I have a 2001 Jeep Grand Cherokee and the dealership told me I need a new PCM Module (Power train Control Module) at a cost of ~$850 plus tax and labor. I found the part on the internet for $336 but is this something I can replace myself? The service manager said this is basically a computer module. If I can replace a power supply on a PC it seems I could replace a PCM. Any advice? Thanks.