GM-GMC: Power and heated seat function stopped working, yukon denali xl, yukon xl

Question
Yesterday my automatice seat adjustment and heated seat stopped working on the driver side.  Seat adjustment works on passenger but not the heated seat function.  Any idea what is wrong

Answer
There is a bulletin for symptoms similar to the ones you are describing.  I will attach it below.  Unfortunately you require a scanner to test alot of the switch and module communications.  You could always try disconnecting your battery for 48hrs and see if the modules reset.
hope this helps




#03-08-50-003: Seat Heater and/or Memory Power Seat Inoperative (Replace Memory Seat Control Module) - (Jan 21, 2003)


Subject: Seat Heater and/or Memory Power Seat Inoperative (Replace Memory Seat Control Module)


Models: 2003 Cadillac Escalade, Escalade ESV, Escalade EXT

2003 Chevrolet Avalanche, Silverado, Suburban, Tahoe

2003 GMC Sierra, Yukon, Yukon XL, Yukon Denali, Yukon Denali XL

2003 HUMMER H2




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Condition
Some customers may comment that the seat heater and/or memory seat functions are inoperative.

Cause
A logic lockup of the memory seat control module may cause this condition.

Correction
Important: This repair is not to be performed on vehicles without memory/heated seats. If the vehicle does not have memory/heated seats but has an inoperative power seat, use published Service Information to diagnose the concern.

If the seat is currently inoperable, perform the following diagnostic steps to determine if replacement of the memory seat control module is the correct repair:

Connect a Tech 2® to the vehicle and monitor the parameters in the sensor data list for the driver seat module as you try to move the seat. Are the displayed data parameters changing, or does the Tech 2® display no communication as the seat switch is moved to various positions? If the data parameters do not change, the memory seat control module may be inoperative due to a logic lockup.
Remove the SEAT circuit breaker in the instrument panel relay block located under the left side of the instrument panel next to the parking brake. This circuit breaker also supplies power to the passenger seat.
Verify that the circuit breaker is not open. If it is not open, wait 30 seconds and then reinstall the circuit breaker.
Try to move the seat again.
If the seat moves or the data parameters displayed on the Tech 2® change when the seat switch is activated, replace the memory seat control module. Use the Memory Seat Control Module Replacement procedure in SI.
If the memory seat is still inoperative, use normal Service Manual diagnostics to determine the cause of this condition.