I have a nbs 07 exc max pkg. I recently had to go through the trans and while doing put a 2200 stall vertor in it. While on a trip I stopped to get gas and then the truck would not start. I got towed to a gm dealer who replaced the battery. On the way back the trans went 200*. With a huge cooler on it, it had never done this.

I got it back to my regular mech to check and see if it was due to his work on the trans. Trans dropped, and verter replaced. Now the dod function won't operate. The shop says when the aftermarket xm radio was on it worked, when off it would not. They took the dash apart, cleaned some electrical connections and theings seemed to work. Now that's it's bacl together-no worky again.

Any ideas on what is going on here? Some computer not talking with another it seems. Help.

 

Does it work when you roll the windows down? just trying to think like the shop you use.

 

I drove it and when turning the xm off and on it does not work, nor rolling elec windows up or down. It seems there was a tsb about something similar and cleaning the computer posts so they did that and it appeared to work, but now with the dash back together-naw. I've chased a few electrical shorts before like this, but not with computers invoved.

 

I'm wondering it the connector for the DOD got damaged while removing and reinstalling the trans. It is right above the bellhousing at the back of the motor.

 

When the aftermarket radio was installed, did anything get connected to the serial data line? I've seen some aftermarket radios connected in this way(can't remember why), and it caused communication problems between modules on the car/truck. Also, IIRC, certain DTC's will disable things like the functions of TCC lockup and DOD.

Hope that helps you a little.