Code readers
 

Does anyone know where you can buy a code reader for my 380sl without taking out a second mortgage on my house. Also do you know what code do they use is it a mercedes only code. Thanks

If your car is 1996 or newer you can get an OBD II scanner from Harbor Freight. Check here:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94169

It often goes on sale on the their website for $39. If you print a copy of the online ad and take to the local store they usually honor that price. Regular price is $59 but maybe it's gone up in the last year.

Their are a large number of codes. Those that begin with a zero are generic for all cars. Those that begin with a 1 are model specific (ie Mercedes). Assuming your CEL is not on you may have pending codes. Use the scanner to clear them and wait to see if they return. If they do investigate.

Knowing the code(s) and their description often is not enough. Post any codes you have out here for help interpreting them. Good luck.

Mine is a 1984 380sl with the round plug. I have talked to several mechanics and none have any idea what we are dealing with. Its too old to be OB11 and maybe too old for OB1. I am about 90 miles from from the nearest dealer and don't want to go there anyhow since they don't want to work on anything over 10 years old unless they sold it. I had a good mechanic but he retired and sold his buisness to somw people from the mideast and I have not had very good luck with them. The last time I went to them they charged an arm and a leg and still did not solve the problem.

The Baum code reader book says about the round 9 pin diagnostic connector -

9-Pole Diagnostic Connector (1980-94)
The 9-pole Diagnostic Connector is used on earlier model vehicles. It can display
on-off ratio fault codes (1986 and later), RPM and Lambda sensor values. Various
on-off ratio Meters are available that provide access to this type of diagnostic
connector.

In other words your car does not have meaningful code reading ability. Even later 107s were primitive. You need a 129 body to have a worthwhile DIY code reading function.

Code reader
 

Thanks I was afraid of that

The only important piece of information from the connector is the duty cycle, which is on Pin 3. You can use a $30 meter with a duty cycle, or and old-style dwell meter to measure it. Tons of posts on how to do it if you do a Search.

What is the car doing or not doing that makes you want to read codes?

Best reply! mine as well..............that car doesn't have any code reading ability!

"What is the car doing or not doing that makes you want to read codes? "

When you shift from reverse to drive or drive to reverse the engine goes to 1200 Rpm and it takes about 10 seconds before it comes down to normal. It means that you have to wait in neutral to shift or tear something up

That would be an issue with the idle valve OR idle control computer.

Exchange of parts would be you best course of action.

Code reader
 

cclake;
As stated there is no "code" reading capability on your car.
In response to many complaints of harsh engagement from reverse to drive and vice versa Mercedes Benz incorporated a delayed engagement factor in the transmissions produced in the mid eighties. Use a stopwatch and time the engagement up to five seconds is typical.
Mike Freeman

There are literally dozens of posts on how to test the idle control system. Please do a search.

This Forum has had the advantage of time [ 10 years, I think] to accumulate so many post that I would bet it has the Largest Tech Data base in it's Archieves in the World.
So, we can not over-stress using the SEARCH FEATURE b/c we know the info is there ...and many of us have written so many repeat test procedures and remedies to the same repeated problems that we tend to not answer them anymore, knowing the same info is a click away.. Other forums WISH they had such a data base !!!!.....use it.
I just can't type OVP anymore......

Search and you Shall Find...........is is all in there , many times over

Idle control
 

Thanks again I have been thru about 4 or 5 pages of trouble shooting Using both the Mercedes manual and mercedes disc. They are different and can only see that the control box is slow applying voltage to the idle control valve. I was hoping to avoid just replacing parts without knowing for sure what is wrong. Acode reader if it had worked would have been offset by the cost of just the idle control valve,and it would have been nice to have. Once again thanks again I will just start changing parts when the budget allows it

<<9-Pole Diagnostic Connector (1980-94)
The 9-pole Diagnostic Connector is used on earlier model vehicles. It can display
on-off ratio fault codes (1986 and later), RPM and Lambda sensor values. Various
on-off ratio Meters are available that provide access to this type of diagnostic
connector. Call Baum Tools at 800-848-6657 or 941-927-1414 for more information
on these meters.>>

You can get a nice DMM at Sears w/duty cycle for $20...

This is the compellng argument for a 1990s MB, especially a late ODBI, like the LH 119s and the HFM 104s. And furthermore I'd say (seeing if I can start a fight here) for the DIYer reading fault codes late OBDI is actually better than OBDII.