Ok guys, I've got a 2002 jimmy 4X4 with a transmission problem. Motor runs great. If I put it in drive it starts out in high gear? I can downshift and upshift manually and it will shift. It's kinda jerky shifting manually when it shifts but it will shft. From what I've read it could be internal or possibly just a selenoid. I know there are two selenoids, 1-2 and 3-4. If just one of these selenoids went bad could it cause this? I don't think they would have both went bad at the same time. Oh this transmission only has about 75,000 miles on it. Thanks

 

Anyone?????

 

I'm experiencing the same problem when the transmission warms up.

 

Ok so I'm getting code P1875. How could that cause my not shifting problems. I know it's electical now because the problem is coming and going. Sometimes the truck shifts by itself through all gears normally, sometimes starts out in 3rd or 4th it's hard to tell which.

 

Sounds like the transmission is in Limp-in mode. 3rd gear with a manual 2nd. check for blown fuses.
P1875 is:
Description 4WD Low Switch Circuit Electrical (4L60-E Transmission)
Cause DTC P0122, P0123, P0502, P0503, P0740, P0742, P0751, P0752, P0756, P0758, P1810, P1860 and P1870 not set, engine speed over 450 rpm for 5 seconds, Fuel Cutoff not active, VSS input over engine vacuum at 0-105 kPa, gear range is D4, shift solenoid performance counters at zero, TFT input from 68-266°F, then Condition 1: 4WD Low switch in 4WD low, transfer case not in 4WD low, TCC slip speed from -3000 to -50 RPM, and VCM detected the speed ratio was 0.8-1.2 (speed ratio is rpm divided by the output speed) Condition 2: 4WD Low switch not in 4WD low, transfer case in 4WD low, TCC commanded on, TCC slip speed was 100 to 3000 RPM, and the VCM detected that the speed ratio was 2.5-2.9 for 10 seconds.

Here's something I found on P1875...

"Welcome to JustAnswer, my name is XXXXX XXXXX I'm here to help get your problem resolved. Yes this most likely means the transmission control module has failed, you can buy a used one from www.car-parts.com to save money. Go to the Powertrain Control Module Black connector pin 23 Gray/Black wire and probe the wire with a voltmeter. With the truck in Two wheel drive, there should be 12 volts there. If the truck is in 4 wheel drive then it should show 0 volts. If it shows 0 volts, then disconnect the transfer case Control Module or remove the wire from the PCM and see if the transmission shifts normally. If it shifts normally, then verify the Gray/Black wire is not shorted to ground. If the wire is OK, then replace the TCCM."

Hope this helps