There are two different listings for p1757 and p0748, so im not sure which ones apply two me. I have codes...

P1757 GOV Pressure Not Equal To Target @ 15-20 PSI The requested pressure and the actual pressure are not within a tolerance band for the Governor Control System which is used to regulate governor pressure to control shifts for 1st, 2nd, and 3rd gear. (Zero Pressure Malfunction)

P1757 (M) Governor Pressure Above 3 PSI In Gear With O MPH The Govenor Pressure greater than 3 psi when requested to be 0 psi. (4-speed auto. Trans. Only)

P0748 (M) Governer Pressure Soleniod Control/Transmission Relay Circuits An open or shorted condition detected in the governor pressure solenoid circuit or trans relay circuit in JTEC RE transmissions.

P0748 (M) Governer Pressure Soleniod Control/Transmission Relay Circuits An open or shorted condition detected in the governor pressure solenoid or relay circuits (4-speed auto. Trans. Only).

I have a 2000 Dakota club cab 4x4 with the 42re tranny, to which i just bolted up a 318. Im using a 5.9PCM from a 2000 Dakota, and the original harness with the 2 injectors wired in. It sounds like all my problems have to do with my vacuum system, no? Any input is helpful.

Thanks.

 

The 5.9s use a 46re tranny, not a 42re, it looks like the pcm is throwing the wrong voltage to the Sensor, its a sensor inside your tranny valve body, try to figure out what the correct voltage that is suppost to be sent to it and if its to high, put on a resister to lower it, see it that helps any...

due to you using the wrong pcm, its going to throw codes... if the tranny is shifting ok, then just deal with it, and just slip somone an extra 20$ to pass inspections

 

Yea thats the thing. The tranny doesnt really shift at all correctly.

 

Here is the connector pinout of my Trannsmission Solenoid.
FFF.jpg
As you can see its the same one for the 3.9 and 5.9.

I did try hooking up my 3.9 PCM and checking the CEL codes, and the p0748 was the only one to come up with it. So I wanna say that the problem is not whether the Tranny Solenoid knows if it has a 5.9 or 3.9 pcm hooked up. Because there shouldnt be a difference in voltages or anything.

Did any of you that did a 5.9 swap and still use the 42re have this problem at all?

Oh, and all of the connecter pinout locations are the same on all three plugs to the pcm for 3.9 and 5.9. (The only literal difference is injectors 7&8)

Any more ideas? thanks.

Edit:

When I hooked the 5.9 PCM the p0748 was the only CEL it was throwing. The other two went away.

 

nope.

 

Ive been reading up on it and came up with a few different things for this code(P0748).

Most people who say they get this code, say that their A/C doesn't work either, and occasionally they will get an o2 sensor code.
(Both of these are true for me)

Some suggestions are to

-Replace the TPS. Some how this can affect the trannys shifting, and throw a code?
-Replace the Speed sensor on the end of the transmission.
-Drop the pan and valve body to replace the governor pressure solenoid.

During my swap, I did change the filter and fluid in the tranny. Ive seen a post from a guy in the 3rd gen ram who did nothing more than this, and it gave him this code as well. It doesn't say whether he got it fixed or not though.

Ive also seen input that it could be something wrong with the pcm. (I doubt this is my problem since i still get the CEL with my original 3.9 pcm to the truck.)


Any tranny guys out there?

Thanks.

 

bump. user? any idea?

 

Try doing the cheapest suggestion first, i just replaced my TPS due to my truck bucking at about 50mph it will jump about 400rpm and then go back down, after i changed it it went away.

The speed sensor would be the next thing to swap out, and after that the GPS which is a common problem on our trannys,

I would recommend installing a Transgo Shiftkit and a Transgo PGS Rebuild kit, i bought both of mine from this site...

http://www.oregonperformancetransmis...ry_Code=A518SK

and the solenoid rebuild kit is here...

http://www.oregonperformancetransmis...TRG-TF-GOV-SOL

 

Do you know what comes in that GPS rebuild kit? Does it include the sensor as well as the solenoid itself? NAPA has a solenoid in stock for 126$. If it has everything i need i will definitely get that kit.

If everything goes well, I will do that rebuild kit too.

 

the rebuild kit only comes with the parts to rebuild the FACTORY solenoid, that's it. The sensor is separate. You shouldn't need to buy a new solenoid if you buy that rebuild kit.