Brian,

Im trying to think of the best way to walk you through the process. After the first time you do it, you will be surprised at how simple it is. I see that you got your volt meter. Your gonna want another wire (probably 1 or 1.5 feet long. An alligator clip would be preferred, just would make it easier since u wont have to hold on to 10 things at once.

I take it you know where the connector is. Here is a picture of it and I highlighted the pins that you will be probing. Please note that the picture is reversed, because that is how we will be viewing it. The higher pins are on the windshield side and the lower number pins are towards the front of the car.



Now, I will tell you how to test. Set your analog volt meter to measure 12 volts (most likely 15VDC).

Before pullin codes, the key has to be in position 2 (dash lights on) and not running.

You have to ground the black plug on the meter, and then put the positive (red) plug from the meter into the appropriate pin your testing (see diagram above). I usually start with 4 and work up. You now need the extra wire. Have one end of it grounded (you can use the same place that you grounded for the meter). Place the red probing pin into the #4 socket in the car. If this doesnt fit, your going to have to get a large pin or bare wire and use it as an extension.

Once in the socket, the volt meter should read approx. 12 volts. (My #17 pin reads less, this maybe normal). Once u have a steady reading (steady hands), take the second ground wire, and touch it to the red probing pin thats in the socket. Hold it there for 3-4 seconds. Note: when you touch the pin, the volt meter should read zero. After you let go, watch the volt meter. IT should start to "sweep" or "pulse" as they call it. It is up to you to count the number of pulses. If it only pulses once, this is good. It indicates no faults. If you have an error code (anything over one), write it down. To find out if there are anymore error codes in that computer, redo the above procedure until the same code pulses. If the second time u do it, its the same as the first, then that is the only code.

To erase the code, take ur second wire and ground out the red pin while still in the socket (just like above), except hold it there for 6-8 seconds. After you do this, try to read the code (re-ground it for 3 sec.) and make sure it pulses 1, to indicate its cleared out. If you have multiple codes, you have to clear them out one by one.

I suggest, to make this process alot simpler, before you do it, get a piece of paper, and write down these:

PIN # ---------------- Web Link

4-----------------------------7
6----------------------------10
7-----------------------------9
8-----------------------------8
17---------------------------5

This will make it easier after the tests to reference your codes. When I say web link, im reffering to the internal links on the this page:

http://pages.prodigy.net/jforgione/MB_S500.html

You will reference your codes here.

I think I covered everything, but if you have any questions, please post them. Good luck and let me know what you find. Make sure you dont mess with any other pins in the connector. Follow the diagram.

-Andy

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