3v Lithium battery is located at the bottom of the NCU in the module with the fan (see picture).
Proceed as follows
1. Gently push the dual fan/battery module backwards (by pressing on the pressure point) to
release the module from its front interlock (snap-in hooks).2. Tilt the dual fan/battery module forwards at an angle and pull out the plastic guide from
the Control Unit cutout.
3. Remove the battery by first removing the plug connector and then taking out the battery.
4. Connect the cable plug connector of the new battery to the mating connector in the dual
fan/battery module and push the battery in.
5. Replace the module.
6. The electrical connection between the double fan/battery module and the control unit is automatically set.