Another Nav diagnostic code

[Terpnut]

Wow, finally someone who COMPLETELY understands almost EVERYTHING that I have been ranting about for over two months now! As someone who has some user experiences with different Navigation systems, you can read about my constant complaining at http://www.cadillacforums.com/forums...?t=9906&page=1 (Navigation system malfunction?). I wish I could you help you somehow! Good luck in your efforts! Keep us posted!

[LymanSS]

Yes, there is a way to have auxilliary input. According to the shop manual I got from Helm there is a different version of the entertainment system that's installed on european export versions of the car. It has a set of RCA jacks right under the rear climate controls (at the rear of the center console on a DTS). It has wiring diagrams and I've been trying to figure out if our systems are simply missing the wiring. The system has a different part number but I don't know if there's much difference other than the wiring. Furthermore on the euro version there is a TV receiver as well as some sort of traffic info receiver that gets information on traffic conditions and re-routes you as needed. I'm glad to hear someone is actively working on figuring out solutions to the major complaints about the nav system. I also have a friend with a Toyota Prius which has a very similar system (also from Denso). He's working on the same problems. Being a comp-sci type I'm hoping he'll make some progress. I'll be sending him a link to your post in the hopes it'll move him along.

Scott

PS: if you want wiring diagrams and more info from the shop manual (assuming you don't have it already) let me know and I'll try to scan it and email it to you)

[SonarTech]

I saw that AuxTV input info as well, but couldn't do squat with it, so I disregarded it. I'd REALLY like to find out more about that, however...

I decided to dismantle my Nav system today. Just popped it out of the console, took it inside and immediately started disassembling it. Ahh... Felt good, I might add.

Anyway, I don't know if anyone else was stupi....errr, I mean BRAVE enough to do this, but I thought I'd post some info regarding the internals here. I also took pictures, but quite a few of them are crap because I was in a hurry and didn't have time to "tame" my digital camera.

My real reason for doing this was to put the final kibosh on those B.S. rumors that suggest that there's a hard drive in this farkin' thing. THERE AIN'T NO STINKIN' HARD DRIVE IN THIS PIG. If there is, it's half the size of an IBM MicroDrive and hidden under a metal shield. The other reason I took it apart was to find out what kind of CPU it used.

I'll clean my pictures up, annotate them and get them posted as soon as I feel the burning desire to reload Photoshop. Until then, you'll only get text, unless you specifically request otherwise.

As you may know, the Nav unit is totally self-contained. It's two modules stuck together. There's a top portion, that houses the DVD Slot Load Drive and the Nav Smarts. That's first on the list. The other module houses XM Radio and Radio Amps et al. Real exciting down there.....NOT.

Let's get to it. Remember - TOP to BOTTOM, in layers:

DVD Drive: The top Label of the Denso Nav System, GM Part Number 25755059, is surprisingly void of any kind of FCC ID. I thought that was VERY interesting. Anyhow, we'll work from the top of the unit down. After removing the gold Nav unit retention clips on both sides of the Nav Unit, I took off the very top cover. The DVD Slot Load drive uses Sony parts and is a model "DVS-2010". I couldn't find squat about it on the web ANYWHERE. I know that just because it uses Sony parts doesn't necessarily make it a Sony drive, however. The laser diode is an older part, circa 2002, which might explain some of the compatibility issues with home-burned DVD's. From the type of diode used, I'd say you'll likely have best luck using DVD-R's with this drive, but that's a guesstimate based on the electronics used and my rather antique knowledge of Sony electronics. Lots of super-fine springs in the slot loader. This is a pretty delicate and graceful doodad, all things considered. The control board for the DVD drive is attached to the bottom. It's relatively unremarkable for the most part, except to say there is an assload of test points on the board - ALL IN ENGLISH! The three major chips on the DVD controller board are as follows:

SONY CXD3008Q (CD Digital Signal Processor with built-in Digital Servo), SONY CXD1867R (DVD-ROM Chipset: 8x DVD and 40x CD), and Texas Instruments 19A2R7TAB (Power Reg for Laser?)

The Nav board (X25-8920-10) sits directly underneath the DVD drive controller and connects via a single 60-pin board-mounted header. It is still part of the top subassembly. The CPU and associated processing power are all located on the "bottom" part of the top subassembly. The cage surrounding the entire subassembly acts as the heat sink for the three major chips on this side of the board which are as follows:

CPU (IC201): Hitachi SH-3E, HD6417718R
UNKNOWN: "D" 151811-2470, T5L67F
UNKNOWN: "D" 151815-0740, T5U85FF-1012

I have no idea who makes these "D" chips or what they do. They're VERY LARGE chips, even bigger than the CPU. I gave you all the info that's marked on the chips. If you need a picture, let me know. The clock associated with the CPU is operating at 6.2936MHz. There's scads of information on the SH-3E RISC CPU, including a dandy Programming manual located at: http://www.eu.renesas.com/documents/...df/sh7700p.pdf

Now that we know what the CPU is (SH-3E), we should be able to decode the software. Anyone have a decent x86-based SH-3E disassembler? Since there's no hard drive in this thing, I'm betting that the file on the DVD called "LOADER.KWI" is the actual NAV/Radio/XM Radio program that's getting loaded into the NavSystem on startup. We need to disassemble this file with a SH-3E disassembler and look for instructions that would handle that "1791" code we already know about. Find that one and you'll probably be able to spot more in the same area, right?

There's also a Fujitsu chip here, IC109 with a big "V1.0" stamped on it. It's part number is MB89P195A. This series of microcontrollers contain various resources such as timers, serial interfaces, A/D converters, external interrupts, and remote-control functions, as well as an F²MC-8L(F²MC stands for FUJITSU Flexible Microcontroller) CPU core for low-voltage and high-speed operations. Furthermore, the MB89190AH is designed for applications which needs more high-current pins.

The other side of the Nav board houses the radio/GPS electronics. 90% of the components are housed under metal shields that I didn't feel like desoldering to gain access too. Sorry, I didn't want to take the risk of detuning my radio for the sake of discussion. The only real interesting thing on THIS side of the board was the 3V Lithium battery that's used to power the firmware/memory, presumably for manually-entered POI's and settings. It's providing power to a Motorola XC68HCS8xx where xx is either "DU" or "0W". Couldn't find it online; it's some kind of custom very-low voltage microcontroller.

Now on to the first board in the second subunit, directly under the Navboard. This is the display signal controller PCB. There's a long, white header on the side of this board that attaches to the Nav board - Kinda clutsy looking. It actually connects to the Amp board at the very bottom of the unit under the Display Signal Controller PCB. My guess is that these are the radio control signals for the Amp section / XM Radio Section. Anyway, Display Signal Controller PCB, part number X86-3400-10/J74-1174-22 is nearly void of components. There's a tiny Sony chip surrounded by filters, caps and other tiny SMD's. It's a Sony A1585Q S-Video to RGB decoder IC and a NTSC-grade 3.579565 MHz crystal. There's a small header at the front of the board that connects to the front-bezel header that in turn connects to the LCD display unit. There's nothing else on the other side of this board at all.

The last board in the unit is VERY busy. My guess is that it controller all radio-related functionality, including amp control, XP radio and tuner. There's a LOT of shielded circuitry on this board, as well as shielded modules attached to the board that extend up along the sides of the other PCB's in the bottom section, one of which is undoubtedly the XM Radio tuner. There's a chip central to all the activity on this board, made by Mitsubishi - M30624FGAGP with a "8P5" white stamp. This is a single-chip 16-bit CMOS microcomputer, ROM 256K bytes, RAM 20K bytes, which may act as all the RAM this stupid NavSystem has. I couldn't actually find any "real" RAM in this damn thing, unless it was hiding under one of the metal shields that I didn't wanna desolder. There's a number of smaller chips on this PCB, a piezo-electric buzzer (display open beeper), 2 smaller metal-shielded circuit boxes, and a GIANT metal shielded circuitbox that I think is the XP radio. This board is also responsible for handling the Class II data network in the car - the data pins from the external header attached to the board directly connect to that Mitsubishi microcontroller. There's also some very basic cross-over circuitry in this thing, and it's suddenly no wonder why the audio that this thing pumps out is medicore at best. God, I hope there a "real" AMP somewhere else in the car, like under my seat... Hmmmm.....

This board has two "wing" PCB's that are folded-over and attached via mylar and copper connectors. LOTS of filtering happening on one of these boards, part number J74-1165-22/X09-5350-10, which has the following chips: Motorola MC13020, ST Electronics TDA7400, TA (?) 2051FN and (?) BA3131FS.

The other "wing" PCB is actually the display signal controller PCB I already talked about. When folded over, it's the first PCB you actually see in the second subunit.

The final thing worth mentioning on the bottom board is that it houses the motor and gearing for the display panel opener. I see now that there's a current limiter circuit here that will reverse polarity to this bi-directional motor in the even the motor gets "stuck" while trying to open or close. That's nice.

Remember: I think the answer lie on the Nav DVD in the file "LOADER.KWI". While I wouldn't exactly stake my knutz on it, I'm still pretty sure!

...and for the last time -- THERE'S NO HARD DRIVE IN THIS DAMN THING. OTHER THAN THE MOTORIZED DISPLAY AND THE SLOT LOAD DVD DRIVE, EVERYTHING IN THIS UNIT IS SOLID STATE!!

Good night!

SonarTech

[compfan03]

Wanted to be the first one to thank you. That's a S-load of work you did. Hope it gets us somewhere. THANKS!

[Terpnut]

SonarTech,

Wow! Great job on taking apart the Nav system and your analysis! Here are a few of my thoughts or questions:

1. Who makes the SH-3E RISC CPU? Is SH-3E a manufacturer or chip OEM? Our shop does only Intel x86 software work so I'm probably not going to be very helpful here regardless.

2. If the bottom half of the system has an XM tuner, I assume Denso supplies GM with two different Nav system units (one with and one without the XM tuner). Or is it possible Denso only makes this one unit and GM only enables/installs an antenna for XM-equipped vehicles?

3. Since there is no built-in storage (i.e. lack of a hard drive), I agree that it is most probably that the nav system boots directly from the loader.kwi on the DVD. Can we test this by burning a copy of the nav system DVD WITHOUT the loader.kwi to see what happens? If the loader.kwi is the key to the kingdom, then you are right that reverse engineering and recompiling it is our best hope of disabling/enabling various features and additional customization. Of course, we could hope Denso/Cadillac will release a new and improved Nav system DVD soon, but I'm not holding my breath on this. BTW, the lack of built-in system storage obviously limits user-configurability and customization. For example, we cannot load the mapping data, POI's, routes and other data directly into the nav system, then use the nav system while simultaneously movies on the DVD.

Again, I appreciate your hard work and detailed report! Good luck!

[riff]

Lots of good information, thanks. I wonder if it's possible to connect an aftermarket XM to the head unit somehow so that I wouldn't have to deal with the FM Modulator. I'm thinking I'd need a software upgrade too though. I have to poke around myself and see if there's a way of doing it because I'd like my XM in digital quality... Any ideas?

I agree with you that the Loader file is the most likely source of the kind of information we're after.

Lyman: Can I take you up on the wiring diagram/schematics offer? I'd like to see if there's anything I can put my expertise to use with.

[SonarTech]

1. The SH-3E is a Hitachi product, as I said in my post:

"CPU (IC201): Hitachi SH-3E, HD6417718R"

I don't, however, know who makes the "D" chips which sit directly next to the CPU on opposite corners. I think they're custom ASIC's built specially for this Nav System. They probably also house the memory I couldn't find.

2. I THINK the XM radio's contained in the lower half, but I'm not even 50% sure of that. I didn't dismantle the metal boxes to find out. I originally thought they'd keep that out of this specific box, unless there's a GM requirement that you XM radio with the Nav system in your Caddie. I don't know that for sure, however. I only know of 1 puck antenna input to the back of the unit, and since that input goes straight into a metal can on the Nav PCB, I'm pretty sure it's GPS. If there's an XM-antenna attached to this box, it's part of another connector. Perhaps the actual XM radio itself is in another box elsewhere in the car, and the Nav box only tests for its presence on the Class II data bus and then makes XM radio options available in the menu system when present. That makes a lot more sense to me, now that I'm awake and thinking about it. There IS another box in the trunk between the back seet and the trunk wall next to the analog OnStar cell phone that could be it...

3. The Nav DVD is 5.8Gigs, I believe. LOADER.KWI is 7.something Megs. My blank DVD's are only 4.7Gigs, so I'd have to leave SOMETHING else off the DVD to make it fit. There's some interesting ideas, there, however - I'll give that more thought. Obviously there's a bootloader on the NavSystem that's looking for the Nav DVD. I wonder how it identifies it? My guess is that it's looking for LOADER.KWI. I have a 2003 Nav DVD, and I refuse to pay GM another $300 for a $8.00 DVD when I already paid to license the software by buying the damn thing. I can't believe GM thinks I'm actually going to pay hundreds of more dollars to get NavSystem map update DVD that cost them $2.00 to crank out. I'll post the file size and other juicy tidbits from my LOADER.KWI tonight when I have time.

Regarding the lack of storage space - you're absolutely right. We already knew there was a limit to the amount of POI's you could add to this system, and now we know why. That DID kind of bum me out about this Nav system. I was REALLY hoping I was wrong and that there was a hard drive in the thing... sadly, that was not the case. It will certainly cost us (as users) something in the future, because this thing is pretty limited in capability and functionality due to the fact it's completely solid-state. That also means it will become obsolete much sooner than a system that wasn't quite so "proprietary". The lack of moving parts does suggest that this Nav system will likely work longer since there's not as much crap to break. Car-based Hard Drives are nightmarrish to be sure... HEAT/COLD/SHOCK/MOISTURE, etc... BAD place for hard drives generally speaking.

I'm going to turn my attention to LOADER.KWI since the hardware's obviously not going to help us.

By the way, there were absolutely NO test interfaces, jacks or harnesses to attach any kind of test gear to. I was kind of hoping for at least a DB9 SOMEWHERE... :-(

SonarTech

[Terpnut]

SonarTech,

1. Sorry I missed the Hitachi reference for the CPU in your post--I guess I skimmed it too fast.

2. As for the XM radio, it makes sense that the XM tuner would be external and likely placed near the antenna. I assume, for the convenience of the assembly workers, a wiring harness from the front console to the rear XM antenna position already exists.

3. I thought all DVD's are 4.7 GB by the DVD Forum and other standards. Where did you arrive at 5.8 GB for the nav DVD? Is it a proprietary format?

I'm a bit confused about your reference to a $300 cost for a DVD from GM. For my Garmin StreetPilot III nav system, I paid $150 for an updated map CD after only about a year. I believe it is reasonable to pay for updated software and more current/updated map data (usually from NavTech). Did I miss something?

I agree that a hard disk is unlikely to perform as well as flash drives or solid state memory devices in the hostile operating conditions of a typical automobile. For example, my StreetPilot III uses 256MB CompactFlash--enough room for about 1/6 of the US maps and the base map. Although standard storage card devices (like CF or xD cards) have less storage capacity than a hard disk, they are however portable and can be easily read/updated by any computer, and thus may actually be preferable. In the ideal/future world, the nav system has both a rugged hard disk and a 802.11b/g wireless ethernet interface that would allow users to update/synch firmware and mapping updates wirelessly everytime your truck pulls into the garage.

[pagpc]

my acura's system would show elevation and lat. and long. can't get this system to do so. does anyone know how?

pagpc

[Terpnut]

Originally Posted by pagpc

my acura's system would show elevation and lat. and long. can't get this system to do so. does anyone know how?

pagpc

Between this and the other nav system thread, there are probably a dozen pages of posts discussing ideas on hacking this Denso nav system. Your request is just ONE of the many things we can't do with the nav system as it is currently deployed!

[SonarTech]

Originally Posted by Terpnut

SonarTech,

1. Sorry I missed the Hitachi reference for the CPU in your post--I guess I skimmed it too fast.

2. As for the XM radio, it makes sense that the XM tuner would be external and likely placed near the antenna. I assume, for the convenience of the assembly workers, a wiring harness from the front console to the rear XM antenna position already exists.

3. I thought all DVD's are 4.7 GB by the DVD Forum and other standards. Where did you arrive at 5.8 GB for the nav DVD? Is it a proprietary format?

I'm a bit confused about your reference to a $300 cost for a DVD from GM. For my Garmin StreetPilot III nav system, I paid $150 for an updated map CD after only about a year. I believe it is reasonable to pay for updated software and more current/updated map data (usually from NavTech). Did I miss something?

I agree that a hard disk is unlikely to perform as well as flash drives or solid state memory devices in the hostile operating conditions of a typical automobile. For example, my StreetPilot III uses 256MB CompactFlash--enough room for about 1/6 of the US maps and the base map. Although standard storage card devices (like CF or xD cards) have less storage capacity than a hard disk, they are however portable and can be easily read/updated by any computer, and thus may actually be preferable. In the ideal/future world, the nav system has both a rugged hard disk and a 802.11b/g wireless ethernet interface that would allow users to update/synch firmware and mapping updates wirelessly everytime your truck pulls into the garage.

Commercially processed Single-side, dual-layer DVD's can hold about 8.5 Gigs. Consumer-grade dual-layer DVD burners are just starting to show up on the market now (in the last 2 months) but media is extremely expensive and none of the burners currently available are capable of burning the exact same capacity of a commercially-prepared DVD. The NavDVD is not a DVD-R, it was prepared commercially. The total contents on my 2003 NavDVD come out to around 5.8Gigs. There are ways to actually cross-map files on an ISO image such that multiple file entries point to the same area in the ISO file. They could have done that on this DVD, but I seriously doubt it. I'll have a look at the DVD in more detail tomorrow and post what I learn. As an example I did for a class I was teaching, I created a single CD-R that had over 159 Gigs of data "on it", if you actually copied it to a computer.... There was actually only one 640Meg file on the disk, but there were 255 file entries all pointing at the same file.

The NavDVD itself is not proprietary - but the files contained on it appear to be.

SonarTech

[Terpnut]

Thanks for the explanation--I did not know that commercial grade DVD's are dual-sided.

[SonarTech]

Not all of them are dual-sided. Most, however, are dual-layer. You can have a dual-sided, dual-layer DVD, which means each side of the DVD has 2 layers, each capable of holding about 8.5Gigs. If a commercially produced DVD has a label on one side of the DVD (a color title or picture) it's only single sided. If the contents of the DVD are less than 4.7Gigs, it's probably only single layer.

Want to know more about DVD's?

http://www.cdcard-usa.com/image/image.files/dvdtech.pdf

[xstender]

Just got off the maiden voyage of my new SRX. The "1790" code worked the first time I tried it. While the baby was enjoying The Wiggles in the back the wife got to see Kill Bill. To cool!!! I Love This Truck!!!!!!!!!!!! Thanks

[sgilbert]

Welcome to the "club"! Just so no one gets confused, you DID mean to type "1791" right?