ACDelco GM Original Equipment 88962315 Transfer Case Range Select Position Sensor

Fits as factory - 2004 Avalanche 1500

Great price for the OEM part. Aftermarket encoder rings were almost twice the price. The 4WD has been out for 12 years (It mostly sat up, didn't drive it much) finally decided to find out what was wrong, and after doing some research and borrowing a proper scan tool, confirmed the issue was the encoder ring. Dropped the encoder motor, took it apart, swapped out the ring, bolted it back on, turned the ignition on and the 2WD light was now on, all modes worked, and the "Service 4WD" message was gone.

Waaayy cheaper than replacing the whole encoder motor. Most of the time it is only this sensing ring that is gone bad. At a fraction of the cost of a Tcase motor you can replace this part. Took me 45 minutes start to finish. All error codes are gone, the Tcase shifts smoothly, no more grinding from partial shifts position. Get it.

2005 Tahoe Z71. This resolved my issues with random issues with my 4 wheel drive. The first symptom occurred while driving down the road in 2-wheel drive and it slipped into neutral. I pulled over and shifted through all of the gears with no change. I was fairly certain that a transmission doesn't act like that when it goes unless it fell out of the vehicle. That helped me to narrow it down to the transfer case. I noticed the light next to the 2-wheel button was off so I pushed the Auto button and could feel the transfer case engage. I put it in drive and away I went. Periodically I would try to switch it back to 2-wheel and it would always slip back into neutral after a mile or so. I kept it in Auto for a few months and then started to notice that it would randomly engage the 4-wheel drive while on the pavement, yikes! Not wanting to destroy my front wheel drive, I learned that I could set it to 2-wheel and then crawl under the vehicle and completely remove the transfer shifting unit, which this device is inside (BTW, no need to remove the driveline to get it out but it takes a bit of twisting and turning to get it out, it's very tight). You lose the ability to change the transfer case setting unless you manually adjust it with a wrench underneath but it now won't be shifted unintentionally. These transfer cases are basically the same as they were 20 years ago but they have just replaced the stick on the floor with a motor and some electronics to do the manual work and coincidently, those electronics are the culprit for the majority of issues on these vehicles. Once you have the shifting unit (I don't know what it is called) off the transfer case, it is fairly easy to replace the sensor. This sensor tells the computer what gear it is in and then the computer turns the motor as needed to select the correct gear. When this sensor starts to burn out, it sends incorrect signals to the computer, which then starts to move the motor around to find the correct position and that leads to the random transfer case behavior. Your symptoms may be different. From reading online forums, it appears that this sensor is the problem 60% of the time and the switch on your dash accounts for about another 35% of transfer case problems; your mechanic doesn't want you to know that. I took apart the shifting unit on my dining table, swapped out the sensor, and put it all back together while watching the game. I don't remember anything difficult or tedious about the process. I re-installed it about one year ago and no issues since.

The only part that seems to fail in the automatic transfer case encoder motor, way cheaper than the whole unit, but be sure to only buy the AC Delco part, it’s the only one that works