Electrical Problems 07 Denali

[mentalattica]

A friend of mine has a 07 Denali that has been having what sounds like electrical issues. It started the day she got her battery and alternator replaced. First the low coolant alert, then service stabilitrak, next was the AC started blowing hot on the passenger side and cold on the driver's side. Lastly the truck went into limp mode. All of this happened within about 5 minutes. Turned it off, and the same thing happened when she started it again.

She took it to the dealer who told her it was gonna cost her $120 to diagnose each thing so just diagnostics were going to cost her $480+ tax. I told her to go pick the truck up and take it to a local shop. When she went to pick it up to avoid the outrageous diagnostic fees they told her they knew what the problem was, it was (in her words) "some kind of transmission switch."

Does this sound right?

 

[BRUTUS_T_HOG]

Disconnect the battery for at least 5 minutes and reconnect firmly just to see if it makes a difference. It sounds like when the battery was reconnected it did not make firm contact the first time and may have caused one or more modules to freeze and start putting corrupted data on the network.

I have seen this on many vehicles.... Ford, GM, Chrysler, Land Rover, ect... funky stuff happening all because a module needs to be completely discharged and rebooted

 

[mentalattica]

Thanks for the reply.

I think that may have done it.

 

[livingez_123]

That would be my first suggestion also, disconnect the battery. the ECM's are so picky to voltage and little spikes.