Seats - Power GMC Suburban I

DESCRIPTION & OPERATION

A 6-way power seat is used on driver's seat (all models) and passenger seat (some models). System consists of 3 reversible motors attached to a seat drive rail. Each motor contains a self-resetting circuit breaker. Power seat switch is located on left side of driver's seat, or on right side of passenger's seat. Drive cables connect motor to gearnuts, which turn jack screws and adjusters at each side of seat.

HORIZONTAL OPERATION OF SEAT NOT SMOOTH, APPARENT HARD

OPERATION

1. Check improper lubrication of adjuster shoes and channels. Lubricate carriages and seat adjuster slides with lithium base grease.
2. Check adjuster horizontal actuator gear for being over tightened to rack gear. Tighten mounting screws or replace transmission assembly, if necessary.

HORIZONTAL CHUCK OR LOOSENESS

Check improperly adjusted horizontal actuator to rack gear. Check seat adjuster carriages that may be out of alignment or worn. Correct by inspecting transmission assembly, and replace if necessary.

ONE ADJUSTER WILL NOT OPERATE HORIZONTALLY

1. Check horizontal drive cable disconnection or damage. See appropriate test under «TESTING»(/gmc/suburban/i-1992-1999/remont/seats/#seats-power) for correction.
2. Check inoperative horizontal actuator. Check drive cable and adjuster motor assembly. Replace horizontal actuator if damaged.

ONE ADJUSTER WILL NOT OPERATE VERTICALLY

Check for disconnected or damaged vertical drive cable. Replace vertical drive cable if damaged. Also check for inoperative vertical gearnut. Replace vertical gearnut if damaged.

BOTH ADJUSTERS WILL NOT OPERATE HORIZONTALLY &/OR VERTICALLY

Check for damaged, broken or inoperable solenoid plunger, shaft, dog, dog spring, gear or drive gear. Replace damaged, broken or inoperable solenoid.

VERTICAL CHUCK OR LOOSENESS

Check for excessive clearance at vertical gearnut tension spring. Correct by grinding down top of vertical gearnut shoulder nut to 0.015-3.64" (0.40-1.19 mm) maximum.

PRELIMINARY TESTING

Check power accessory circuit breaker. If motors operate but seat does not move, check for obstruction in seat drive rail or check for broken drive gear. If seat tilts forward and/or rearward but does not move up or down, replace switch.

POWER SEAT(S) DOES NOT OPERATE IN ANY DIRECTION

1. Disconnect switch connector. Check for voltage at Orange wire. If voltage is present, go to next step. If voltage is not present, repair open circuit in Orange wire between fuse panel and switch connector.
2. Check continuity of Black wire between switch connector and ground. If continuity is not present, repair open in Black wire between switch connector and ground.

POWER SEAT(S) DOES NOT RAISE OR LOWER AT FRONT ONLY

1. Connect jumper wire between Yellow and Black wires at switch connector. Momentarily connect jumper wire between Light Blue and Orange wires at switch connector. Note seat movement.
2. Connect jumper wire between Light Blue and Black wires at switch connector. Momentarily connect jumper wire between Yellow and Orange wires at switch connector. Note seat movement. If seat moved, replace switch. If seat did not move, go to next step.
3. Connect Yellow wire to Light Blue wire at power seat switch assembly connector. Remove connector from front tilt motor. Check continuity of Yellow and Light Blue wires between switch connector and front tilt motor connector. If continuity is present, replace front tilt motor. If continuity is not present, repair open in Yellow or Light Blue wire between switch connector and front tilt motor.

POWER SEAT(S) DOES NOT RAISE OR LOWER AT REAR ONLY

1. Connect jumper wire between Dark Green and Black wires at switch connector. Momentarily connect jumper wire between Dark Blue and Orange wires at switch connector. Note seat movement. If motor moves, replace power seat switch assembly. If motor does not move, go to next step.
2. Connect jumper wire between Dark Blue and Black wires at switch connector. Momentarily connect jumper wire between Dark Green and Orange wires at switch connector. Note seat movement. If motor moves, replace power seat switch assembly. If motor does not move go to next step.
3. Connect Dark Green wire to Dark Blue wire at power seat switch assembly connector. Remove connector from rear tilt motor. Check continuity of Dark Green and Dark Blue wires between switch connector and rear tilt motor connector. If continuity is present, replace rear tilt motor. If continuity is not present, repair open in Dark Green or Dark Blue wire between switch connector and rear tilt motor.

POWER SEAT(S) DOES NOT MOVE FORWARD/REARWARD

1. Connect jumper wire between Dark Blue and Black wires at switch connector. Momentarily connect jumper wire between Tan and Orange wires at switch connector. Note seat movement. If motor moves, replace power seat switch assembly. If motor does not move, go to next step.
2. Connect jumper wire between Tan and Black wires at switch connector. Momentarily connect jumper wire between Dark Blue and Orange wires at switch connector. Note seat movement. If motor moves, replace power seat switch assembly. If motor does not move, go to next step.
3. Connect Tan wire to Dark Blue wire at power seat switch assembly connector. Remove connector from forward/rearward motor. Check continuity of Tan and Dark Blue wires between switch connector and forward/backward motor connector. If continuity is present, replace forward/backward motor. If continuity is not present, repair open in Tan or Dark Blue wires between switch connector and forward/backward motor.

Removal & Installation (Power Seat)

Remove screws from front and rear of seat trim cover. Remove seat retaining bolts. Remove seat from vehicle.

Power Seat Wiring Diagram (Without Lumbar Support). Scheme 1

Power Seat Wiring Diagram (With Lumbar Support). Scheme 2

See also:
• TESTING