Seat heater

[pdxrealtor]

Originally Posted by [__--MUD--__]

I've always had "a guy" do all my stereo/remote start ****, so I never really got in balls deep.

There are bypass units that directly plug into the truck and can communicate w/ the bus and there are ones that get cut into the factory harness....old school way.

Doesn't sound like you have the one that will communicate w/ the bus. If so, then you can eliminate the remots start from the possibility list.

I am 'that guy' but the last few years I just haven't felt like diving in like I used to.

Yet another example of 'if you want **** done right, your gotta do it yourself'.

[pdxrealtor]

Until I can round up a tech 2 or the like.....

Does anyone know how to disconnect the heater without pulling one of the fuses or relays that control multiple things.

[[__--MUD--__]]

Seat Heater: Description and Operation
Heated Seats (Front)
HEATED SEATS DESCRIPTION AND OPERATION (FRONT)
HEATED SEAT COMPONENTS
The heated seat system consists of the following components:
- Driver and passenger heated seat switches
- Driver and passenger seat back heater elements
- Driver and passenger seat cushion heater elements
- Driver and passenger seat back temperature sensors
- Driver seat module
- Driver door module
- Passenger door module
HEATED SEAT SYSTEM OPERATION
The driver and passenger heated seats have 2 heat zone operating modules with 3 heat level modes and will operate only while the engine is running.
The heat zones are determined by which of the 2 heated seat buttons are pressed, while the heat level is determined by the number of times they are
pressed. Pressing the seat cushion button 1 time will activate the seat back and cushion heater elements in the high mode. Each time the seat cushion
button 5 pressed the seat back and cushion heat level is reduced from high to medium, low, and off. Pressing the heated seat back button 1 time will
activate only the seat back heater element in the high mode. Each time the seat back button is pressed the seat back heat level is reduced from high to
medium, low, and off. During heated seat operation the heat zone operating mode may be changed without affecting the current heat level mode.
The heated Seat switches are momentary contact switches and are inputs to the driver and passenger door modules. Battery voltage is supplied to the
switch assembly from the door module, and when a heated seat switch is pressed and released a brief switch signal voltage is supplied to the door
module. Whenever the door module receives an active heated seat switch input, the next heated seat operating mode is determined by whatever the
current mode may be. The seat heater elements are controlled by the driver seat module using inputs from the door modules through Class 2 serial
data circuit messages. The driver seat module controls the voltage supply and the ground circuits to the seat heater elements. When a heated seat
function is commanded active, the seat module will switch battery voltage to the heater element supply circuits and ground is provided through low
side drive control circuits.
During heated seat operation both the seat back and cushion heater elements are supplied battery voltage. The seat module grounds the appropriate
control circuits for back only or back and cushion heating modes, and opens or closes the active control circuits as necessary in order to maintain the
desired seat temperature. The seat module relies on inputs from thermistors located in the driver and passenger seat backs to control heated seat
temperatures. The thermistors are 2 wire sensors supplied with a 5-volt referenced signal circuit and a low reference circuit from the seat module.
Resistance through the thermistors varies with temperature causing the heated seat sensor signal circuit voltage levels to decrease as the seat back
temperatures rise. The seat modules allow heated seat operation only while the engine is running which is determined by a Class 2 serial data circuit
message from the powertrain control module.

[[__--MUD--__]]

[[__--MUD--__]]

Just yank that above plug under the seat. The door module is what powers it.

There is a tsb on the heating elements not working all the time when turned on, but I see nothing about them being on by themselfs.

There is updated firmware for the door control module for 2003-2005 that corrects the issue in that tsb. Might try getting a dealership to reprogram that module. All the diagnostics requires a tech2.

[[__--MUD--__]]

****, you have an 06. guess you already have the newer firmware.

[[__--MUD--__]]

Just sitting here thinking... this poped out at me-

The heated Seat switches are momentary contact switches and are inputs to the driver and passenger door modules.

does the physical button face seem loose? Like the spring broke behind it. If the spring broke and its not holding that button open...as you drive around it could be rattling around closing the contact- activating the system.

Here is the input to the drive door module-