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Discussion Starter #1
My gf's car just threw an error code. I've always checked my error codes via the paper clip in the diagnostic port method (I haven't owned a new car since '96... :p ), but that, evidently, does not work with ODB-II cars.

I can get an ODB-II code reader from Pep Boys for $99, but I'm not going to do that if it will only ever work on my gf's car. So, the question is, will it work on my Elise (once it gets here.. ::grumble:: )? I seem to remember reading that it had some sort of encrypted can-bus or something - don't know if they are related.... don't know what a "can-bus" is.... don't know if it's even called a "can-bus".
 

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Yes, a standard OBD-II tester will work on the Elise.
I say this having never tried it myself, but I'm confident it would work based on the pinouts and ECU information posted here.

The Elise has two data ports.. an OBD-II data line, commonly called a "K-Line". This carries the "usual" compliment of parameters and error data that the generic scantools can read. The data is required by law now, and Lotus chose to make these items available via K-Line (but perhaps not CANbus)

The second data port is an HS-CAN port, and probably carries quite a bit more information than just the required OBD-II bits. It may not carry the OBD-II parameters at all, in fact.. it could be just a stream of love-notes from Lotus. It's alien technology.

SO... any OBD-II scantool you want to use should work fine for reading error codes and clearing them. I wouldn't expect to do much more than that.

I have a whole drawer full of OBD-II adapters for PC software, and some are pretty useful. If you're looking to buy a scantool, and you're laptop-equipped, I'd recommend going that route.. the software does much more than just clear errors and you can do some basic datalogging. Check out what's out there..

Again, all of this is just premature speculation on my part.. I'm anxious to get both hands on that dataport and milk it for all its worth..

Edit: "port" might be a bad choice of words -- both OBD-II K-Line and HS-CAN are physical lines on the one SAE J-1962 port in the car. So... one plastic port, two unrelated data connections.
 

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Where is the data port.

Ground Loop said:
Yes, a standard OBD-II tester will work on the Elise.
...
Again, all of this is just premature speculation on my part.. I'm anxious to get both hands on that dataport and milk it for all its worth..
Where is the ODB port?? i have an Autoxray 5000 scanner and i'd like to hook it up (just to see whats up)

Vince
 

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Ground Loop said:
The second data port is an HS-CAN port, and probably carries quite a bit more information than just the required OBD-II bits. It may not carry the OBD-II parameters at all, in fact.. it could be just a stream of love-notes from Lotus. It's alien technology.

Holy crap! I think you may be on to something. If we can tap into and decipher that data stream, I suspect that it will contain the ultimate Answer. Allocations, list positions, source of 'extra' cars, it's all there. Right under our noses!
 

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Re: Where is the data port.

demarco said:
Where is the ODB port?? i have an Autoxray 5000 scanner and i'd like to hook it up (just to see whats up)
Oh yes indeed -- and report back here!

The port should be under the dash, within two feet of the driver's right knee. You shouldn't have to remove any panels to get to it. It's in plain view somewhere under the dash.

Crane your neck and stick your head down at ass-height and see if you can spot a 16-pin trapezoidal connector. Heck you have the scantool, you know what it looks like.
 

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Discussion Starter #7
Ground Loop said:

I have a whole drawer full of OBD-II adapters for PC software, and some are pretty useful. If you're looking to buy a scantool, and you're laptop-equipped, I'd recommend going that route.. the software does much more than just clear errors and you can do some basic datalogging. Check out what's out there..


any recommendations?

I quickly came across this one http://www.digimoto.com

just starting to look into it - sounds like a worthwhile investment (not necessarily that one, but some sort of PC based system).
 

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Ground Loop said:
I'm anxious to get both hands on that dataport and milk it for all its worth..
Care to elaborate?
 

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Ground Loop said:
A picture might help:
Very helpful.

That would be the redundant ODB-Ia conical connector?
 

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I have this scan tool. I haven't tried it yet on the Elise, but I see no reason it shouldn't work. It plugs into my cheap laptop (a 75 MHZ that was given to me), and reads and displays things just fine. The web site isn't very good, but the software works just fine...

There are three (actually four) ODB-II protocols: ISO - for European, Asian and Chrysler; VP - for General Motors; WPM - for Ford (the fourth protocol is supposed to be for heavy equipment and marine usage, but I don't know if anyone actually uses it). Some scanners work with one of the protocols, some with two, and some with all three (mine does all three but I haven't tested that).

My scan tool has paid for itself several times over while troubleshooting problems with my '96 Ford Ranger. If you don't have a scan tool, it's a very good tool to have...
 

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I use the Auterra scan tool - which is for the Palm platform. It supports CAN and also includes some dyno software that has proven to be quite accurate.

CLICKY
 

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Discussion Starter #14
Thanks for the suggestions everyone.

I'm going the Tim route - not based entirely on price, but the fact that I can cover both cars for $142 doesn't hurt.

All these systems look very good, but the one Tim suggested, to me at least, looks like it's more closely supported & probably by a very small team (maybe one person) of very competent engineer(s). I am also impressed that he already has the Lotus in the database.
 

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BrianK said:
I am also impressed that he already has the Lotus in the database.
Lotus in the database? I don't know for a fact that it works with the Elise, but I would expect it to - it should just be the generic ODB-II codes which are universal. Manufacturers can add additional codes, in which case the scanner will report the error code number, but not it's explanation.

The "TRICOM - one piece car connector interface, hardware processing, for most vehicles $182" is the unit that I bought. I notice that he also now sells the "TRICAN - same as TRICOM with a Control Area Network (CAN) for all vehicles $240" for those people that want to monitor the CAN network. Also, I'll admit that I saved 20% off the price by having my son, a full time student, buy the scanner hardware for me...;)

When I get some time, I'll hook my scanner up to the Elise and make sure it does, in fact, work.
 

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Heh-Heh! Sh*te. I clicked on your Elan link, Tim.
I fink I wade a vewwy vewwy waad wistake.
I should not look at cars that start with the letters Lo...:D
Elan Sprint... Ooohh!
m [Elise Damm*t, Elise]
 

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andykeck said:
Holy crap! I think you may be on to something. If we can tap into and decipher that data stream, I suspect that it will contain the ultimate Answer. Allocations, list positions, source of 'extra' cars, it's all there. Right under our noses!
don't we all wish! They may even contain Dr. Evil's next world domination plot.
 

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Re: Re: Where is the data port.

Ground Loop said:
Oh yes indeed -- and report back here!

The port should be under the dash, within two feet of the driver's right knee. You shouldn't have to remove any panels to get to it. It's in plain view somewhere under the dash.

Crane your neck and stick your head down at ass-height and see if you can spot a 16-pin trapezoidal connector. Heck you have the scantool, you know what it looks like.
Well i just hooked it up. it works fine.

I tried it as a Generic ODB II and a Toyota ODB II.

Both worked fine. Just for kicks i took off the gas cap and rescanned, it came up with code P456 or something similar. (this is the code for a small leak in the evap system)

The autoxray scanner can also monitor the car while running etc.. that also works great.

Vince
 

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It appears that I am going to get myself a scan tool. I will at least get a cheap ODB-II, and maybe a combo ODB-II/CAN scan tool that connects to a laptop PC (for logging purposes). I still have yet to go through all the ones people have recommended in this thread, but I did find an inexpensive ODB-II tool that was not mentioned here.

From Harbor Freight:
Harbor Freight Cheap ODB-II scan tool
(I tried the link and it works. If it breaks later, just go to Harbor Freight and search for the word "Reader".)

Only $40, and it will clear codes as well. Here is the manual for it:
HF Reader Manual

Has anyone tried this one?
 

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Another question for the Elisetalk community in regards to scanners:

The main difference in the price of the PC-interfaced scanners seems to be the software package. The hardware from all of them is pretty similar, and most based on the ELM hardware. In fact, many of the vendors' websites state that their software will work on their competitor's hardware because the interface chip used is the same.

One of the big differences in the expensive packages from the cheaper ones is the dyno software. The expensive ones allow for drag resistance correction and SAE corrections. One even says that it will let you do a coast-down test to let it compute resistance parameters.

My guess is that I (we?) might be better off just logging time-stamped speed, reading the log into a spreadsheet, and doing the horsepower and torque computations myself, and apply corrections due to drag and SAE factors myself. Frankly, I am not sure I trust how the commercial packages do it. For example, one manual stated that for the car's frontal area, to just input the area as the height times the width of the car, and it will internally apply a 15% correction to account for the car frontal area not being rectangular. That is probably not accurate for the Elise. Hence, I would have to use the Elise's real frontal area and divide by 0.85 before inputting the area into the program. Those kind of things bother me.

So, my question is, does anyone have a sample spreadsheet that does those calculations already, or have the reference formulas, or know of one available on-line? That sure would save me a lot of time and effort (and the resultant mistakes), and help me save some money (around $90). If you don't have it all, can you contribute what you do have or know? We could make this a forum community spreadsheet tool.

So, inputs would be: (let's see if I get this right the first time)
- time stamped velocity (from OBD-II scan tool connected to a PC)
- total gear ratio (including final drive - test done in a single gear)
- tire parameters (outer tire radius with weight on wheels would be best and could be measured, or tire/wheel parameters to compute. Does the speed sensor use a front or rear tire?)
- temperature, pressure, humidity
- Drag info: either a coast-down on flat surface result or drag coefficient and frontal area (I think coast-down would be best if you can find a flat surface long enough, or use a short coast-down to compute aerodynamic drag plus rolling resistance. I assume rolling resistance is proportional to velocity the same way that aerodynamic drag is.)
- weight (with gas, occupant(s), and other stuff)
- correction factor for wheel hp&torque to engine hp&torque (15%?)

Did I miss an input?
 
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