Question about 2007 GMC Yukon XL Denali

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Seat warmer's not heating properly

I have misplaced my owner's manual:
I thought I remember my seat warmer's going on automatically like the heater does in cold weather when I use auto start, but this is no longer happening. Also, the seat warmer's seem to not get warm on level 3, but if you go down to level 1 it heats up dramatically then you need to go to level 3 to maintain. I thought I remember level 3 as the highest and you just put it on that to get the seats very warm. Am I incorrect? Thanks.

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The most probable answer to that is the valve connecting the heater to the seat has a hole or is not connected properly. Just to be safe check with a car mechanic

Posted on Dec 29, 2008


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Hi, I have a 2005 Chrysler 300C and the seat warmer won't turn off. I have to unplug the battery when I turn it off, as it runs down. I can't get to the link posted. Help!

Wendy, the heated seat relay or switch could be bad, a good tech. may have to run diagnostics on it and locate fault and give estimate for repair. In the meantime instead of unhooking battery, look in your manual and find the heated seat fuse/relay and unplug it, verify seats are not heating up and then leave fuse/relay out until you can have it checked out or try a new relay and see if that corrects your problem. I will post links to your fuse boxes, I believe one in trunk and one under hood. Check the attached links,instruction and guides, Good luck
"I hope this helped you out, if so let me know by pressing the helpful button. Check out some of my other posts if you need more tips and info."
Flashing seat warmer switch

Jul 06, 2016 | 2005 Chrysler 300

1 Answer


Perhaps it is not the fuse, but you can try looking in the owners manual, If you have lost the owners manual, try going to Chrysler parts or 'MOPAR" online and looking at the manual there... good luck.

Dec 20, 2014 | 2004 Chrysler Sebring Convertible

1 Answer

My left seat heater dont work

check to see if you have power to seat switch if so check power going out of seat switch. if so check connection to heat coil in seat if connected an have power replace seat warmer.

Dec 05, 2014 | Seat Cars & Trucks

1 Answer

The passenger seat warmer doesn't work and the fan won't blow on the feet. Sounds like a fuse, maybe? What can I do?

when two or more electrical gadgets die together, there is generally a common cause. the fuse is a protection device, not something which goes bad on its own. the seat is basically a toaster that you sit on, but running on 12 volts instead of house current. all kinds of things can and do go bad with constant heating and cooling. the fan for the heating and A/C is much more necessary than the seat. so get in your owners manual, find the fuse panel and the fuse and replace it. use the fan, but not the seat. it will cost more than you want to spend to fix it, pretend you are Amish and have to live with an
unheated seat.

Feb 24, 2011 | 2005 Dodge Grand Caravan

1 Answer

Where do i check gear boox fluid and top up . drivers heated seat stoped working

Manual transmission fluid level is checked through a fill plug on the side of the transmission. THe fluid should be level with the bottom of the hole. Automatic transmission fluid is checked via a dipstick under the hood. Your owners manual should have detailed instructions for checking both.
For the seat heater, check the fuses, then the electrical connectors and wire connections under the seat.

Dec 30, 2009 | 2002 Jeep Grand Cherokee

1 Answer

Heated Seat Quit Working

hi you should check the fuses first.look in your ovners manual or on the fuse panel lid and under hood fuse block/s for the proper fues and location.

Feb 02, 2009 | 2002 Chevrolet Monte Carlo

1 Answer

2002 Grand Cherokee Heated Seats don't work

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

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.


Jan 31, 2009 | 2002 Jeep Grand Cherokee

1 Answer

Chevy Silverado Seat Heater not working

The most likely cause is the seat heater elements, they either have excessive resistance or are open - id recommended replacing both driver side element - upper and lower

Jan 17, 2009 | 2004 Chevrolet Silverado 2500HD

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