NP246 Transfer Case Encoder Shift Motor, Chevy Silverado

This is the electric shift motor, also called the encoder motor, that bolts to the back of the transfer case on GM full-size trucks and SUVs with push-button four wheel drive. It replaces Dorman 600-910 and GM 12384980, and also crosses to 19125571, 19125640, 88962314, 420-00138 and Mopar 5170543AA. Fitment covers 2003-2007 Chevrolet Silverado 1500/2500 and Avalanche, 2003-2007 Tahoe and Suburban 1500/2500, 2003-2007 GMC Sierra 1500/2500 and Yukon/Yukon XL, 2003-2007 Cadillac Escalade, ESV and EXT, plus Ram 1500 2006-2010 and Ram 2500 2007. The unit is new, not remanufactured, and comes with the factory-style connector and a sealed housing.

The symptom that sends people here is a dash that will not change ranges. You press 4HI or 4LO, the light blinks and goes back to 2HI, or all four lights flash and stay flashing. Sometimes the truck sticks in 4LO and will not come out. The encoder motor is doing two jobs at once - the motor turns the sector shaft inside the case, and the encoder ring inside the same housing reports shaft position back to the transfer case control module. When the encoder contacts wear or corrode, the module loses position, throws a C0327 encoder circuit code, and refuses to shift. A motor that has seized will also blow the transfer case fuse.

Replacement is a drop-the-skid-plate, three-bolt job on most of these trucks. Disconnect the battery, unplug the connector, pull the three 13mm bolts holding the motor to the case, and slide the old unit off the sector shaft. Before the new motor goes on, do the two things the failures come from: check that your harness connector pin count matches the connector on this motor, and do not rotate the new motor to line it up. The motor comes indexed from the factory - rotate the sector shaft on the transfer case instead so the flats line up, then seat the motor and torque the bolts evenly. Do not apply power to the motor on the bench. Reconnect the battery and cycle through 2HI, 4HI and 4LO with the engine running and the trans in neutral to let the module relearn position.