Swap out seats

[WesternMike]

when i took the bezel off of my 2104 chev lt the wires when in the holes beside the heater controls

Damn, so as you can see in the photo above there are now there.

 

I'm going to remove heated panel and radio as soon as I got on days off from work and hope I find them in place.

 

 

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[pgamboa]

Damn, so as you can see in the photo above there are now there.

 

I'm going to remove heated panel and radio as soon as I got on days off from work and hope I find them in place.

 

 

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Try to poke around a little deeper when you can. When I took out my X51R Fuse Panel, I found a pigtail harness taped back. Not sure what that was for but it's there for something.

 

 

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[Darth_Vader]

It's hit or miss on the harness, I haven't found anything that shows when you might or might not have the extra harnesses. Even if you have them they won't work without BCM programming. The question is how the BCM works with the seat heater module and if you can replicate the signals directly from the switches. I have some ideas brewing but need to experiment. Potentially you could provide a cheap solution that bypasses theodules but still gives you full control.

[pgamboa]

It's hit or miss on the harness, I haven't found anything that shows when you might or might not have the extra harnesses. Even if you have them they won't work without BCM programming. The question is how the BCM works with the seat heater module and if you can replicate the signals directly from the switches. I have some ideas brewing but need to experiment. Potentially you could provide a cheap solution that bypasses theodules but still gives you full control.

So if my passenger seat is already leather and heated, but is a manual adjust, could I get the components to make it Power adjust?

 

 

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[Darth_Vader]

Doubt it, guessing the frames are radically different.

 

Just ordered the dash switches for the heaters, trying to find a control module to test.

[pgamboa]

Doubt it, guessing the frames are radically different.

 

Just ordered the dash switches for the heaters, trying to find a control module to test.

 

I guess I can look at my driver's seat which is powered and compare.. LOL..

[Darth_Vader]

 

I guess I can look at my driver's seat which is powered and compare.. LOL..

I have a power seat in my LT guess I could compare it to my WT too, lol! I found a heater control module, should have some findings, good or bad, in a week or two. Actually excited to look into this as I was talking to another programmer today about how this is probably handled through the BCM.

[wuznme]

It would be nice if GM stopped the heated seats from being controlled by the BCM, but I still think they do.

 

Tried to do this on my old NBS truck, was PITA and never worked.

 

I had the following to work with when trying:

 

Heated seats

Harness from vehicle

Door panel switches

BCM from vehicle

 

The schematic was pretty cut and dry for this and was a no go.

 

The power piece for a seat swap should be cake.

[Darth_Vader]

Yeah, I'll be analyzing the signals being related to and from the BCM and then basically replacing it with a small cheap PLC. Based on the drawings there are a couple of ways it could be interpreting the signal or even what the signal itself is but I have enough test equipment sitting around that I should be able to design a sub $100 solution.

[tbarn]

Maybe this will help.

 

Heated and Cooled Seats:

 

Body Control Module
The body control module (BCM) monitors the heated cooled seat switches through LIN bus message inputs and determines the heated cooled seat operating modes and temperature levels. Each heated cooled seat is capable of operating in 3 modes with 3 temperature levels. The BCM controls the operating mode of the driver and passenger seats through separate pulse width modulation (PWM) signal circuits. Each mode and temperature level is commanded by a different Duty Cycle. The PWM signal circuits are referenced from battery voltage by the blower assemblies and pulsed low by the BCM.

Seat Blower Assembly Power and Ground
Battery positive voltage is supplied at all times to the seat blower assemblies through a 30 A fuse that is located in the I/P fuse block. This voltage is to supply power to the TEDs, the blower motors, and the seat heater elements. The heated and cooled seat system will operate only with the ignition in the ON position. Each seat blower assembly is grounded through the ground circuit and ground connection.

Seat Blower Assembly
Each heated/cool seat has 2 blower assemblies, one located under the seat cushion and one located in the seat back. Each blower assembly contains a thermo-electric device (TED) and a blower motor. The TED is mounted downstream of the blower motor. Each TED consists of a circuit of positive and negative connections sandwiched between 2 ceramic plates. Each ceramic plate is equipped with copper fins for cool exchange. The air flowing past these fins is directed as conditioned air into the seat cushion and seat back or directed into the cabin as waste air.

Cooled Seat Operation and Blower Motors
As mentioned above in the seat blower assembly description, each seat blower assembly is packaged with a TED, blower motor, and it also contains logic that will allow for the blower to operate only when the ignition is in the ON position and only during cooled seat operation. When a cooled seat switch is pressed, the seat blower assembly applies a pre-determined voltage to the TED and blower motor. Then based on the feedback from a internal seat temperature sensor, the blower assembly controls the applied voltage to the TEDs and blower motors in order to maintain the desired seat temperature.

With cooled seat operation, the speed of the blower motor is not related directly to the High, Med, or Low input from the heated/cool seat switch. The speed of the blower motor is related directly to TED temperature. In order for the cooled seat system to operate to its optimum performance, it is crucial to have unrestricted air flow through the system. A dirty or restricted air filter, the blockage of an exhaust air duct, a misaligned blower assembly, or incorrect foam installation of the seat cushion or seat back will all have negative effects on the cooled seat system operation.

Modes of Operation
There are 3 modes available for the heated and cooled seat system operation; seat back and cushion heat, back only heat, and cool seat operation. When a heat or cool seat mode signal request is received, both the seat cushion and seat back blower assemblies will be activated. When the seat BACK ONLY mode button is pressed, the seat cushion blower assembly is turned off leaving the seat back blower assembly ON.

Heated Seat Operation
When the seat blower motor assembly receives a heated seat command, it applies a high side drive pulse width modulated (PWM) signals driven at the required duty cycles to generate the appropriate effective voltage to the heating elements to attain the commanded seat temperature.

This heated seat system utilizes a self-regulating heating element system, which is different from the non-regulated heating element systems with seat temperature sensors previously used on GM vehicles. In the self-regulating type of system, temperature feedback to a control module is not required for temperature regulation. The heating element material itself regulates the surface temperature based on the effective voltage applied to the heating element.

 

However if you're working on heated only:

 

Heated Seat Switches
The driver and passenger heated seats switches are located in the switch control panel. The body control module (BCM) monitors each switch activation to determine which seat is activated and at what temperature level. With each press of the switch, the system will cycle through High, Medium, Low, and then back to Off again.

When a heated seat switch is pressed, a LIN bus serial data message is sent from the switch to the body control module (BCM) indicating the heated seat command. The BCM serves as the heated seat system master to determine the requested operating mode. The BCM then sends a LIN bus serial data message to the seat heating control module indicating the heated seat command. The BCM also controls the seat temperature and mode indicators, via the serial data line, used to provide the operator with feedback as to the operating status of the system.

Heated Seat Operation
When the seat heating control module receives a heated seat command, it applies a high side drive pulse width modulated (PWM) signals driven at the required duty cycles to generate the appropriate effective voltage to the heating elements to attain the commanded seat temperature.

This heated seat system utilizes a self-regulating heating element system, which is different from the non-regulated heating element systems with seat temperature sensors previously used on GM vehicles. In the self-regulating type of system, temperature feedback to a control module is not required for temperature regulation. The heating element material itself regulates the surface temperature based on the effective voltage applied to the heating element.

Load Shed Management
The electrical power management function is designed to monitor the vehicle electrical load and determine when the battery is potentially in a high discharge condition. The heated seat system is one of the vehicle loads that is subject to reduction during a battery discharge condition. For more information on load management refer to Electrical Power Management Description and Operation.

[Darth_Vader]

Awesome info Tbarn! I assumed it was using PWM for temp control, and I can replicate that easily enough if need be. The real question will be the signal being sent over the LIN network from the switches. Being that they are just switches I'm guessing they are using resistive signal like the cruise control system does. It's also reassuring knowing that the LIN system can only handle one command at a time so it should be easily decipherable.

 

If you don't mind me asking, where did you find this summary? This confirms some of my assumptions I was explaining to a fellow programmer yesterday when talking about this project.

[blownZ71]

Should be plug and play if you have the electric seats, at least for the driver. Did the WT2 come with the electric passenger? You can wire power to them and get everything to work, including the heaters, just not using the stock equipment as all of that is normally powered/controlled through the BCM. I am working on doing the same thing on a WT with manual seats and utilizing the stock push buttons for control but will be doing it all with custom wiring. Sounds like you got a hell of a deal on them!

 

Mr. Vader,

 

I am also looking to put Denali leather heated/cooled seats in my SLE regular cab with manual seats. I'd like a little more info on this wiring you talked about. I am fine with just hard wiring the seats for power and then use an aftermarket auxilary switch for the heated seats. Any chance at the cool function working as well? Do you have a rough sketch of what you did in this case?

 

Thanks

[WesternMike]

Yeah, I'll be analyzing the signals being related to and from the BCM and then basically replacing it with a small cheap PLC. Based on the drawings there are a couple of ways it could be interpreting the signal or even what the signal itself is but I have enough test equipment sitting around that I should be able to design a sub $100 solution.

Looks like the seats I'm getting are cooled as well so they have the blowers on them already. Will this be a problem you think? As in plug being different?

 

 

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[Darth_Vader]

 

Mr. Vader,

 

I am also looking to put Denali leather heated/cooled seats in my SLE regular cab with manual seats. I'd like a little more info on this wiring you talked about. I am fine with just hard wiring the seats for power and then use an aftermarket auxilary switch for the heated seats. Any chance at the cool function working as well? Do you have a rough sketch of what you did in this case?

 

Thanks

Don't have anything yet as this is a work in progress. The heated seats would be easy to do with switches and probably resistors to change levels as the factory ones us Pulse Width Modulation to create the different temperature levels. That is the part I'm trying to find a work around for along with utilizing the factory switches (with custom wiring) to control it all. Cooling should operate much on the same theory. Without getting in to the deep technical jargon about how all this operates on a factory install, there are ways to replicate and what I'll be trying to figure out is if it is easier to mimic the BCM and use the stock heated seats controller or to remove both of them and create a completely new controller.

[blownZ71]

Any body happen to know if these 14-16 seats will retrofit back into a 99-02 Silverado? Does GM keep the mounting points universal through the years? I remember seeing someone do 08 seats in the previous body style, curious if they could go this route now.