So I stumbled across something strange tonight while I was just browsing the old interwebs.... the 2003 had a "Telephone and Mayday" system. I've "barely" heard about it and just wondering if anyone can shed any light on it's function. In another thread, I know it was discussed that the harness below the cupholder is part of this mayday system for the UK versions. If this harness is there is it safe to assume some of the other crucial parts of this system are also present? I also assume that on some level it ties into the phone dialer system of the Navigation. I'm not sure if 2003 was the first year this system was introduced or not, but am interested on any info anyone can provide. Also, I'm wondering if anyone thinks that these parts can be somewhat retrofitted to fit into a 2002. If so, which parts? Would it be plug and play? Anyhoo.... hope to hear what you all have to venture to suggest on this topic. I've attached a schematic link that peaked my interest. Thanks in advance.

http://www.lexussouthatlantaparts.co...roduct=5768380

 

The complete wiring harness is in the car for the telephone/mayday system...I believe it was used in Europe and Asia. It was anolog.

Back in the day I knew people who would listen to phone calls using a spectrum analyzer :-)

 

I wouldn't swear to this but.....

My understanding is that the Lexus Mayday was like GM's Onstar system. But Lexus designed it around 800 MHz analog cell phone technology, which was being eliminated in the United States, so it never made it here.

 

You could actually pick them up back then on the very low end of the UHF band with an old TV that had an analog tuner.

 

Could this be the same system? http://www.kddi.com/english/corporat...e/2002/0509-1/

Is there anyway to upgrade it to maybe pick up Digital OTA TV? Are all the components of this system still installed in the US SC430s? I know the Australian SC430's had an option for TV.

 

Sounds like the same thing. The mayday thing was a button mounted in the top tray of the center console box, at least according to the diagrams. It required a cellular telephone to also be installed. So, no, I am pretty sure only the wiring is present. My maplight didn't even have the microphone used by the cellular phone system.

Not sure what you mean. The mayday system? It was just a button that made a phone call over the installed cellular phone and could also transmit your location from the installed GPS.

If you have a way already of viewing video on your nav display, you should be able to get TV if you install a tuner. The U.S. uses ATSC for digital video broadcast. So to get digital TV, you would need an ATSC tuner.

As part of my CarPC install, I will have a dvb-t tuner as part of the system (but I will be using it to pick up scanners mainly.) There is software out there which uses the tuner as a generic radio, called Software Defined Radio (SDR) and can pretty much receive anything that is broadcast.

 

BTW, this system used the AMPS cellular system. The AMPS system is completely gone in the US as of around 2007, if I remember correctly. So purchasing all these components would be useless because you couldn't get any service.

 

Thanks for all the info... very, very informative. You really know your stuff, friends!! I guess I'm trying to ask a combination of questions. The first, where does the Bluetooth phone system and NAV dialer tie into our SC's? What part would need to be upgraded in order to add this feature to my 2002? Secondly, on those Australian SC's what component allowed them to receive TV in their vehicles (I was guessed it was this Mayday system, which is what spared my interest)?

 

No bluetooth. It was all wired. The actual phone came with the car and was permanently wired into the car. This wasn't any type of integration with your own cell phone. Personally, the phone system option is not all that interesting really. It was just a cell phone with a little bit of integration. It could be dialed over the IEBus by the nav unit for example. The audio came out over the rear left speaker and the mic was in the maplight. There was a handset installed in the center console for manual calls. I think to add modern phone integration, there are much better options. Just my opinion.

I have not looked at the TV system feature, but the Nav display uses SCART video. This is a standard that was (and is still I guess) used in many parts of the world much like our own composite video. In Europe nearly all the video equipment used in homes were SCART. So it was probably nothing more than a tuner with SCART video output that switched out the GPS video lines for the tuner. I have heard that there was also an actual DVD player (or a GPS unit that could play DVD movies instead of the map discs).

Recall that I had located the composite video input on the nav display, so there was already another video interface available and it is wired into the car. I imagine that this input could be switched with commands over the IEBus. The circuitry seems to support that with the video switch ICs installed. I think this is how some of the aftermarket video systems work. Others tap into the SCART lines and just switch out the GPS. They convert the composite video to SCART, which is actually a very common converter because people in Europe wanted to be able to use American equipment or vice-versa.

As for turning channels on the TV, it probably had a special navigation computer that had the tuner in it and software that used the touchscreen for changing channels. Just a guess. I have never seen this system.

That touchscreen control is the main thing you can't get by just installing your own tuner if you have an aftermarket video input. But it would be possible with a custom unit that could talk over the IEBus. If I weren't swapping out the whole nav system for the CarPC, I would have explored this avenue much further. But after looking at the image quality of the screen and realizing that the maps are so outdated, I realized I have no good reason to keep the existing system at all.

 

Look what I found in the Lexus manual!



One more...

 

If you open the rear console box, there is a cover that you can remove that exposes three connectors. I assume those are the mayday system connectors and possibly the mobile handset connectors. Been looking around for days for confirmation of that and pinouts. That might help.

The mayday switch panel is a whole tray that fits in the bottom of your upper console box. The mayday ECU appears to have its own GPS built in separate form the nav unit. But it does used the phone system.

Luxlink was not offered in the U.S. though, I thought.

 

The reason I need to know the pinout of those connectors is that I am planning to install something in that spot and would like to know what existing wiring I can use.

 

Did you purchase the wiring diagram manual for these cars?

Also, it is my understanding that the GPS antenna for the NAV system is located under the package tray. This 2003 manual only shows one location for the antenna.

I wonder why they would show the phone system in a US Lexus manual...if you have a set look at the cover page, where it says,
2003 LEX-US SC430

 

No. I purchased a subscription to the techinfo.toyota.com TIS system. Pretty much all of the diagrams you have shown are also there.

Would like to pick up a hard copy though.

 

GPS antenna in the package tray is for the Luxlink system. The NAV GPS antenna is in the dash below the front windshield.

Hang on, I will try to find the diagram and removal instructions again.