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.

 

[cr0ut0n]

You ever make any progress on this?

 

[dps01]

You ever make any progress on this?

Working on it.
Cleaned driver seat control module connections

Cleaned / reseated all connections on the memory control module.

Still need to find / clean ground on B pillar.

Also have replacement seat heater elements to install when I replace the bottom seat cover. When the seat is out, I will trace out all the wiring attached to the seat for abnormalities.

It’s intermittent, so the jury is still out.
Rained a fair bit earlier this week and today the seat heater did not cycle on its own, but I am not ready to claim success.

 

[dps01]

not ready to claim success

Success is sometimes elusive…
Have had soaking rains and the random seat heater operation saga continues.

Will do additional checks when seat is removed for leather replacement. For now may just unplug the heater harness.

 

[03yukonxldenali]

I have same problem with my 03 Yukon xl Denali. It’s at the shop today getting new heating elements. Mechanic is leaning towards it being a malfunctioning seat control module. That being said, I’ll post later when I have more information to see if this solves the problem. I will proceed to clean the grounds and check wiring next. Maybe the two of us can tackle this problem together

 

[dps01]

Mechanic is leaning towards it being a malfunctioning seat control module.

Will be interesting to see what they tell you….

Good luck… and welcome to the forum.

 

[03yukonxldenali]

Will be interesting to see what they tell you….

Good luck… and welcome to the forum.

Thanks! So unfortunately this did not solve my problem. I replaced the driver door control module and that seemed for be a small bandaid as it does continue to cycle but not as aggressively and quickly with longer gaps in between. That being said, I’m not sure where to continue from here

 

[Big Mama]

Did you find the ground on the B pillar?

 

[dps01]

unfortunately this did not solve my problem. I replaced the driver door control module and that seemed for be a small bandaid as it does continue to cycle but not as aggressively and quickly with longer gaps in between.

In my case, have not found the definitive answer either. Anecdotally, the heater cycling stops sooner if the heaters are turned off (or attempted) with the driver door open.

Will recheck ground points again as frequency was initially diminished following first cleaning.