[Spook50]

Quick question: would this be easy to troubleshoot/fix? The wife and I found an '06 Touring with 95K miles that we're seriously considering, but as mentioned, the steering wheel-mounted HVAC controls are inop. I'm trying to make up my mind if we should pass on the car, or if we could use it as a haggling point and I could fix it myself later on.

 

[inov8]

Do the steering wheel audio controls and horn function? Is the Airbag test light off?
All of these systems share a common component (the spiral cable, sometimes called clockspring).

I can only envision 4 possible points of failure:
The HVAC control computer - a new one will cost ~$240 (internet discount price).
The aforementioned spiral cable - ~$230 for the part.
The steering wheel switch assembly - $206 to $220 depending on installed features.
A connector not plugged in, or broken wire - $0 for the part.

I have yet to see anyone with this specific complaint on any Avalon forum, so I don't think it is a common problem.

Troubleshooting will not be easy due to difficult acessibility of the test points, but could be done. I would start by connecting various resistors to the comtrol computer input wires to see if the system responds. Yes means the control computer is probably OK; No means it is not. If yes repeat the test at the steering wheel switch assembly.

 

[Spook50]

Do the steering wheel audio controls and horn function? Is the Airbag test light off?
All of these systems share a common component (the spiral cable, sometimes called clockspring).

I can only envision 4 possible points of failure:
The HVAC control computer - a new one will cost ~$240 (internet discount price).
The aforementioned spiral cable - ~$230 for the part.
The steering wheel switch assembly - $206 to $220 depending on installed features.
A connector not plugged in, or broken wire - $0 for the part.

I have yet to see anyone with this specific complaint on any Avalon forum, so I don't think it is a common problem.

Troubleshooting will not be easy due to difficult acessibility of the test points, but could be done. I would start by connecting various resistors to the comtrol computer input wires to see if the system responds. Yes means the control computer is probably OK; No means it is not. If yes repeat the test at the steering wheel switch assembly.

Yeah, everything else works as expected. Got horn, radio, and no airbag light. From my understanding of how you explained it, it sounds like either a connector came undone or the button assembly is bad. Hopefully the latter isn't the case.

 

[inov8]

Unfortunately, the law of converse logic does not apply to this case. If the audio switches were also non-functional, it would have implicated the spiral cable, but working audio switches do not necessarily indicate the spiral cable is OK. It only takes one broken conductor in the cable to kill all of the steering wheel HVAC controls.

Toyota service info I have does not disclose if there is a separate connector in the steering wheel for the HVAC switch cluster. The other connectors between steering wheel and HVAC controller are all multiple-pin. If disconnected, something else would also be affected. So I think the unplugged connector scenario is at best a long shot.

If possible, you might ask the previous owner if any part of the steering wheel was recently removed (possible driver's air bag replacement?). It's easy to forget to make a note of the wire routing, and pinch/damage a wire during re-assembly.

You now know roughly what it would cost for a replacement part . . . all 3 possibilities are in the $200 - $250 range (plus shipping). Perhaps this gives you some negotiating leverage.

 

[mos805]

Are all of the lights working on the steering wheel? I had my clock spring go out on my old car and things just started going off gradually until everything just ceased to work. My old car didnt have hvac controls on the steering wheel but first to go was the audio then the bluetooth and last was cruise control. I started to be able to tell it was going out by the various lights that started turning off and coming back on. If it is just hvac I don't see it as much of a hassle anyways to not even run them, I pretty much never use them as I find the console mounted ones easier to change.

 

[Spook50]

It's sounding like troubleshooting this would be more difficult than I first anticipated. I'm thinking unless they take a good amount off the sticker price, we'll pass on this one.