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

[The guitar zombie]

My 2006 Yukon Denali sat for 3 years. Everything worked back then except for an intermittent gas guage. The Car runs. The Code scanner will not connect to the computer (I had a earlier post on just the scanner, but now realize there’s a larger problem than just not being able to read the code scanner).

The radio volume is silent despite being on.

The steering wheel computer inputs do not work (display below speedometer) except the top right steering wheel button will only toggle between Engish French and Spanish (but won't let me select one).

The guages work (battery, = oil pressure) but the gas guage does not, except it reads empty with the fuel light on as Imput gas in it and did not move. In the past, when everything else worked, the gas guage was intermittent.

The check engine light is on.

I don’t think onstar works on the mirror.

The overhead light works, air conditioning and heat work (fans OK). Windows locks, everything else seems OK. The code scanner does do a successful battery check, but as stated will not connect for codes.

The above problems seem consistent and do not vary.

I am hoping there is a psychic out there that can help me or someone who can do a remote vulcan mind meld, but am willing to hear any other thoughts as spending too much on this 127K mi car is not worth it.

 

[Doubeleive]

My 2006 Yukon Denali sat for 3 years. Everything worked back then except for an intermittent gas guage. The Car runs. The Code scanner will not connect to the computer (I had a earlier post on just the scanner, but now realize there’s a larger problem than just not being able to read the code scanner).

The radio volume is silent despite being on.

The steering wheel computer inputs do not work (display below speedometer) except the top right steering wheel button will only toggle between Engish French and Spanish (but won't let me select one).

The guages work (battery, = oil pressure) but the gas guage does not, except it reads empty with the fuel light on as Imput gas in it and did not move. In the past, when everything else worked, the gas guage was intermittent.

The check engine light is on.

I don’t think onstar works on the mirror.

The overhead light works, air conditioning and heat work (fans OK). Windows locks, everything else seems OK. The code scanner does do a successful battery check, but as stated will not connect for codes.

The above problems seem consistent and do not vary.

I am hoping there is a psychic out there that can help me or someone who can do a remote vulcan mind meld, but am willing to hear any other thoughts as spending too much on this 127K mi car is not worth it.

first place to start is battery connectors/cables and accessible grounds, clean them all up with a wire brush even if they look ok.
also since it sat for so long look for any signs of critters chewing wires. look everywhere inside and outside, under the hood under the truck.
clean up the grounds at the same time.
as for OBD communication, verify that the cigarette power port is working, the power port & obd communication use the same fuse.
that's where you need to start.

 

[Fless]

Have you inspected and tested the OBD2 port as suggested in your other thread?

Don't forget about the in-cab fuse panel.

 

[The guitar zombie]

first place to start is battery connectors/cables and accessible grounds, clean them all up with a wire brush even if they look ok.
also since it sat for so long look for any signs of critters chewing wires. look everywhere inside and outside, under the hood under the truck.
clean up the grounds at the same time.
as for OBD communication, verify that the cigarette power port is working, the power port & obd communication use the same fuse.
that's where you need to start.

Thank you. I have not checked grounds but I will, and it makes sense. The cigarette (port?) lighter is working. and I checked all the fuses, in and out. And besides a few cockroaches, I didn’t see any obvious wire damage under the dash Or under the hood. But that doesn’t mean there isn’t any. After I check the battery connections, I will continue to look. It doesn’t sound like a computer problem to me, you?

 

[The guitar zombie]

Have you inspected and tested the OBD2 port as suggested in your other thread?

Don't forget about the in-cab fuse panel.

Thank you, yes I did. Also I checked the fuses to the left of the steering wheel as well As under the hood.

 

[Doubeleive]

Thank you. I have not checked grounds but I will, and it makes sense. The cigarette (port?) lighter is working. and I checked all the fuses, in and out. And besides a few cockroaches, I didn’t see any obvious wire damage under the dash Or under the hood. But that doesn’t mean there isn’t any. After I check the battery connections, I will continue to look. It doesn’t sound like a computer problem to me, you?

I would replace the cigarette port fuse just for good measure, as well as the accessory & accesory 2/aux fuse if equipped, even a poor performing fuse will cause problems, may pass a basic test but still not work "good", dirty fuse legs or poor electrical connection can cause problems
bugs could be a problem depending on how bad the infestation is.....

 

[S33k3r]

Take a look at the connections to the ECU. We had an issue where several of ours rusted, were poorly connected, or out right broke. We had a WHOLE bunch of stuff stop working at once. Other than that, you are testing fuses, relays, and wiring.

 

[The guitar zombie]

first place to start is battery connectors/cables and accessible grounds, clean them all up with a wire brush even if they look ok.
also since it sat for so long look for any signs of critters chewing wires. look everywhere inside and outside, under the hood under the truck.
clean up the grounds at the same time.
as for OBD communication, verify that the cigarette power port is working, the power port & obd communication use the same fuse.
that's where you need to start.

Please see my latest update, so far you were right, but I haven’t chased the potential ground problem for my diagnostic scanner Yet.

 

[Doubeleive]

Please see my latest update, so far you were right, but I haven’t chased the potential ground problem for my diagnostic scanner Yet.

I guess I am missing something.... what update?

 

[The guitar zombie]

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.

 

[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.