OBDII Scanner/Reader Recommendation - PeachParts Mercedes-Benz Forum

MBDad777 · #1 06-12-2003, 01:38 PM

Looks like it's been a while (click) since anybody addressed this, and I'd like input on sub $200 OBDII code readers. Which features are important and which models should be avoided? And what is the difference between a simple "code reader" and a full-fledged scanner?

I've had CE lights come on in my various cars four times in six months and it might be time to get a reader/scanner. I know Auto Zone offers to read the codes but there's also the implied obligation to get your parts there. I want more flexibility than that.

manny · #2 06-12-2003, 03:12 PM

I can only offer you limited input on this topic.
A " code reader " is what the name suggests, i.e. you can retrieve stored trouble codes, but still need a description for each code.
A " scanner " normally allows you to observe " live data stream ", i.e. you can see what's happening, while it is happening.
If that makes any sense.

#3 06-12-2003, 03:50 PM

If you have a laptop to use for this, go to obd2.com and look at the EASE Diagnostics products. I have the personal version and it works well. You will need a bright screen laptop unless all your use will be inside the shop. Out in the sunlight, the display on the older laptops is too weak.

Good luck,

MBDad777 · #4 06-13-2003, 12:56 AM

This one looks pretty cool (click here). You plug it in to your computer and get streaming data and periodic updates.

MBDad777 · #5 06-13-2003, 12:58 AM

Here's a screen shot.

#6 06-13-2003, 07:15 AM

I quickly perused the site and at first thought "well, that's real good but what about the software?" Then I found the free download.

For the money, this might be a practical solution for a DIYer. Remember though, you will need a newer laptop with a bright enough display to be used in a car. You will also need a good battery or a cigarette lighter cable.

Good luck,

KenP · #7 06-13-2003, 08:36 PM

This is the system I'm using on my 1996 S500 and it works great.
You're right about needing a decent display... an "active" screen is a necessity in bright sunlight... even then you need to shade it some.
But, you don't need a "newer" laptop... good news is that the data rate from OBD2 is extremely slow... so just about any laptop can run the data and feed the display. It runs fine on a 486.
I'm using a HP OMNIBOOK 800 with active screen. Its several years old (they're easy to find pretty cheap), is much smaller than most laptops at 3 pounds, and is a Pentium 166.
The really cool part is the power requirement for the OMNIBOOK 800 is 12 volts DC... :-)
The cheaper way out is an OMNIBOOK 600CT... the older, 486 version...
The best thing about the software (besides being free!) is that you can scan several functions at the same time... you can even run the O2 sensors plotted against trim all at the same time.
KenP

#8 06-13-2003, 09:12 PM

The only reason I suggested a "newer" laptop is for the brighter screen.

Have a great day,

KenP · #9 06-14-2003, 06:26 AM

Yep, I thought that was the reason, but wanted to make sure folks knew you could get by with an older (and cheaper!) machine...
A bright display is certainly preferable... and can be had on an older machine if folks look around. You can often find these for less than 100 dollars.
My "dedicated" HP laptop gets used as the scanner and also its a neat place to keep service records, illustrations, etc... all in one place.
A great day to you as well.
KenP

MBDad777 · #10 06-14-2003, 12:22 PM

I ordered this (the BR-3) yesterday for $88 including Priority shipping. I also ordered a 50' serial cable so I can plug it right into my desktop PC. I'm tired of the hassle of getting my OBDII scanned by someone else and hope this will give me an in-depth analysis of my O2 sensors.

This appears to be basically a small (one-man) startup-company with a good product, so hopefully it's not a cheap scam!

Thanks for the input Ken and Larry.

Dan

KenP · #11 06-14-2003, 04:24 PM

its definitely NOT a scam... I've had mine for over a year... came pretty quickly after I ordered it. Looks identical to the picture on his web site.
Very easy and intuitive to use...
Not sure you'll be able to get enough signal over 50ft of extra serial cable, but you can try.
It definitely will allow you to do a detailed evaluation of your O2 sensors... and will plot the data real time for you.
Let me know how you like it... its a bargain IMHO.

Now, if only we could get something similar to read the 38 pin connector digital signals for the rest of the Mercedes system...

KenP

stevebfl · #12 06-14-2003, 09:29 PM

Besides not working on anything but engine management, an OBDII scanner is just a fraction of what can be done with the proper tools.

The real ability to diagnose the modern system comes from being able to manipulate the system while watching the proper data. There is no manipulation with OBDII. Even the data is mostly irrelavent. MBs have about 4-5 things involved with thenthgrottle action. A OBDII will be lucky to give more than a single PID for throttle.

A proper scanner would allow one to view the variation in power driven crankshaft acceleration rates (misfire). The number has a threshold, which when passed will trigger an OBDII P03xx code. With OBDII thats all you get is the code if it registers. With a proper scanner one can reduce the fuel by 7% increments and see if the misfire factor changes on a cylinder (or more or one can add fuel - either way to over 29% difference). The same can be done with timing control.

Evap, EGR, and Secondary air codes are about impossible without the ability to engage the systems and monitor the critical factors, none of which can be done with OBDII.

I would say that having an OBDII tool is about 10% of what a real tool will do on engines and nothing else. if one were to want a tool that did about 70% on all the major systems for a serious DIYer (one not just in it for the money) one should buy a Snap-On MT2500 on ebay (a complete kit cost me $4k in 1995) for less than 500 and then buy new or on ebay the MB module. New could be almost another 500.

The best deal going on the real thing is the BASIC from MB. it goes for about $9500 plus a few thou a year for updates.

MBDad777 · #13 06-20-2003, 07:36 PM

Quote:

Besides not working on anything but engine management, an OBDII scanner is just a fraction of what can be done with the proper tools.

In spite of "not working on anything" but engine management, a scanner opens up a whole new world for the DIY'er who likes to wrench on his or her own vehicles. Very few people have the training, facilities and tools to perform a "true" diagnoses with the "proper tools."

I got my BR-3 scanner two days ago and it is absolutely wonderful.

Can anyone say "wet blanket?"

stevebfl · #14 06-20-2003, 07:54 PM

Just like a child when he first learns to read.

The problem with realizing boundless knowledge is that real soon the boundaries become visible. Make a few bad calls and you will blame the tool if you understand. If not you won't realize that there really is test procedures.

And how will you deal with the rest of the car. I use a scanner about 30% of the time for engine management issues. The other 70% won't be accessible.

With that said I use OBDII scanners all the time, for quick specific reasons. Never for diagnosis. It would be like tieing both hands behind my back.

KenP · #15 06-20-2003, 08:22 PM

Dan, glad to hear you got your interface box and that you're happy with it. By now, you realize that its much more than just a scanner that outputs DTCs... it gives you real time access to some of the engine management data stream... as well as letting you see the output of a number of sensors (air mass, temp, etc) under the hood. You gotta try it with a laptop while somebody else drives the car... neat to see the system in action.
I understand Steve's point about much more being available if you have the proper tools and knowledge... but you'll have to agree that 10% knowledge of what's going on under the hood is 100% better than 0%. I would never pretend that this tool would take the place of other gear. For that matter, I don't think any amount of tools will ever replace knowledge and experience.
He's also correct (of course) that it doesn't do diagnosis... but, it sure has helped me track down some problems. When the CE light is on, the DTC says the mixture/trim is out of spec, and the output plot of an O2 sensor is flat, I think that's pretty compelling information for diagnosis of the problem.
Additionally, for guys that want to understand what the engine management controls do and see what the outputs look like, its an invaluable training/learning tool IMHO. I really like the displays and the plotting capability.
As I said, I've had my interface for some time now... and am now looking for a good used MT2500 so I can learn more...
Yep, like learning to read... but, you gotta begin somewhere... and the price is right.
Just my 2 cents.
KenP

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