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Chevrolet Silverado / GMC Sierra. Manual - part 2700
2. Ignition OFF, test for less than 1.0 ohm between the affected control circuit terminal listed
and ground.
Vertical lumbar terminal A
Horizontal lumbar terminal C
If greater than the specified range, test the control circuit for a short to voltage or an
open/high resistance. If circuit tests normal, replace the MSM.
3. Ignition OFF, test for less than 1.0 ohm between the affected control circuit terminal listed
and ground.
Vertical lumbar terminal B
Horizontal lumbar terminal D
If greater than the specified range, test the control circuit for a short to voltage or an
open/high resistance. If circuit tests normal, replace the MSM.
4. Connect a test lamp between affected control circuit terminals listed.
Vertical lumbar terminal A to terminal B
Horizontal lumbarterminal C to terminal D
5. Command the affected function in both directions with a scan tool. The test lamp should
turn ON when commanding the affected function in both states.
If the test lamp remains OFF during either of the commands, test for a short to ground
on either control circuit. If the circuits test normal, replace the MSM.
6. If all circuits test normal, test or replace the lumbar support.
Component Testing
Seat Adjuster Switch Test
1. Ignition OFF, disconnect the harness connector at the seat adjuster switch.
2. Test for infinite resistance between each control terminal and the B+ terminal with the
switch in the open position.
If less than the specified value, replace the seat adjuster switch.
3. Test for less than 1 ohm between each control terminal and the B+ terminal with the switch
in the closed position.
If greater than the specified range, replace the seat adjuster switch.
4. Test for less than 1 ohm between each control terminal and the ground terminal with the
switch in the open position.
If greater than the specified range, replace the seat adjuster switch.
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Power Seats - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
Repair Procedures
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Power Seat Switch Replacement
Lumbar Switch Replacement
Front Seat Adjuster Replacement (Power)
Front Seat Lumbar Support Replacement
Front Seat Recliner Actuator Motor Replacement
Control Module References for MSM replacement, setup, and programming
REPAIR INSTRUCTIONS
FRONT SEAT ADJUSTER SWITCH KNOB REPLACEMENT
Fig. 7: View Of Front Seat Adjuster Switch Knob
Courtesy of GENERAL MOTORS CORP.
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Power Seats - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
POWER SEAT SWITCH REPLACEMENT
Fig. 8: View Of Front Seat Adjuster Switch & Components
Courtesy of GENERAL MOTORS CORP.
Callout
Component Name
1
Front Seat Adjuster Switch Knob
Tip: Pull outward from seat to remove. If too tight, a flat-bladed tool may be
used to help disengage the knob from the switch.
Callout
Component Name
1
Front Seat Adjuster Outer Finish Cover
Refer to Front Seat Cushion Outer Trim Panel Replacement (Manual) or
Front Seat Cushion Outer Trim Panel Replacement (Power) .
2
Front Seat Recliner Switch Knob
Tip: Pull off to remove.
3
Front Seat Adjuster Switch Knob
Tip: Pull off to remove.
4
Front Seat Adjuster and Recliner Switch
Tip: Use a small flat bladed tool to disengage the switch from the outer finish
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Power Seats - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
DRIVER SEAT ADJUSTER MEMORY SWITCH REPLACEMENT (CREW CAB)
Fig. 9: Driver Seat Adjuster Memory Switch (Crew Cab)
Courtesy of GENERAL MOTORS CORP.
cover.
Callout
Component Name
1
Front Side Door Trim Panel
Refer to Front Side Door Trim Panel Replacement (YE9) or Front Side
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Power Seats - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
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