Typhe

iTrader: (1)

Hi all,

1) My steering wheel mounted audio control buttons (volume, mode, etc) and AC Controls (Climate button on Nav, ALL AC buttons located above Nav like Temp Up/Down, Dual Climate Control, Defrost, Rear Defrost) all stopped working at the same time. When I press any AC-related button, I get an error message on my Nav screen that says "Check the Connection of AC."

2) I took the car to Lexus to diagnose. They told me that the culprit was a faulty Navigation system. I would need to replace my entire navigation system: Screen, Navigation Unit, and Navigation DVD.

3) I posted my issue here on the forum a few weeks ago. Brian (sakataj) was extra helpful in helping me with replacing the Navigation Unit in the trunk (gen4), updated Navigation DVD, AC ECU (located on the back of Navigation Screen), and he even provided a Navigation Screen for me to test, since Lexus said mine was bad. Even with all components replaced as Lexus advised, I still cannot use my steering wheel mounted controls or AC buttons.

4) Brian suggested I check all of my fuses. I've checked under the hood and driver/passenger fuse panels. All fuses look fine.

After all of this, I do have a pretty new Nav Interface, thanks to the upgrade from Gen2 to Gen4, but I still have no AC.

Does anyone have ANY suggestion on what else can be checked???

sam12345

iTrader: (1)

Welcome to the world of multiplexing

Typhe

iTrader: (1)

I'm willing to try ANYTHING at this point. Funny how everything else in a car seems unimportant when driving in 90+ degree heat in the South with no AC.

neegroy

iTrader: (19)

maybe its the ac condenser?
did you check all the pippings?

sam12345

iTrader: (1)

I have a nnon nav ac control that I can send you to see if it's the ac control or something else. But you would have to pay the shipping. You can then send it back.

Typhe

iTrader: (1)

I haven't checked the condenser, neegroy. Got the entire AC system replaced last year. My mechanic has confirmed that the AC system is still working fine. I just can't control it from my dash.

Typhe

iTrader: (1)

Hi Sam. That's another solution that Brian suggested. Send me a pm on what I need to do. Thanks

sakataj

iTrader: (182)

ok lets break these down into individual posts for me to not jumble up my responses

1)im fairly certain there is a wiring issue now being that you have replaced the nav ecu, the a/c controls,and the screen with ones from my car that were working....i still have a few thoughts about this though,remember that picture of the steering wheel i sent you, the wiring/box inside the steering wheel could be bad and if you checked all the fuses as i suggested and they are all good im not sure what else could be left besides a wiring issue.

2)i think we def disproved their "diagnosis" since you did replace all of those parts

3) i can "loan" you my steering wheel controls to see if new ones would fix it (but if your gonna go this route i think it would be worthwhile to try another wheel (since the steering wheel controls do run through that housing attached to the wheel......i can loan you all these things but unlike the nav screen and such i sent you, i do need these back

4)i dont mean visually check them from the outside, i mean start pulling fuses (especially underhood and manually checking them)

im just curious as to why your diagnosis would be the a/c compressor or a/c system here...neegroy? from our conversations i know barry had all this replaced lately due to another misdiagnoses from another mechanic. his issue is its just not sending a signal to turn it on.... (barry, have you tried to see if they can hardwire it on to force it on to double check over it....although i know you told me it was working when it suddenly did this but its worth a try)

thats the right kind of help i remember CL offering sam.....but although i did suggest this to him before sending him my old nav ecu controls if you think through this, this isnt gonna change anything (although im sure he's not againsnt trying anything at this point).... here what i base that off of....if his nav ecu controls were bad then mine which barry and i knew to be working would have fixed this but when he plugged my old ones in, he still is getting the same "check a/c connections" issue which is why im starting to lean towards him probably having a wiring issue and it might be time to break out the old multimeter and start tracing wires for "breaks"

i wish i was local barry i def would be all about helping you, keep me informed and we'll see if the combined minds here cant help you get this fixed

sam12345

iTrader: (1)

What about body ecu? I have two spares left and right side. Should I send him one of those?

sakataj

iTrader: (182)

like the door ecu's? im not aware of them controlling anything for the audio/ac, will have to look over some PDF's when i get back in town (barry is also out of town so i dunno if he has looked over this yet or not)

i need to upload the pic of the bare steering wheel i took for him and show you those...i think its either in there or a wiring issue.....i really do wish he was local i could help him trace the wires which will cost him a fortune at a shop

sam12345

iTrader: (1)

No, not door ecu body ecu, the ones that are behind each fusebox

sam12345

iTrader: (1)

Here are some links related to the pm I sent you

http://www.ehow.com/how-does_5003955...ule-work_.html

https://www.clublexus.com/forums/gs-...al-issues.html