Lots of things don’t work on my 2006 Yukon Denali

[rockola1971]

As suggested, I cleaned the battery connections, despite them looking OK and the steering wheel toggles and dashboard display works now, but the OBDII scanner still doesn’t read. I don’t know where the ecm ground is, but I will look it up. Is it hard to get to? Also, I will unscrew and clean up the body/hood grounds, as the hood ground looks funky. I’ll update, with more thanks in the next few days.

thanks for your input.

Where did this vehicle physically sit for 3yrs? On grass/weeds? Pavement/rocks? Garage? Bare Dirt? I would be redoing ALL grounds, especially engine to firewall, the ones located below A pillar on the frame which are right where the firewall starts. The engine to firewall ground is common culprit for crazy BCM related chaos. Your instrument cluster likely needs pulled out and the rear cover pulled and clean the silver migration (gray/white) corrosion on the circuit board. Use isopropyl alcohol and a soft nylon brush/toothbrush to give a mild scrubbing. Your dead fuel gauge could be the stepper motor (what the needle attaches too) is dead OR a very common problem on this generation clusters is bad/cracked solder joints which will need to be reflowed OR your fuel pot is dead and its located in the tank on the fuel pump module. I know the tech II will tell which is the problem as far as either the cluster or the fuel pot.

 

[S33k3r]

As suggested, I cleaned the battery connections, despite them looking OK and the steering wheel toggles and dashboard display works now, but the OBDII scanner still doesn’t read. I don’t know where the ecm ground is, but I will look it up. Is it hard to get to? Also, I will unscrew and clean up the body/hood grounds, as the hood ground looks funky. I’ll update, with more thanks in the next few days.

thanks for your input.

There's on on the passenger side, at the back of the engine that's braided. It's given me fits before.

 

[ivin74]

If the OBD port does not work, check the fuses. If I'm not mistaking the radio fuse is on the same circuit as the OBD.