gx470 ahc/dac power issue (1 Viewer)

[jsoliz21091]

Hello all, this is my first post to a forum so apologies if not done correctly. I recently bought a 2006 gx470 and am having issues with the height control and dac systems.
The issue I am having is that there is no power to my controls inside it seems. The raise/lower, off, comfort/sport, dac all do nothing when pressed. No movement on the vehicle and no lights changing on the dash. There is also no lights on the actual buttons along with the shifter lights being out. The airbags do not leak and the compressor/sensors work by leveling out the vehicle when weight is added/removed.
Troubleshooting: I have checked/swapped the relay and fuse under the hood and the fuse under the dash. I've also reset the system by placing a wire in the obd port and pumping the brakes. I've swapped the ahc ecu on the driver floor panel. I've swapped out the physical buttons for dac and ahc controls. still no luck. Any insight to this issue would be greatly appreciated.

 

[Jstawgn]

The bulb are normally burn out. You can replace with LED. It's very small and I don't remember what is the bulb code.

DAC onky works in low range at speed less than 15 MPH.
Do you stil have adjustable shock? Most been replaced at this age and the replacement might be non adjustable.

 

[Poop Bubbles]

Are you certain you still have airbags?

 

[jsoliz21091]

The bulb are normally burn out. You can replace with LED. It's very small and I don't remember what is the bulb code.

DAC onky works in low range at speed less than 15 MPH.
Do you stil have adjustable shock? Most been replaced at this age and the replacement might be non adjustable.

the chances of the bulbs being out for all controls that also have no function when being pressed are small I imagine.

Dac is not working at all at any speed nor do any lights come on the dash when the button is pressed.

Airbags still level out when weight is added or removed. Airbags are still there

Are you certain you still have airbags?

yes I am certain the airbags are still there and functional

 

[muckitup]

"There is also no lights on the actual buttons along with the shifter lights being out" Do you mean the display in the console, or at the stick itself?

So:
Downhill Control Assist is unresponsive.
- No indicator light when button is pressed.
- No light from the button itself

Height Control selector rocker is unresponsive.
- I assume it's level is at "N" on the dash.
- I also assume that the "Off" button right below the rocker is not pushed in.

"shifter lights are out".
- no idea what powers those lights, though I imagine it woudn't be an ECU...but it could be.

You've checked fuses, reset the obd, and replaced the AHC ECU.
Have you checked voltage at the switches?
A scanner would be pretty useful for testing here. A good bluetooth scanner for your phone off of Amazon would work. you could easily test indicator lights and activate systems.

This PDF may help, if you haven't seen it yet. There's a wiring diagram for the DAC on "page" 05-887 in the troubles scenario section. Then skip to 05-891 "DAC INDICATOR LIGHT CIRCUIT (DOES NOT COME ON)"

https://lexusgxor.com/_media/general:2005_gx470_techinfo.pdf

Everything you've mentioned is tied into the SKID Control ECU, though you haven't mentioned everything that ECU controls. It could be something as simple as a wiring harness is loose.