Looking for suggestions other than lighting it up…
2008 Suburban ltz
195k miles
The other night, I ran into Home Depot and left truck running.
Came back to a flashing Traction control light, then I went to drive home (crossing fingers) the rest of the lights started going. Speedo was bouncing, and service everything was flashing… I pulled over and plugged in my code scanner and it threw 20 codes… as I was sitting there, I was hearing a clicking sound under the dash near the pedals, it was a constant pattern. I drove truck home and noticed the trans was shifting hard like it had a shift kit in it, wouldn’t down shift unless floored or manually shifted. It did drive fine just would not downshift.

Any suggestions? I checked the battery terminals, battery is fairly fresh, checked a ground under hood near the fuse block, I now have the battery disconnected to see if it would reset and maybe pull a code as to what faulted.

Ugh!

 

I figured id add to this,

Last night I put the battery back on, and it started right up, still had the lights on the dash. So i was going to take it for a quick ride and I noticed the clicking sound was happening again. Odd... I put truck in reverse and noticed the clicking sound again and it was consistent with the Reverse lights flickering.. <insert gun to truck here>

 

Did it throw any missfire codes??? There is a video out there where a missfire made a lot of the symptoms you are experiencing.

 

Problem resolved!!!!!

Above the spare tire was the ECU for the Ride control.. Unplugged that corroded box and tossed it, Filled plug with dielectric and bagged the connector.. Truck runs perfect and all the codes cleared..

I did remove the old Air ride and replaced it with the following kit last month:
Part #: ARN C2836
Line: Arnott Suspension

Truck rides amazing!