What with CELs popping up and people curious about A/F ratios and the ECU limping for break-in purposes, I wanted to pop this back into thought...

First off, it seems the 8 uses the CAN protocol as far as onboard diag goes, rendering some OBDII reader devices useless... :


http://www.rx8forum.com/showthread.p...ighlight=obdII


Anyone have recommendations/links to a good CAN reader that will connect to a PC (not just a PDA)?

Second...will your everyday device support the rotary 8? I know onboard diag is designed to be universal, but I can think of codes that would be piston engine-specific...is there a separate code set for the rotary? Do the devices have full functionality on the 8?


I've glanced at your run-of-the-mill OBDII readers...models like Carchip are somewhat inexpensive, and if I was buying a new car, I would like to have something like that where I can leave it plugged in and yank it out before it reset itself to kind of nerd over the readings and numbers and keep a comprehensive log/history on my PC. Could also be a good way to make sure the lot boys at the dealer don't take the joyride liberty (ie, "You can only take my reader off to analyze the car standing still...I have mileage recorded, and will check that and top-speed readings. If you need to run the car with your own reader for diagnostics, please contact me before proceeding.)


Thoughts, ideas, referrals, etc?

 

the rx8 has its own list of codes. i didnt look too close, but most appear to be generic. it does have codes for like the metering pump.

mike

 

Ever try to search for OBDII and CAN on the net? They couldn't have picked an acronym that didn't double as such a popular english word?

 

nope i have the service highlights book :D

 

Hi - what is the "service highlights book"? I'm interested in the CAN bus in general (being in the computer network biz) - can you point me to a source for this book?

 

This might be a good starting point.

http://commsdesign.com/design_corner/OEG20021223S0004

and

http://www.reed-electronics.com/ednm...1798/17df2.htm

Does anyone have a CARCHIP or CARCIP EX and does it work in the RX-8?? I talked to them and they are not sure but offer a 30 day money back. Certainly looks interesting. Info and manual are here and show connector pics and installation details:

http://www.ambientweather.com/Displa...asp?Search=Yes

 

The Carchip was the product I was leaning to buy a year back after looking around a bit, but I figured I'd wait because I anticipated buying a newer car in the future, and had heard things about CAN.

I don't see anything on carchip.com about it supporting CAN

Edit: OK, they say they're working on it, but currently don't support CAN. Sent them an email asking about their ETA, and any specific issues w/supporting the 8.

 

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex
communication line with high data communication speed and excellent error detection ability. Many electronic
control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.

I pulled this out of my 350Z service manual. I use Autotap to hook into my laptop from ODB-II port. It works with CAN but it is a little slow. It does work. I neat tech toy.
www.autotap.com

 

The Autotap looks pretty interesting. I can't tell if it's purely real-time or if, like the carchip, it can store information while you drive, and then you can plug it in afterwards for analysis? I would think that would be the most optimal.

It's cool they offer a Windows PC version with a serial connection, so you don't need a PDA or necessarily a laptop to use it.

 

Yes it is real time and it records them if wanted. It gets slower the more items you track (due to the CAN system).

 

Thanks for the info - who said RX-8 and Z guys couldn't co-exist in harmony? :D

 

where is the connection port located at? Is it somewhere around the steering wheel like most cars??

 

I picked up a RX-8 from our local dealer here to do testing on, and I was impressed. The RX-8 is a very cool car. Ever since I drove the car I have been trying to convince my wife to go for it.

There is a little bit of mis-information here. The Autotap does not currently support the CAN protocol. I know because I am finalizing the new CAN Autotap hardware currently. Due to software changes that also need to be made to support CAN, the full Autotap product won't support CAN until sometime next year.

The real time data update rate is top notch. Real time data can be gathered from the car at over 130 updates per second. That compares to other protocol which update anywhere from 5 to 40 samples per second.

The 350Z is not a CAN vehicle. It is still using the ISO-9141-2 protocol, which is the slowest. Most import vehicles use this protocol, but all vehicles will be CAN equipped by 2007. This link details which vehicles use which protocols:
http://etools.org/files/public/gener...s-02-17-03.htm

Jeff Patrick
Autotap Engineer

 

Well when I bought autotap that was the excuse your company gave as to why it was so slow. "Nissan uses a CAN system which slows the ODB2 information". We have been happy with our Autotap, but even our handheld ODB2 scanner is much faster at the real time data we track (timing, knock, o2 readings, etc). If or when you get a product that is better than the one I have now, please let me know. Still nothing is faster than Nissan Consult-II, but it is proprietary Nissan and cost $5000.

Oh and for clarification, the 350Z does use a CAN protocol for several operations, although not a full CAN system. For arguments sake, it is Nissans first attempt to incorporate the CAN protocol.

For example our TCS (traction control), ABS, VDC (Vehicle dynamics control), BCM (body control module), tire pressure sensors, steering angle sensors, unified meter and a/c amplifier all use CAN communication between components and the ECM. As a matter of fact there are 7 different possible CAN setups based on model and options.

This is the price we pay to be the first to understand a new vehicle. For the money we have spent on R&D for modifications on the 350Z, we could have another one laying around the shop. But it has paid off.

Adam (VandyZ)
Crawford Z Car Performance
http://www.crawfordzcar.com

 

I guess I mis-spoke. For OBDII purposes and according to what Nissan reported to ETI the 350Z is ISO-9141-2. Any automotive company can use any protocol they feel like for any operations other than OBDII, and obviously Nissan is doing that.

Jeff

 

Naw, I understood you. I just did not want to seem as if I misspoke about the CAN system. Clearly it does use ISO-9141-2 as we can use your product. Nissan has said the future CAN system is ready for use, but not support (Consult wont work with it directly). What I find is odd is how the CAN system slows the ODB2 information down, if it does at all. When I bought the autotap for all vehicles I knew very little about CAN other than Nissan saying it had it. I was not thinking that Mazda may be using CAN differently at this point when I suggested it.

 

I doubt that the ISO-9141 is any slower because CAN is present on the vehicle. That problem that I have been seeing lately is that multiple ECU's will reply to a request. The current Autotap software doesn't handle multiple responses very well, and the result is a slow update rate. Our version 3 software should fix this issue. The new software isn't due out for quite a while.

Jeff

 

I think there were some sources for CAN bus interface boards mentioned in a previous thread, if not, we use a Janz card, from Germany in many of our high speed conveyor products (if you want to do some of your own software work!)

FYI, when I heard the 8 was all CAN, I cheered! CAN is very fast and reliable. We are sensing events in our equipment that requires much faster responses than needed in automotive applications.