Auto transmission stuck on low gear

[mnm816]

2003 Jeep liberty 4WD after replacing 3 speed sensors it is now stuck on a low gear threw code P0731 it also has codes P0500 which is a speed sensor code but it could be from before replacing sensors and P0161 (sensor heater) need help figuring out why is the transmission stuck? Any tips will be greatly appreciated. Have a good day !

 

[KJowner]

Low gears 1&2 are limp home mode with the transmission in non electronic control mode, however if its only selecting 1 then you may have an issue with the transmission.
If it can't see the speed or the speed is implausible the TCM drops into limp mode. As the fault happened after you changed the speed sensors I would look at them and the wiring and connectors first and check the gearbox oil level, only use ATF4+ anything else will damage the gearbox.
A normal code reader can't see all gearbox codes, just the engine PCM mimic codes. You need to get a garage with a high end scanner to read the TCM fault codes.

p0500 is a faulty rear speed probe for the ABS and speedo, the one in the back axle. Maybe a historical code if you haven't cleared them recently?

If P0731 is an active code then that's what is holding the gear shift out, it's seeing a speed fault in the gearbox.