Heated Seats

you cant fit heated seats if not fitted with them from the factory , they are not simply switched on and off by a switch , they are controled variably by the CEM and the CEM on yours wont have the software and it cant be added ..

Would the CEM not come with the software loaded regardless of whether heated seats were fitted or not? Martin

Hi, Also, are not heated seats a part of the "Winter Pack" which is an option? Ergo, how do you install an option if the facility is not available? Des. . . ;)

You can get retro-fit heating pads, Landrover (?) make them I think.... You could fasten the live & earth wires into a power source (ie - the back of the cigarette lighter). No promises you won't burn the fuse / wiring / whole car though! Chris

OK, so I've purchased heated seats and the control panel/buttons for 2001 S80. Do I have to get the dealer to program the computer to make them work?

Assuming you are going to install the seats anyway you have nothing to lose by trying although I dont doubt what Clan is saying . The heater wiring is already there as you have found , the yellow/grey wire to the seat plug is for control and its standard in the V70 P2 harness . The switches are connected to the CCM and this uses canbus to communicate with the CEM so no extra wiring needed for this but if the heating option is not programmed into the CEM then nothing is going to happen . If you have some electrical knowledge you could remove the underseat electronic controllers and make up your own hard wired relay controllers and make use of the existing heating elements and thermistors , the Y/Gr wire could be disconnected from the CEM and used for the new controller , there is also a suitable + and - supply to the seats so no extra power wiring needed . The pitfalls of this are that if the car catches fire the insurers would probably see the modification and refuse to pay out and it seems there have been plenty of fires caused by faulty heated seats so would recommend you dont go down this route . I wonder how this affects aftermarket heated seat kits , I notice they never mention any risks or insurance implications in their advertising .

The volvo seat elements are controlled in a different way to how you think , they are rapidly switched on and off avout 100 times a second , ( Pulse Width Modulation ) heat is controlled by holding them on a bit longer with each cycle . If you connect them direct to 12 volts you are likely to burn them out within seconds ..