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-   -   Transmission code P0750 (http://www.jeepgarage.org/f203/transmission-code-p0750-34515.html)

01grand 01-22-2012 03:46 PM

Transmission code P0750
 
I have been having trouble lately and the transmission is going into limp mode. I should mention, its a 01 WJ with the 545rfe. The code is P0750, shift solenoid A malfunction. Here is an exact quote from wjjeeps.com:

Note: If code P1767 (Transmission Relay Always On) is also present: Replace transmission solenoid assembly. See note provided. When transmission is in limp mode the relay that provides power to the solenoid group is switched off. This is normal and is designed to provide operation in one gear only.

Engineering department suggests to replace transmission solenoid assembly anytime these two trouble codes occur together. See applicable service manual section (21) for solenoid assembly replacement directions. IMPORTANT: When performing this repair always check torque on all valvebody accumulator cover plate screws. Proper torque specification is 70 inch pounds. If any accumulator cover plate screws are damaged or missing replace the valvebody assembly. NOTE: If any other trouble codes are present do not replace solenoid assembly. See test in the applicable Transmission Diagnostic Procedures Manual.

This only mentions if code P1767 is also present, but it is not. Anyone else seen these codes? I should mention that they came on a few weeks ago, I cleared the code, and it was fine for a while. Now this weekend it came up, I cleared it, and it came back again. Any help would be appreciated. Thanks.

cheapjeep 01-22-2012 09:42 PM

Re: Transmission code P0750
 
Aaron do you have a service manual? If not pm me your address.

Frango100 01-23-2012 04:54 AM

Re: Transmission code P0750
 
Normally with this code there is something wrong with the solenoid block. But before changing anything, have a look at the connector on the left hand side of the tranny. The connector could be loose or have dirty connector pins. Clean it out with some contact cleaner,let it dry, reconnect and try again. When the fault returns, then its probably the solenoid block itself.

01grand 01-23-2012 09:59 AM

Re: Transmission code P0750
 
Quote:

Originally Posted by Frango100 (Post 558602)
Normally with this code there is something wrong with the solenoid block. But before changing anything, have a look at the connector on the left hand side of the tranny. The connector could be losse or have dirty connector pins. Clean it out with some contact cleaner,let it dry, reconnect and try again. When the fault returns, then its probably the solenoid block itself.

Thanks for the tip Frank! I will check that out as soon as the winter crap dries up a bit around here, we are finally getting a decent amount of snow.

01grand 01-23-2012 11:42 PM

Re: Transmission code P0750
 
Ok, so while driving to work this morning the code came back. When I got to work I cleared it and before leaving to lunch I used my superchips to return the vehicle to stock. No codes since. I am starting to wonder if maybe the solenoid is on its way out and the tuning (plus maybe the way I drive with it on) is causing the problem. Seem possible? I know its only been one day I plan on running a while without the tune and see what happens.

cheapjeep 01-24-2012 12:55 AM

Re: Transmission code P0750
 
Quote:

Originally Posted by 01grand (Post 559261)
Ok, so while driving to work this morning the code came back. When I got to work I cleared it and before leaving to lunch I used my superchips to return the vehicle to stock. No codes since. I am starting to wonder if maybe the solenoid is on its way out and the tuning (plus maybe the way I drive with it on) is causing the problem. Seem possible? I know its only been one day I plan on running a while without the tune and see what happens.

I hope not leadfoot!

Frango100 01-24-2012 03:03 AM

Re: Transmission code P0750
 
Iīm not familiar with tuning, but isnīt it only changing the programming of the PCM, or does it do something with the TCM as well?
Well, only time will tell now if it has something to do with it.

01grand 01-24-2012 09:21 AM

Re: Transmission code P0750
 
I believe the tuning bumps up the line pressure and changes shift points, and I know it makes harder, quicker shifts.

Also, I keep getting P0456 lately, which is a very small vacuum leak. I tightened my gas cap again, but I'm starting to think its something else. Guess I will have to start checking vacuum lines.

cheapjeep 01-24-2012 02:17 PM

Re: Transmission code P0750
 
Try a new cap first Aaron.

Frango100 01-24-2012 02:21 PM

Re: Transmission code P0750
 
And if the cap doesn't help, the rubber hoses above the rear axle are known to get dry and crack.

01grand 01-27-2012 05:12 PM

Re: Transmission code P0750
 
Update: No codes have come back all week. I cleared the codes Monday morning and took the tuning off then. No codes, so on Wednesday I decided to try the mileage tune to see if that makes a difference for the 3 hour trip I have this weekend. No codes since then, and hopefully none over the weekend, I will report back on Monday.

This leaves me wondering, do I have a weak solenoid that fails under the added pressure of the performance tuning? If all goes well this weekend I will try the tuning again next week, I think that would confirm the problem if it comes back.

I did not get a chance to check the wire connector like you suggested Frank, but I'm thinking now that if the connector were loose it wouldn't make a difference if the tuning was on or not.

Frango100 01-27-2012 05:46 PM

Re: Transmission code P0750
 
I donīt know what the tuning exactly does Aaron, but indeed you would expect the same problem with or without the tuning if it was related to the connector.
Or if the solenoid would draw more current due to switching a higher line pressure, it could still have to do with a resistance problem in the connector.
If the problem comes back, that would be the first thing i would check, and it would only cost some time and contact cleaner.


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