: high trans line pressure

08-24-05, 01:29 PM
Last night I replaced the motor mount on my 96 deville and the thing still shifts like garbage. I took it to the local cad. dealer and the tech said that the reason for the rough shifting was high pressure in the trans lines. is there any suggestions.


08-24-05, 01:33 PM
Possibly loose wiring/ bad connector/corrosion at the transmission, the wiring inside the transmission (specifically to the pressure control solenoid) got disconnected, or a bad pressure control solenoid.

08-24-05, 01:56 PM
I don't think high pressure would be a bad thing...maybe it'll make it shift a little harder and quicker...I know that in my old 727 Torquflite, I'm bitter if its under a hundred and forty pounds...

08-24-05, 09:49 PM
try reseting the trans. adapts in your computer to default so it can relearn. sts96

08-25-05, 11:11 AM
How would I reset the trans

08-25-05, 01:58 PM
How would I reset the trans

Try disconnecting the battery for 60 seconds. When you hook it back up, you may see a P0603 error, which means the short term memory was reset. That should eliminate the transmission adapts as well as things like the IAC and TPS learned values. It's a cheap and easy thing to try. The cost is a few minutes time and you'll have to reset your clock and radio presets.

08-25-05, 03:29 PM
The only way I found to reset the trans, adapts was with a scan tool . A shop that has one can do it in 5 min. or less. sts96

STS 310
08-25-05, 09:19 PM
sts96, havent heard from you in a while...

08-26-05, 10:24 PM
Been busy driving one N* or another till gas went up. mileage is better on my PC. sts96

08-29-05, 08:43 AM
I had the same problem on my 94 STS shifting very hard, turned out to be a bad ECM, it was sending bogus signals to the pressure solenoid. Replaced the ECM and the problem was solved.

good luck

09-06-05, 07:22 PM
I had the Trans flashed, and beat on it over the weekend. It shifts great now. I belive that the gears just had to get ran through well. Plus the new motor mount really tightened up things too....