No Keyless/remote Start After Jump Start, 08 Yukon

kustomtunes · July 18, 2009

im a mobile electronics install professional for 6 years now and ran into a problem, i installed an overhead dvd player in an 08 yukon and only spliced into the dome light wiring. the power i got for the unit is self i got in the driver kick panel off of the main junction box. i always get accessory power from there because i have installed the gm aftermarket head rest and their equipment has a harness that plugs into this spot, i know better than to tag ingition harness, ..., in the newer gm vehicles. i never install anything am not sure about. that being said, here's the problem. next day yukon was dead. went and jumped off customer, and back at the shop we noticed the rear a/c was not cold. i check all my wiring and every thing was as it should be. started vehicle to check systems a/c was cold and had no more issues, then tried keyless and nothing, thought it might be the battery to no success. was dead again this morning. took to dealer ship and they could not read any codes (tire monitor was on as well), said it was the keyless fault causing the problem. im stuck i heard the dome light is the culprit for the battery draining, and this started on the newer platform so im gonna fix that, but any info on the keyless/code would be greatly appreciated, thanks for your time.

bill190 · July 19, 2009

I don't have a wiring diagram for an '08, so no telling what they have running to the dome light???

I do know in general there is a trend in new vehicles to use computer modules everywhere at the location of switches and elsewhere at the location of devices, then send data over computer local area networks from the switch's computer to the device's computer to turn on the device.

So for example there will be a "driver's door module" in the driver's door and all the switches in the driver's door go to this module. Then each other door will have its own door module. Communications between the door modules is via a GMLAN local area network. So from driver's door, roll down passenger window: switch > DDM > GMLAN > PDM > Passenger door window.

They even have computer modules in the seats!

So I would not be surprised if there is a dome light module now too?

They do this to save on wiring. Just a couple of local area network wires are needed between modules and power to each module.

Anyway new vehicles would have around 25 different computer modules, and 2 or 3 different local area networks. The engine local area network would be a high speed network for real time data. Upscale vehicles can have up to 80 different computer modules!

If I were you, I would get an all vehicle subscription to alldata.com Then you would have wiring diagrams for everything at your fingertips. Also if I were you, I would learn all I could about new automotive wiring. Nobody understands this stuff, so I see a BIG need in the future for those who can troubleshoot electrical problems in vehicles.

Here is a very geeky book on all this new electronic stuff...

Automotive Electrics Automotive Electronics by Robert Bosch...

http://www.amazon.com/Automotive-Electrics...h/dp/0837610508

kustomtunes · July 20, 2009

problem solved, computer did not like jump starting the vehicle, did a computer reset. keyless and warning lights went away, and everything works great now!!!