So, over the weekend, I was driving home,and my head unit died out on me. It froze in the middle of a song and was completely unresponsive. The whole unit went off on me: the climate control, radio, and cd unit are all unresponsive. I have an '06 IS250 that's been well out of warranty, so my only option really is locating and fixing it myself (or paying someone boatloads to fix it for me). The only thing that works is the backlight of the very top of the unit (all the other backlights are off), the emergency light button, and the security red LED that blinks. When I turn the car to ACC, I can hear a faint motor sound that comes from behind the unit (sounds like it's almost from the engine bay). I'm not sure if this is relevant at all, but I'm noting it anyways. In addition, my tachometer middle LED is dead intermittently. Every now and then it pops on for a little bit (couple seconds) then turns off again.


So far, for troubleshooting, I have tried the following:
1. Checked the radio fuses (rad1-3) with a DMM. They all are good, but I tried replacing each individual fuse with a spare anyways, with no results.
2. Disconnected the battery and reconnected it an hour later, still no response.
3. Removed the unit to check the connections on the back. Everything looks fine.

UPDATED:
I tested the unit in my friend's IS, and it works. So there's something wrong with my car. I'm at a complete loss right now. I have no idea how to go about troubleshooting anymore.

 

Bump. Still looking for help

 

I know you said your unit works on your friend's car, but if you ever need another one, I'm selling my climate control under classified ad section.

Good luck.

 

Unless you are comfortable digging into the wiring and electronic systems on the car I think you will have to defer to your Lexus dealer to try to troubleshoot the issue. It might be something relatively simple, but I'm not sure how you will find the problem on your own.

The Nav unit is one of the main reasons I took a four year VSA on my 06 Lexus which will get me eight full years of coverage. Anyway, good luck.

 

Try checking the grounds, they might have come loose or worn (how I would not know) so it could be shorting out the unit somewhere.

I had this issue when I installed an Amp before, I didn't get a good ground and the whole system shut down while driving.

 

Damn I was almost 100% sure it was your unit till it magically worked when we swapped it

 

Have you found resolution to your problem?

 

^He did

 

What was the issue? What fixed it?

 

I am curious to know the solution too. Based upon CL, it seems rare that these units fail; the only high failure rate is the LCD screen. Everything works but the screen will be unresponsive.

And since the OP doesn't have navi, im surprise his unit fail at all.

 

im almost positive it was wiring correct? ive done a couple dash harness' due to problems similar to this one.

 

I had a similar, but somewhat different problem where only the top lcd lit up and none of the center console buttons were responsive. It ended up being an aftermarket amp the previous owner installed. I took it off, and returned the vehicle wirings to stock and it worked perfectly. Did you have any aftermarket installs?

 

Curious as to what was the cause of the original posters issues.

My 250 has just started having intermittent failure on the head unit. It may become unresponsive for the whole journey, 5 minutes or it might respond 10 seconds after I hit the button. My first indication that it's acting up is that all info will disappear from the radio display. I can still power on and off the radio/ switch to aux etc. but the lcd will remain blank. The CC will be totally unresponsive during this.

Bringing it to my dealer on Tuesday and any info I could get in the mean time would be much appreciated.

 

Same thing happened to me, it was a fuse that blew. Go in your passenger side seat and look under the compartment, you'll see a little fuse box. I replaced the one that controls the navi (can't remember what number) and everything worked perfect again. Look in your manual for the fuse number.

 

Thanks TuReckless