2003 Heated Seat Issue (Random Cycling)

[dps01]

Posting as new thread…
Heated drivers seat in 2003 Tahoe automatically turns on and cycles through the heat settings randomly.

Occurs more often after a rain / humid conditions. Only drivers seat affected.
Have previously replaced both the bottom and back heater elements as well as the heater control on the door.

If the drivers seat elements are disconnected under the seat, the passenger seat heaters will not turn on. (Do not know if that is by design of GM or another issue).

Not sure if this could be a grounding issue or a BCM issue. Waiting on delivery of a Tech2 clone to troubleshoot further.

Have a short video but unsure of how to post it.

 

[Big Mama]

Take a look under the door sill on the driver side. I had some frayed wires there that caused goofy problems in my seat.

 

[cr0ut0n]

I have the same problem on my 2003. I also replaced the heater control and it didn't seem to help. I've heard replacing the DDM can solve it but one, they're a little pricey and two, I've heard the replacements can cause other issues with power mirrors and windows.

 

[dps01]

I have the same problem on my 2003. I also replaced the heater control and it didn't seem to help. I've heard replacing the DDM can solve it but one, they're a little pricey and two, I've heard the replacements can cause other issues with power mirrors and windows.

Thanks.

Replaced the seat heater elements previously and then the heater control switch previously. Neither solved the problem for me either.

Read on another forum to take apart the DDM and clean with electronics parts cleaner, and to check the ground point near the drivers side door (need to locate exact position).

Will also check wiring bundle under driver side door sill per recommendation of @Big Mama

 

[dps01]

Take a look under the door sill on the driver side. I had some frayed wires there that caused goofy problems in my seat.

Will definitely check that wire bundle closely.

Thanks.

 

[dps01]

Updated information

From Tech2:

Currently no DTC for the driver seat module, but the following are in History, presumably from before heating element(s) were changed..

Do not use the adjustable pedals, so not sure what that issue was as they are working normally.

The multiple logged issues seem to lend credibility to either a wiring harness, ground, or a combination of the two.

 

[Big Mama]

Thanks.

Replaced the seat heater elements previously and then the heater control switch previously. Neither solved the problem for me either.

Read on another forum to take apart the DDM and clean with electronics parts cleaner, and to check the ground point near the drivers side door (need to locate exact position).

Will also check wiring bundle under driver side door sill per recommendation of @Big Mama

The ground wire is on the B pillar near the floor.

 

[dps01]

Thanks appreciate it.
Also have downloaded the pdf posted by others with the locations of the grounding points.

 

[Big Mama]

I’m not sure if the memory control module under the seat controls the heat but if so check the wires. They get knocked around under there.

 

[dps01]

not sure if the memory control module under the seat controls the heat

One more item to add to the checklist … thanks.