Some vehicles may exhibit inadvertent 4X4 Hi or Low shift events, 4X4 and/or Low Range indicator flashing or solid or vehicle stuck in 4L after uncommanded shift. This may be caused by the 4X4 shift motor.
Install a YL1Z-7G360-AA shift motor on vehicles built before 12/99. The YL1Z-7G360-AA shift motor with a grey contact plate cover replaces the prior design F75Z-7G360-AA motor with a blue contact plate cover. Grey cover shift motors contain improved sense plate material and shift motor terminal upgrade. For vehicles already equipped with the latest style shift motor, refer to the following Service Procedure for details.
For overall description and operation of the Electronic Shift On The Fly (ESOF) Transfer Case, refer to Section 308-07 of the appropriate model year Workshop Manual.
After the initial event the vehicle may exhibit restricted vehicle top speed without 4X4 indicators illuminated but possible MIL (Malfunction Indicator Lamp) on.
If contact plate PIDS DO NOT correspond to the set 4WD position, check for continuity/shorts/moisture/corrosion in the vehicle side of the transfer case shift motor connector (toward the GEM). Visually inspect all terminals, pins, crimps, and connectors closely. Repair any wiring conditions in the contact plate circuits as necessary.