Bought truck from a friend that said it needed to warm up a few minutes before it shifted right. Test drive took 1/2 mile not shifting before shifting perfectly. I would let the truck warm up about 5 min and it shifted fine, for 4 months, 95% of the time. Sometimes, after just shutting it off, I had to drive around a parking lot until it shifted right or stopped and restart. I replaced the two pressure sensors, replaced the accumulator spring (was broken) with upgrade, and the bar( broken) on the front band adjuster. No luck. ONE TIME while driving around the block I shut it off, started it and immediately dropped into drive and it shifted perfectly through all gears. None of the  dash guages, speedo or tach was working. When I had to stop, I shut it off and started and all the guages worked again but no shift. I can pull into 1st at 10 mph and it downshifts but no upshift. Bought a scantool and only codes I get are P0230 and P1693. I'm thinking electrical because it has always shifted great even with the dash inop. Keyswitch, ECM, speed sensor, ????? Any help will be greatly appreciated.

I would talk to @Dynamic he's the site transmission guru. From what I know the 1st, 2nd and 3rd gears are all hydraulicly controlled. The only thing I can think of is governor pressure sensor or governor pressure solenoid is goofy. But that is random guess with my limited knowledge. @Dynamic would know the answer.

It definitely sounds like you have an electrical issue.

 

Is it starting in 1st, and then not upshifting, or is it starting in 3rd?

Thanks Dynamic, It starts in 3rd, I guess, won't upshift, but will downshift into ???? if I pull shifter into 1st @ 10mph. If I mash on the pedal it feels like it's back in the higher gear.Like I said, before it might do this twice in one week or it might not happen for months. I would usually turn it off and restart (sometimes 2 or 3 times) then it would act perfectly. Then it quit shifting. I've checked and cleaned fuses,  and switched out relay I will check to see if it has 12 volts at the plug going into the tranny in the morn. Past that I'm stumped  and will try anything. I appreciate any expert advice you might have.  I just can;t get over the one time I shut it off, started it right back up and pulled it into drive and it shifted perfectly all the way to overdrive But all the guages, speedo and tach were not working. Drove it about a mile, had to stop, restarted, all the guages worked but stuck in 3rd. Thanks again.

Any idea if someone raised line pressure? I have had an issue on my 97 but it would not trip a fault code. Someone had a dtt box installed probably 10 years ago at least. As soon as I pulled it.....little to no issues.

Thanks jlbayes for the thought and time to think about this. I don;t know about the line pressure or how to go about checking it.I also have no idea what a dtt box is or where to look to see if one is on there. If you could give me some direction I will try it. I;ll research it.

 

I have learned so much from this site from the members posting actual thought out intelligent info. The pics, wiring diagrams and overall concern in solving the problem has my respect. Thanks again.

There are test ports around the transmission. @Mopar1973Man might have the test procedure on here. To be honest I have not looked yet to verify.

 

DTT box, mine was mounted right on the pcm. Which is on the right side of the bulk head. Near the receiver drier and air filter.

might double check that you have the right wiring harness on the valvebody for your year truck.  I have an 01 with the flat transducer and it got replaced with an older round golden one once.  It had your symptoms.  It had to come up to operating temps before it would shift correctly. 

Edited April 11, 20187 yr by JCutter

Thanks JCutter. I  replaced the gov pressure sensor and transducer with same style parts that was in it. I just plugged them in but didn't inspect the harness. I will check the harness down to the trans plug and make sure there is power there then go inside and recheck the wiring and sensor connections . Hope I didn't get bad sensors. Will  update progress if any. Thanks again.

What sensors did you put in.  Did you have a gold round one with a oval plug or a black flat plug with black transducer?  That's what I was leaning toward.  I have an 01 that has the flat black plug and it was replaced at one point with the gold round/oval plug.  There is a pressure and temp difference that it reads....from what I was told.  Yours being a 98 should of had the gold oval one. 

Edited April 11, 20187 yr by JCutter

Thanks JCutter. It had the gold round one. I replaced the gov pressure sensor with the Borg Warner. Everything plugged back the same except the 180 degree twist( which I found out later) of the harness for the Borg . I replaced the accumulator spring while I was in there. It was broken.I adjusted the bands on the inside and figured i had it. When I tried to adjust the bands on the outside the adjuster went too far in the case so I went back research mode and found the video of the front band adjustment bar or band broken. Plus I started doubting myself on the Borg being snapped in all the way and the harness twisted 180. Pulled the pan. The harness was plugged in properly but the front band bar was not there. More research. Pulled the valve body down, not out, and found all the pieces on top on the valve body. Replaced it with the upgrade. made sure everything went back together right, adjusted the front band, and put pan on. Still no shift out of second. The bar and acc spring did not have shiny breaks so they must have been broken when the truck was shifting properly. Since I did all that work it has only shifted perfectly one time when I shut it off, started it and immediately put it in drive and took off. Shifted through all the gears and od. Even downshifted out of od and back in again like it should.But none of the gauges, tach or speedo worked Shut off after 1 1/2 miles, started it up, gauges all worked but no shift. It's something electrical or a bad connection or ??? Thanks for the reply.