dyer type job, accesss if difficult, axle has to come out, should be on a lift also. But this should be scanned with a trans capable scanner to command and confirm solenoid operation for a proper diagnosis.

I agree with Shep. You are having a problem with the 1-2 shift solenoid. DTC P0751 will disable shift adapts, force maximum line pressure, and inhibit 3-2 downshifts when the vehicle speed is greater than 30 mph. Therefore, the reason for the erratic/bad shifting. It is about a $450 - $600 job at a typical reputable tranny shop.

I would give the transmission case connector a good once over unhook it by squeezing the sides and make sure all the pins are the same height < tranny side and make sure none of the spades on the harness side have backed out. there has been issues with the connector being not seated correctly also.

thanks, i am going to spend the day today changing the filter and fluid even though the fluid still looks brand new at 70K. and also look at all the connections, i am just not sure which one is solinoid A. all the normal shop manuals dont go into that much detail when it comes to trannys. should be a fun 4th. its starting to shift now between 2nd and 3rd but not into 1st and i dont think it goes into 4th. but the shift from 2 to 3 is hard.

thanks, i am going to spend the day today changing the filter and fluid even though the fluid still looks brand new at 70K. and also look at all the connections, i am just not sure which one is solinoid A. all the normal shop manuals dont go into that much detail when it comes to trannys. should be a fun 4th. its starting to shift now between 2nd and 3rd but not into 1st and i dont think it goes into 4th. but the shift from 2 to 3 is hard.

Shop manuals are worthless unless it is a ATSG GM Techtran Manual.

On a 4T65E tranny solenoid A is the 1-2 shift solenoid. It is located under the side cover assembly on the driver's side of the tranny, left hand side of the valve body along with the PCS and TCC-PWM solenoids. It is not really a simple DIY job but can be done DIY but involves a lot more than simply removing a cover.

As Troy (Tranny Tech) suggested check the 20 way umbilical connector located on the driver's side at the top of the side cover. Remove it and then re-install, then see what it does.

well i tried unplugging the harness and it looked clean inside with no damage that i could see, plugged it back in and still the same. i just checked my warrenty and i still have 20k left on it. i couldnt remeber what warrenty package it had bought and it says solinoids are covered so against everything i normally would do i will call tomorrow to make an appointment with the shop, god i hate that. at least now i can start drinking and enjoy the holliday :) thanks all for the help!!

About a month ago I noticed that my transmission fluid was brown. It is not think at all, and it does not smell burnt. It was weird to me because a month b4 that it was fine. The only thing that I can think about is when one day I noticed the dip stick tube was loose. I don't know why, but it was. Maybe one of the mechanics that had been working on my car somehow touched it and it got loose. I when to a transmission shop, but the guy refuses to even look at it. He says I need a new one or rebuilt... One even told me that my car would not got over 50 mph, but today I proved him wrong. He said if I tried to go over 50 mph, my car would start "screaming" but nope! HOWEVERRR, when I got off the expressway (was doing about 60 mph on the expressway), the check engine light came on. When I reached my destination, I took out my Car Code Reader... it had 2 codes "P0751 and P0751 P". I know its suppose to be the shift solenoid (P0751) but does anyone know what the second one with the P means?

P0751 and P0751 P is the A solenoid stuck off. Means that there is debris or crap in the fluid which is holding the solenoid off. Not necessarily an electrical problem but the code was generated, as the ECM detected the failure and thus turned the light on and generated the code. Will run you about 800.00 at the dealer as with my '05 it was in the tranny. Clean fluid may clean it out. I have an excerpt from a bulletin which I will share with you.
Possible causes

- Low transmission fluid level
- Dirty transmission fluid
- Faulty shift solenoid 'A' valve
- Shift solenoid 'A' valve harness or connectors
- Shift solenoid 'A' valve circuit is open or shorted
When the a transmission solenoid is stuck off, in most cases the problem is not the electrical part of the solenoid; the problem is foreign material obstructing the mechanical function of the solenoid or the flow of the fluid through the transmission valve body. If the transmission fluid is very dirty, it is recommend changing the transmission fluid and if possible removing the transmission pan for further diagnosis. Excessive debris or metal particles on the transmission pan could be an indication that there is a transmission mechanical failure and that the transmission will need to be rebuilt or replaced.

The P0751 code is detected when the gear required by the ECM does not match the actual gear when vehicle is driven.

Shift solenoid valve 'A' is turned ON or OFF by the Transmission Control Module (TCM) in response to signals sent from the park/neutral position (PNP) switch, vehicle speed and Engine Control Module (ECM) (throttle opening). Gears will then be shifted to the optimum position.