How do you operate heated seats - 2000 Ford Expedition

Check for battery power on the orange wire pin D and ground (black wire) pin C- Brown wire pin B should be ignition hot on connector C1 on the Driver Climate Control Seat Module located under the driver seat. If you have power and ground, you may need to use a scan tool to see if there are any codes stored in the module. If the scan tool is unable to communicate with this module, it could either be a bad module or a network problem. If you are missing either battery, ignition hot, or ground- then repair as needed

Heated Seat System Operation
The driver and passenger heated seats have 2 heat zone operating modes 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 is 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.

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

Do you know what B - body DTC -diagnostic trouble code are ?
DTC B2425 Driver Seat Heater Circuit
DTC B2435 Driver Seat Back Heater Sensor Circuit
DTC B3941 Front Seat Heaters Circuit

Heated Seat Always On
Step
Action
Yes
No
Schematic Reference: Driver Seat Schematics and Passenger Seat Schematics
Connector End View Reference: Power Seat Connector End Views
1
Did you perform the Diagnostic System Check - Vehicle?
Go to Step 2
Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2
Operate the heated seat system.
Does the system operate normally?
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
Go to Step 3
3
Install a scan tool.
Display the Heated Seat Status parameter in the driver seat module Input/Output data list.
Start the engine.
Does the scan tool display the Heated Seat Status parameter as Off?
Go to Step 6
Go to Step 4
4
Display the Heated Seat Mode parameter in the door module Inputs data list.
Does the scan tool display the Heated Seat Mode parameter as OFF?
Go to Step 6
Go to Step 5
5
Turn OFF the ignition.
Disconnect the heated seat switch connector to the door module.
Start the engine.
Does the scan tool display the Heated Seat Mode parameter as OFF?
Go to Step 7
Go to Step 8
6
Replace the driver seat module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
Is the repair complete?
Go to Step 9
--
7
Replace the heated seat switch. Refer to Front Seat Heater Switch Replacement .
Is the repair complete?
Go to Step 9
--
8
Replace the door module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
Is the repair complete?
Go to Step 9
--
9
Operate the system in order to verify the repair.
Did you correct the condition?
System OK
Go to Step 3


your best bet , have a qualified repair shop diagnose the problem

Not a fuse issue , more then likely a burnt heating element in the seat , happens all the time .
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

The control module have a Battery voltage supply , the module supply's voltage to the seat heating elements .
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.

Your best bet , take it to a qualified repair shop.

Looking at a wiring diagram for the passenger seat an checking wiring colors mite help you figure it out . But then again maybe not . Electronic's involved here , Right door module .
Heated Seat Components
The heated seats consist of the following components:
• Left heated seat switch
• Right heated seat switch
• Memory seat module
• Left door module
• Right door module
• Left seat cushion heating element
• Left seat back heating element
• Left seat cushion temperature sensor
• Right seat cushion heating element
• Right seat back heating element
• Right seat cushion temperature sensor
Modes of Operation
The heated seat module (MSM) controls heated seat operation for both the driver and passenger seats. There are 2 modes of operation available for heated seats; both the seat cushion and seat back heat, or seat back only heat. When a heated seat temperature signal request is received, the MSM will activate both the seat cushion and seat back heating elements. When the heated seat BACK ONLY mode button is pressed once the MSM will deactivate the seat cushion heating element and leave the seat back heating element ON.

Heated Seat Switch/LED Indicators and System Operation
The left and right heated seats are controlled by separate heated seat switches located in the door panels. Ground is supplied to the heated seat switches through the switch low reference circuits from their respective door modules. The door modules also control the heated seat switch heat mode and temperature indicators. The memory seat module (MSM) controls the heated seat operation for both, the left and right heated seats.
The following describes the sequence of operation and how the MSM responds to each of the switch inputs.
• High Temperature--When the heated seat switch is pressed once, ground is applied through the switch contacts and the switch signal circuit to the door module indicating the high heat request. In response to this signal, the door module applies a low current voltage through the 3 temperature indicator control circuits illuminating all 3 LEDs indicating the high temperature mode. The module then sends a message via the GMLAN serial data line to the MSM indicating the heated seat request. The MSM then applies battery voltage through the heating element supply voltage circuit to the seat cushion and seat back heating elements. At the same time, it supplies a ground through the element low reference circuits to the seat heating elements.
• Medium Temperature--When the switch is pressed a second time, the MSM sets the temperature level to medium heat. The door module removes the voltage from the high temperature indicator leaving 2 LEDs illuminated indicating the medium temperature mode.
• Low Temperature--When the switch is pressed a third time, the MSM sets the temperature level to low heat. The door module removes the voltage from the medium temperature indicator leaving 1 LED illuminated indicating the low temperature mode.
• System OFF State--When the switch is pressed a fourth time, the MSM removes the battery voltage and grounds from the heating elements. The door module removes the voltage from the low temperature indicator, indicating the system OFF state.
• Back Only Mode-When the heated seat is ON and the BACK ONLY mode button is pressed, ground is applied through the switch contacts and the heated seat back only mode signal circuit to the door module. In response to this signal, the door module sends a GMLAN message to the MSM indicating the back only mode request. The MSM then opens the ground path to the seat cushion heater element, leaving the seat back heater active. The door module turns OFF the seat cushion/back mode indicator, then applies a low current voltage through the heated seat back only mode indicator control circuit illuminating the back only mode indicator.

Know how to test an what test is the key to finding the problem .Not guessing . The connector you found may or may not have anything to do with it . What color are the wires ? I have factory service repair manual . Does it have memory seats ?
The Memory Seat System consists of the following components:
• Memory seat module (MSM)
• Seat horizontal motor
• Seat front vertical motor
• Seat rear vertical motor
• Seat recline motor
• Lumbar horizontal motor
• Seat horizontal position sensor
• Seat front vertical position sensor
• Seat rear vertical position sensor
• Seat recline position sensor
• Lumbar horizontal positional sensor
• Seat adjuster switch
• Seat lumbar switch
• Memory seat switch
• PWR SEATS Circuit Breaker 30 A
• MEMORY RPA Fuse 7.5 A

Electronic's ! drivers Power seat module , driver door module . Do you know anything about automotive electronic's ?

The heated seat module (MSM) controls heated seat operation for both the driver and passenger seats. There are 2 modes of operation available for heated seats; both the seat cushion and seat back heat, or seat back only heat. When a heated seat temperature signal request is received, the MSM will activate both the seat cushion and seat back heating elements. When the heated seat BACK ONLY mode button is pressed once the MSM will deactivate the seat cushion heating element and leave the seat back heating element ON.
The adjustable pedal system is controlled by the memory seat module (MSM).
your best bet , have a qualified repair shop check it out ! Could have DTC'S - diagnostic trouble codes in door module , BCM etc...

Heated Seats
This system allows the electrical heating of the front seats on passenger demand.
The components of the system are:

• the seat heating elements located in the seat cushion and backrest.
• the heated seat control switch, located on the seat side trim panel.
• temperature sensors located in the seat cushion heating elements.
• heated seat relay.

Do both front seat heaters not work ? Do you know how to test electrical circuits with voltmeter ?
PINPOINT TEST J: THE HEATED SEAT IS INOPERATIVE Test Step Result / Action to Take J1 CHECK HEATED SEAT SWITCH OPERATION

• Key in ON position.
• Press the heated seat switch on the driver and passenger seats.
• Are both heated seat switch indicators illuminated?

Yes
If both indicators illuminate, Go To Pinpoint Test K . If only one indicator illuminates, GO to J5 .

No
GO to J2 . J2 CHECK THE HEATED SEAT RELAY CIRCUITS

• Key in OFF position.
• Disconnect: Heated Seat Relay C3250 (located under the driver seat).
• Key in ON position.
• Measure the voltage at heated seat relay C3250-86, circuit 1003 (GY/YE), harness side and ground; and between C3250-30, circuit 566 (DG), harness and ground.
  
• Are the voltages greater than 10 volts?

Yes
GO to J3 .

No
REPAIR inoperative 1003 (GY/YE) or 566 (DG) circuit. TEST the system for normal operation. J3 CHECK HEATED SEAT RELAY GROUND CIRCUIT

• Key in OFF position.
• Measure the resistance between heated seat relay C3250-85, circuit 57 (BK), harness side and ground.
  
• Is the resistance less than 5 ohms?

Yes
GO to J4 .

No
REPAIR circuit 57 (BK). TEST the system for normal operation. J4 CHECK THE HEATED SEAT RELAY

• Install a fused jumper lead between heated seat relay 3250-30, circuit 566 (DG), harness side and heated seat relay C3250-87, circuit 1064 (YE/LB), harness side.
  
• Do both heated seat indicators illuminate when pressed?

Yes
INSTALL a new heated seat relay. TEST the system for normal operation.

No
REPAIR circuit 1064 (YE/LB) to switches. TEST the system for normal operation. J5 CHECK INOPERATIVE HEATED SEAT SWITCH INPUT

• Key in OFF position.
• Disconnect: Heated Seat Switch C320 (Driver) or C321 (Passenger) for the inoperative heated seat.
• Key in ON position.
• Measure the voltage between heated seat switch C320-2 (driver) or C321-2 (passenger), circuit 1064 (YE/LB), harness side and ground .
  
• Is the voltage greater than 10 volts?

Yes
GO to J6 .

No
REPAIR circuit 1064 (YE/LB). TEST system for normal operation. J6 CHECK CIRCUIT 57 (BK) FOR AN OPEN

• Measure the resistance between heated seat switch C320-4 (driver) or C321-4 (passenger), circuit 57 (BK), harness side and ground.
  
• Is the resistance less than 5 ohms?

Yes
INSTALL a new heated seat switch. TEST the system for normal operation.

No
REPAIR circuit 57 (BK). TEST the system for normal operation It's not that simple , being a fuse . It's probably the relay or the heating element .
PINPOINT TEST K: SEAT DOES NOT HEAT BUT THE HEATED SEAT INDICATOR ILLUMINATES WHEN PRESSED ? Does it ?
Your best bet would be to take to a qualified repair shop .
Do

The following diagnosis might be helpful if the vehicle exhibits the symptom s described in this PI. Condition Concern Driver and passenger heated seats inoperative or shut off in 30 seconds. There will be DTCs B2435, B2440, B3606 and or B1825 set in the Drivers Seat Module. The adjustable pedal position sensor, seat recliner position sensor and both heat seat thermistors share the same 5 volt reference internal to the Drivers Seat Module. A fault in any of these components circuits can make the heated seats inoperative or shut off in 30 seconds, as well as, the seat recliner and/or adjustment pedals may move in short increments when operated. A fault in heated seats, adjustable pedal or seat recliner will affect BOTH heated seats. Note Even if the vehicle is not equipped with adjustable pedals DTC B3606 still may set.Recommendation/Instructions To help isolate the area of concern use the Tech 2 and go to Sensor Data in the Drivers Seat Module. Monitor the following parameters for being out of range Recline Position Normal range .39V 4.58V Pedal Position if equipped Normal range .39V 4.58V Psgr. Seat Heat Sensor- Normal range 1V-4V Drvr. Seat Heat Sensor Normal range 1V 4V If a parameter is found to be out of range inspect circuits for any opens, shorts to ground, or voltage. If none found replace the suspect component Please be aware of the following common areas of concern The adjustable pedal position sensor internally shorted pulling the 5 volt reference low. Disconnect the adjustable pedal position sensor and see if the heated seats start working correctly, if so replace.Note Important The APP accelerator Pedal Position sensor is NOT the adjustable pedal position sensor. Make sure the correct sensor, adjustable pedal position sensor, is disconnected.The seat recliner position sensor internally shorted pulling the 5 volt reference low. Disconnect the recliner position sensor and see if heated seats start working correctly, if so replace.An open in either heated seat thermistor circuits signal or low reference The most common is the passenger thermistor where it passes through seat connector C305 pin L or K or C399 pins R or G A chaff to ground on either heated seat thermistor signal circuits. The most common is circuit 5475 black red or dark blue shorted to ground in the passenger seat near the buckle.Note Important The heated seat thermistors act differently to OPENS and SHORTS than the adjustable pedal position sensor and seat recliner position sensor. The adjustable pedals and seat recliner sensors can be disconnected for testing of the heated seats. Where as the heated seat thermistor circuit must be working correctly before EITHER heated seat will operate. Disconnecting one thermistor, which may have a concern will not allow the opposite heated seat to work correctly, BOTH side must be operational before EITHER heated seat will perate.Clearing DTCs If DTCs will not clear when using the Tech 2 after a repair has been made, try operating the device in which the repair was made. Example, if a repair was made to the passenger heated seat thermistor circuit, the DTCs may not clear unless the passenger heated seat is operated.Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed GM bulletins are intended for use by professional technicians, NOT a do it urselfer. They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

The purpose of this bulletin is to provide the technician with the following service nformation Heated Seats Switch Operation Heated Seats Switch Diagnostics Heated Seats Switch Customer Information Switch Operation The engine must be running for the heated seat feature to work. The heated seats will shut off automatically when the ignition is turned off.Two buttons, located on the door, are used to control the heated seat. Press the orizontal (RH) button to heat the entire seat, back and cushion. Press the vertical (LH) button to heat ONLY the seat back.The three light bars are an indicator of the level of heat selected for either the entire seat (horizontal button) or ONLY the seat back (vertical button) To heat both the seat back and seat cushion at the same time, press the horizontal (RH) button with the heated seat symbol one time. All 3 light bars will glow indicating the HIGH temperature etting.The horizontal (RH) button does NOT have an ON FF indicator light.Press the button a second time, 2 light bars will glow indicating the MEDIUM temperature setting for the entire seat.Press the button a third time, 1 light bar will glow indicating the LOW temperature setting for the entire seat.Press the button a fourth time to turn the entire heated seat OFF.To heat ONLY the seat back, press the vertical (LH) button one time. An ON FF indicator light over the heated seat back symbol will glow to designate that ONLY the seat back is being heated.All 3 light bars over the horizontal (RH) button will glow indicating the HIGH temperature setting for ONLY the seat back.Press the button a second time, 2 light bars will glow indicating the MEDIUM temperature setting for ONLY the seat back.Press the button a third time, 1 light bar will glow indicating the LOW temperature setting for ONLY the seat back.Press the button a fourth time to turn the heated seat back OFF.Switch Diagnostics mportant: In order to eliminate unnecessary part replacement and comeback repairs, it is essential that the appropriate diagnostic tables and aids found in the applicable manuals are followed.Verify the condition prior to making any repairs. Refer to Seats and Seat Controls in the applicable Owners Manual or this bulletin for proper heated seat switch operation information.If an improperly operating front heated seat condition exists, refer to the Diagnostic Information and Procedures in the Seats sub-section of the applicable Service Manual in order to diagnose the system accurately.When measuring the resistance of the seat heater elements, ensure the values are within the updated range of 1.5-5.5 ohms. Refer to DTC B2425 or B2430-Clearing the DTC in the Diagnostic Information and Procedures in the Seats sub-section of the applicable Service Manual.Customer Information Some heated seat components from the above listed vehicles have been returned to the Warranty Parts Center (WPC) for heat function not operating properly. Analyses of these parts show 'no out of specification condition' or No Trouble Found (NTF)Provide customers with the knowledge that if bumped, either one of the heated seat switches can be activated/deactivated accidentally.Ensure customers have a thorough understanding of how the heated seat switches function.GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

Would you say it stays on about 30 seconds and does the passenger side do the same thing? If possible retrieving the codes will narrow down the search for a correct solution.If the passenger side is ok we may be able to eliminate the passenger side as bring part of the problem.Please advise so will know which way to go with your solution.


Condition/Concern: Driver and passenger heated seats inoperative or shut off in 30 seconds. There will be DTCs B2435, B2440, B3606 and/or B1825 set in the Drivers Seat Module. The adjustable pedal position sensor, seat recliner position sensor and both heat seat thermistors share the same 5 volt reference internal to the Drivers Seat Module. A fault in any of these components/circuits can make the heated seats inoperative or shut off in 30 seconds, as well as, the seat recliner and/or adjustment pedals may move in short increments when operated. A fault in heated seats, adjustable pedal or seat recliner will affect BOTH heated seats.
Note:: Even if the vehicle is not equipped with adjustable pedals DTC B3606 still may set.


To help isolate the area of concern use the Tech 2 or a comparable scanner and go to "Sensor Data" in the Drivers Seat Module. Monitor the following parameters for being out of range:
Recline Position- Normal range .39V-4.58V
Pedal Position (if equipped) - Normal range .39V-4.58V
Psgr. Seat Heat Sensor- Normal range 1V-4V
Drvr. Seat Heat Sensor- Normal range 1V-4V
If a parameter is found to be out of range inspect circuits for any opens, shorts to ground, or voltage. If none found replace the suspect component.

Please be aware of the following common areas of concern:

1. The adjustable pedal position sensor internally shorted pulling the 5 volt reference low. Disconnect the adjustable pedal position sensor and see if the heated seats start working correctly, if so replace. Note Important:: The APP (Accelerator Pedal Position) sensor is NOT the adjustable pedal position sensor. Make sure the correct sensor, adjustable pedal position sensor, is disconnected.
   
2. The seat recliner position sensor internally shorted pulling the 5 volt reference low. Disconnect the recliner position sensor and see if heated seats start working correctly, if so replace.
3. An open in either heated seat thermistor circuits (signal or low reference). The most common is the passenger thermistor where it passes through seat connector C305 pin "L" or "K" or C399 pins "R" or "G".
4. A chaff to ground on either heated seat thermistor signal circuits. The most common is circuit 5475 black/red or dark blue shorted to ground in the passenger seat near the buckle. Note Important:: The heated seat thermistors act differently to "OPENS and SHORTS" than the adjustable pedal position sensor and seat recliner position sensor. The adjustable pedals and seat recliner sensors can be disconnected for testing of the heated seats. Where as the heated seat thermistor circuit must be working correctly before EITHER heated seat will operate. Disconnecting one thermistor, which may have a concern will not allow the opposite heated seat to work correctly, BOTH side must be operational before EITHER heated seat will operate.
   

Clearing DTCs
If DTCs will not clear when using the Tech 2 or comaparable scanner after a repair has been made, try operating the device in which the repair was made. Example, if a repair was made to the passenger heated seat thermistor circuit, the DTCs may not clear unless the passenger heated seat is operated.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

Here is a heated seat TSB for cars built prior to 12/14/07

TSB 09-4-8
03/09/09
INOPERATIVE HEATED SEAT(S) - BUILT
BEFORE 12/14/2007

FORD:
2005-2007 Five Hundred, Freestyle
2008 Taurus X, Taurus

MERCURY:
2005-2007 Montego
2008 Sable

ISSUE
Some 2005-2007 Freestyle, Five Hundred, Montego and 2008 Taurus, Sable and Taurus X vehicles built before 12/14/2007 may exhibit an inoperative heated seat(s). This concern may be caused by an intermittent open element in the heated seat mat.

ACTION
Follow the Service Procedure steps to correct the condition.

SERVICE PROCEDURE
The heated seat system is controlled by the heated seat module located underneath the front passenger seat cushion. The heated seat switches are part of the heating ventilation air conditioning (HVAC) module but the heated seat system operates independently from the climate control system. The heated seat module regulates seat temperature by monitoring resistance of a thermistor type thermostat located in the cushion heater mat. The heated seat module is designed to remain on, heating the seat and maintaining temperature until switched off. For vehicles built before 5/1/2006, the module will time-out and switch off after 10 minutes.

1. Refer to Workshop Manual (WSM), Section 501-10 for pin point test on inoperative heated seat(s).
a. When testing the heater mats resistance and circuits for an intermittent open, technicians should sit in the seat while testing the circuit resistance, move the seat in multiple seating positions and apply pressure to several areas of the heated seat mat to ensure the mat element is not open intermittently.

2. Refer to WSM 501-10 for heated seat element replacement when an open electrical circuit has been identified.

Parts Block
WARRANTY STATUS: Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
IMPORTANT : Warranty coverage limits/policies are not altered by a TSB. Warranty coverage limits are determined by the identified causal part.

OPERATION DESCRIPTION TIME
MT090408 Use SLTS Operations If Actual
Available Or Labor Time
Performed As Actual Time

DEALER CODING
CONDITION
BASIC PART NO. CODE
14D696 28

I hope this helps to solve it.

I will post it in 2 different posts because its too long DB

HEATED SEAT SYSTEM
Individually controlled driver and passenger side electrically heated front seats are available factoryinstalled optional equipment on this model, when it is also equipped with the power seat option. The heated seat system allows both the driver and the front seat passenger the option to select one of two seat heating ranges, Low or High, or to turn the individual seat heaters OFF using the heated seat switches located in the center lower bezel near the bottom of the instrument panel center stack. The heated seat switch circuit operates on ignition switched battery current supplied through a fuse in the junction block, only when the ignition switch is in the ON position.

The heated seat system consists of the following components

• Heated seat elements
• Heated seat sensors
• Heated seat module (or memory heated seat module)
• Heated seat switches.

The heated seat system also relies upon resources shared with other electronic modules in the vehicle over the Programmable Communications Interface (PCI) data bus network. The PCI data bus network allows the sharing of sensor information. This helps to reduce wire harness complexity, internal controller hardware, and component sensor current loads. At the same time, this system provides increased reliability enhanced diagnostics, and allows the addition of many new feature capabilities. For diagnosis of these electronic modules or of the PCI data bus network, the use of a DRB scan tool and the proper Diagnostic Procedures are recommended.

The electronic modules that may affect heated seat system operation are as follows:

• Body Control Module (BCM) - Refer to Body Control Module in Electronic Control Modules for more information.
• Heated Seat Module (HSM) - Refer to Heated Seat Module in Electronic Control Modules for more information.
• Memory Heated Seat Module (MHSM) - If the vehicle is equipped with the Memory System, refer to Memory Seat Module in Electronic Control Modules for more information.

Refer to Power Seats Premium I/III in the Contents of Wiring Diagrams for complete circuit diagrams. Following are general descriptions of the major components in the heated seat system.

The heated seat system will only operate when the ignition switch is in the ON position, and the surface temperature at the front seat heating element sensors is below the designed temperature set points of the system. The heated seat system will not operate in ambient temperatures greater than about 41 °C (105 °F) . The front seat heating elements and sensors are hard wired to the Heated Seat Module (HSM) or the Memory Heated Seat Module (MHSM).

The heated seat switches are hard wired to the Body Control Module (BCM). The BCM monitors the heated seat switch inputs, then sends heated seat switch status messages to the HSM or MHSM over the Programmable Communications Interface (PCI) data bus. The HSM or MHSM contains the control logic for the heated seat system. The HSM or MHSM responds to the heated seat switch status messages, ignition switch status messages, and the front seat heating element sensor inputs by controlling the output to the front seat heating elements through integral solid-state relays.

When a seat heater is turned ON, the sensor located on the seat cushion electric heater element provides the HSM or MHSM with an input indicating the surface temperature of the seat cushion. If the surface temperature input is below the temperature set point for the selected Low or High heated seat switch position, the HSM or MHSM energizes the integral solid-state relay, which supplies battery current to the heating elements in the seat cushion and back. When the sensor input indicates the correct temperature set point has been achieved, the HSM or MHSM de-energizes the solid-state relay. The HSM or MHSM will continue to cycle the solid-state relay as needed to maintain the temperature set point.

The HSM or MHSM and the seat heater elements operate on non-switched battery current supplied through the power seat circuit breaker in the junction block. However, the HSM or MHSM will automatically turn OFF the heating elements if it detects an open or short in the sensor circuit, a short or open in the heating element circuit causing an excessive current draw, or when the ignition switch is turned to the OFF position.

See the owner's manual in the vehicle glove box for more information on the features, use and operation of the heated seat system.

I WILL POST THE REST