04 ram 1500 5.7 QC I ended up needed a new pcm a while back and when I got it hooked up I had some codes and issues come up that I didn't have previously. At first it was Incorrect 3rd Gear Ratio and also for 4th gear. Along with a speed sensor code. I dont know if its in a limp mode or what but it only had 1st and 2nd manual and drive wouldn't work over about 30 mph and over that it would seem like it slipped into neutral. So then after reading up on stuff over the last couple weeks I pulled it into the garage and dropped the tranny pan and removed the filters. The fluid was quite dirty but I thought I read that I was only supposed to get about 5 or 6 quarts of fluid when dropping the pan. But when I went to pour it into empty containers I up I two 5 quart jugs and then half of a quart jug. So i only had about 6 quarts to put back in and when I did that and drove it again the codes for 3rd and 4th gear we no longer there but it now has a code for Incorrect 1st gear ratio. I didn't end up replacing the filters because I didn't have them at the time but I know I need to change them this week. But does anyone have any experience with these issues? I feel like I've gotten closer since the codes changed. I've tried to check the wiring everywhere but don't see any shorts or bad wiring. I changed my ignition switch and speed sensor in the rear diff. Next I was gonna change the input and output sensors in the trans. But if that doesnt work then I am just thinking about getting a new tranny and if I do that will I need to do a relearn of some sort or can I just install the tranny and go?

 

New or replacement trans requires a "quick learn" to reset the CVI, otherwise you run the risk of damaging the trans.

 

What about when replacing the pcm? I ordered it from flagship one and they claim their products are all plug play. Do I just need a relearn for that as well?

 

Yes, because it will not have the current CVI values of your trans. This requires dealer level scanner to perform.

 

If you don't have 3rd or 4th gears. I would drop the transmission pan and look inside the pan for any debris, like screw heads. Then with a flash light look on the passenger on the valve body and see if the side plate holding actuators is bend. If it is bend, there is a repair kit with the plate and new screws.

 

I dropped the pan and changed the filters and I didn't happen took for that cuz I didn't know but I will look at that tomorrow. Since doing the filters it wont roll when I put it in gear and let up off the brake, I have to give it some gas and then it will jerk pretty hard. I can also put it in drive and it's like it pulsate in and out of gear, both with and without brake depressed.

Could a bad instrument cluster cause any driveability issues? I checked for codes again and now comes up with p0731 I think it was which is incorrect 1st gear ratio. Also a newer code that just came up is a code for the transmission pressure control or something like that. I put in a new battery about 3 months ago and have a digital voltage display I have plugged in and when the truck is running the guage says it's around 14.8v, is that too high or is that normal.

 

It's an RFE, not an RE.

 

Yes I know it an RFE transmission and not RE. I retired after 30 years as mopar transmission tech.