Chevy Trailblazer Transfer Case Shift Motor Dorman 600-903

This is the electric shift motor that mounts on the transfer case of GMT360/370 midsize SUVs: the 2002-2009 Chevy Trailblazer, GMC Envoy and their Buick, Isuzu and Oldsmobile twins. The selector switch on the dash tells the module which range you want, and this motor turns the transfer case shift shaft to get there. It is a new motor, not a reman, with a factory-style sealed connector.

Fits Chevrolet Trailblazer 2002-2009 and Trailblazer EXT 2002-2006, GMC Envoy 2002-2009, Envoy XL 2002-2006 and Envoy XUV 2004-2005, Buick Rainier 2004-2007, Isuzu Ascender 2003-2008, and Oldsmobile Bravada 2002-2004.

Typical failure symptoms: Service 4WD message, 4WD indicator blinking after a shift request, no engagement in 4HI or 4LO, or the SUV stuck in 4WD and binding in tight turns. These motors live low on the case and take road spray, so a corroded connector or seized motor is common on high-mileage trucks.

Before condemning the motor, check the connector for water and green corrosion, confirm the fuse is good, and check resistance across the motor terminals. An open or shorted winding points at the motor; a good motor with no power points at the harness, switch or transfer case control module. Match the part number on your old motor or the transfer case ID tag before ordering, since these years used more than one case and motor.

On the bench: disconnect the battery, unplug the motor connector, remove the mounting bolts and pull the motor straight off the transfer case shift shaft. Before installing the new motor, note the position of the shift shaft and make sure the socket on the new motor lines up with the shaft flats; do not force it on. Bolt it down, plug it in, reconnect the battery and cycle through 2HI, 4HI, Neutral and 4LO with the engine running to confirm every range light goes solid.