2003 suburban transmissionnot shifting from 1-2 or 2-3

Take it to a qualified repair shop .

This code is for a Transmission range sensor. Which can cause a vehicle to shift properly or go into gear correctly. Here are the problems that could cause that to malfunction.

• Defective Transmission Range Sensor (PRNDL input)
• Defective Transmission Range Sensor (PRNDL input) wiring or connector
• Defective Valve Body
• Defective manual shift valve linkage
• Dirty transmission fluid that restricts the hydraulic passages

First we need to figure out what transmission you have. Crawl under the vehicle on the drivers side (be sure to chock your tires) and see if there is a black box on that side of the transmission. If so, then it is the 4L60E and there are many electronic parts that could be the culprit. Also while you're under there check and see if your shift linkage is hooked up, that will be on that same(drivers) side of the transmission. While your under there getting dirty, you could park the vehicle on level ground, chock the front wheels, jack up the entire rear of the vehicle and place it on jackstands. With the rear of the vehicle up in the air you could un-bolt the shift linkage and try to manually shift the transmission. If that works, you could have a broken shift linkage, or if you do have the 4L60E out may be that little black box where the shift linkage attaches to the transmission. Good luck and be careful!

1 Ck A/T fluid level & quality
2 Scan/ck for code(s)
3 With scan tool connected,road test vehicle/Ck parameters....
....time for a pro !!

If you need further help, reach me via phone at https://www.6ya.com/expert/ralph_2f0886b7d6af32ce

Kickdown cable unhooked, attaches next to accelerator petal cable.

Have you retrained the gear? From memory think goes motor running foot firmly on brake park to neutral three times, neutral to reserve three times, neutral to drive three times, keep going thru all gears Then drive car normal for ten minutes minium as you usually would.

I would have it towed to a transmission shop and checked out!

Take it out for a drive on a country road and floor it...it may be the transmission or solenoid valves are stuck this should unfreeze them also check for corrosion in the electrical plugs to transmission clean them with vinegar and apply electrical contact grease and reconnect them

with the key off shift to neutral,while holding the brake to keep it from rolling away,then start it then shift into drive--once home replace the brake switch maybe thats all you will need to do.

Good day
It sounds like the dran tube is pluged. Have you had the car undercoated lately, or have you drove over frestly paved roads, or drive alot on non pave roads? All you have to do is just free up the drain tube and it should be fine. the tube should be around the right side around the pass, door area Hope this helps

Cheers