Check Engine Light on SL320 - PeachParts Mercedes-Benz Forum

JerryWagner · #1 01-07-2006, 09:52 AM

My 1995 SL320 Model 129 with the M104 engine check engine light just came on, how can I find the code that is causing this without taking to a shop that will cost me a couple hundred bucks ? If I can find out what it causing the problem and replace the part it will save me alot of money, thanks to all in advance

bwheitman · #2 01-07-2006, 04:00 PM

Jerry,
Just do a search on a code reader, there are several methods of obtaining the trouble codes. I am not familiar with pre-ODBII cars, but as I understand there is a method of hooking up a light to the connector and counting the blinks to determine the trouble code. ODBII cars have a scanner you plug in and it gives a code number. I have seen several posts on people building ODBI code readers. Good luck.
Brian

deanyel · #3 01-07-2006, 09:24 PM

A 95 SL320 was an early OBDII adoptor and is supposed to be fully compliant - which should mean that you can go to Autozone and have the codes read for free. The connector must be within 3 feet of the driver. It also has a 38 pin connector for blink testing - this is under a little cap on the rear engine compartment, passenger side. You should be able to find more on Arthur Dalton's code reader with a search.

JerryWagner · #4 01-07-2006, 09:34 PM

Can I buy a code reader ? where can I buy one and where do I plug it in?

deanyel · #5 01-08-2006, 09:08 AM

You buy an OBDII code reader for about a hundred dollars or you can build the blink code reader for about ten dollars. Which code reader you get determnes where you plug it in. Have you checked to make sure you have both plugs? Again a search will tell you much about the blink code reader.

Arthur Dalton · #6 01-08-2006, 09:35 AM

The car is OBD1

http://www.autolib.diakom.ru:8000/CARS2/pribor/cs1000/manual/cs1000_mb.pdf

Page 12/13 , in particular...

bwheitman · #7 01-08-2006, 09:38 AM

Thanks for letting me know about the 95 with early ODBII connectors. That is nice to know. I thought it was just 1996 and newer, but I guess MB got a head start. I got my code reader at Pep Boys for 79.00. I don't shop at Autozone because they are not compliant to HRC guidlines.

bwheitman · #8 01-08-2006, 09:43 AM

Wow! nice document, thanks so much for posting that. I am going to print it for future reference.
Brian

Arthur Dalton · #9 01-08-2006, 09:53 AM

Quote:

Originally Posted by bwheitman

Wow! nice document, thanks so much for posting that. I am going to print it for future reference.
Brian

That one is the best...Used to be well kept secret..

Now you know them all..

BENZ-LGB · #10 01-08-2006, 10:02 AM

Quote:

Originally Posted by bwheitman

Thanks for letting me know about the 95 with early ODBII connectors. That is nice to know. I thought it was just 1996 and newer, but I guess MB got a head start. I got my code reader at Pep Boys for 79.00. I don't shop at Autozone because they are not compliant to HRC guidlines.

What are HRC guidelines????

JerryWagner · #11 01-08-2006, 10:12 AM

Where can one purchase this cs1000 scanner ?

Arthur Dalton · #12 01-08-2006, 10:23 AM

Quote:

Originally Posted by JerryWagner

Where can one purchase this cs1000 scanner ?

Why don't you just open the hood and see which connector you have .. ??

There is a sw there to cancel the CE lamp along with code retrieve.

JerryWagner · #13 01-08-2006, 10:28 AM

I will look tomorrow when I get back in town, what do you mean by "There is a sw there to cancel the CE lamp along with code retrieve."" specifically "sw" and lastly where do I look for these connectors ? again it's a 1995 SL320

deanyel · #14 01-08-2006, 09:50 PM

You don't want a CS1000 scanner - it would be overkill. If your car is OBD II compliant there will be a sticker under the hood somewhere that says "OBD II compliant, and there will be socket under the dash, under the steering wheel somewhere. It's a 16 pin socket, 8 on each side that looks a little like a parallel printer port. If you have such a socket this is where you would hook up the OBD II code reader (or have Autozone do it for free), which you would buy at any auto parts store, Sears, WalMart, etc. for about $100 give or take. The OBD II compliance is required as of 1/1/96, but some cars met the requirement early. I believe your car is one that did. It is my understanding that 1995 C280s, S320s and SL320s were compliant. But the way to find out for sure is to find the port.

But your car definitely has a 38 pin diagnostic connector. This is located on the rear passenger side of the engine compartment, right on the top. It is covered by an oval black plastic cover. Unsnap that cover and you will see a round cap with a nut in the center. Twist and lift that cap and you will see the 38 pin connector. The famous Arthur Dalton code reader, built from Radio Shack parts, can be built for about $10 and used to read codes from this connector. But what Arthur is saying is that some 38 pin cars have an auxillary switch (sw) to read the CE codes without the code reader. If your car has it there will be a pushbutton and an LED light near the 38 pin connector. To read the CE codes from here you turn the ignition on, hold down the button for 3 or 4 seconds and count the number of flashes on the LED. The number of flashes equals the fault code. Do the same thing again to search for a second code, third code, etc.

JerryWagner · #15 01-09-2006, 03:24 PM

I found it and it is the round 38 pin, I heard that you can jump certain pins and the Check Engine Light will flash with code, does anyone know this procedure ? I would try this before chasing down a code reader