94 S500 codes
 

Just bought this 94 S500 with some minor front end damage, it has 119k miles, the interior is very clean, I drove it home and the next day went to get gas and then the check engine light comes on, I check codes and get 6, 9 & 18 I have a feeling they were already there and he reset the light before I got there, am I hosed are those codes going to be expensive?

Thanks Mike

Heres link of the guy you want to send PM he knows all about that model
http://k6jrf.com/MB_S500.html#MYCH

Hope this helps you out

Check out my Mercedes web page esp Menu#6 to decipher the Diagnostic Module (DM). DM #6 is the "badie" ... could mean a new ETA, Menu#24.

DM #9 = IAT sensor ...could be dirty or not there?? Clean with brake cleaner.
DM #18= probably a vacuum leak someplace ???

Reset all codes and drive awhile; see what comes back.

Son in law is here today he looked into the wiring harness and we discovered a lot of insulation missing on a few of them causing shorts, we are headed to the bone yard for salvageable stuff =) any thoughts?

Thank you for your help in advance.

I normally mention "changing the wiring harnes" but didn't b/c most all MBs between '92 and '95 have had the w/h replaced by now!

You MUST replace it before doing anything else. That in and of itself may fix all of the DTCs that are appearing.

Replace it, reset all codes and see what happens. :)

Ok replaced wiring harnes got rid of code 9 now just 6 and 18 left.

You should read the DTCs stored in each of the following ECUs; LH (pin 4), ASR (pin 6), EA (pin 7), Base (pin 8) and DI (pin 17). That should give a some further insight as to what is needed.

As I wrote, code "6" points to the ETA going or being bad. But that s/b confirmed by reading the other ECUs.

Son in law is at Radio Shack getting parts to make your tester, it has the mini type of pins. We will be testing very soon we will follow your instructions, you have been VERY helpfull thank you.

Mike

Ok here are the codes we got

LH = 13 & 25 (maybe that would explain the clicking noise on right side)

ASR light stayed on as soon as we plugged into pin 6 and would not blink

BASE = 6, 10, 11, 12, 13

DI = 1

trying to figure out why 10-13 would be on and the car runs, AC works and the belt is not broken or slipping

Thanks Mike

I have a good used ETA you are welcome to test with if you find internal or pigtail ETA wiring bad. Just shoot me PM if so.

Paul

Strange codes for the Base Module but that's what happens many times.

Replaced F1 in base module, then the ASR pulled up some codes 30 & 32. Cleared everything out and rechecked this morning have not driven it but came up with code 30 in the ASR. Oh did not mention this before but the speedo is not working or the MPG guage and no reverse :eek:

Mike

Update: took car for test drive and speedometer worked along with the fuel economy guage, pretty sure we drove it over 1 mile and did not see odometer move.
We did not get a response from pins 21 & 30.

One of the "ETA" going/gone bad codes . . #30 - - ABS w/ ASR Module: CAN bus to EA/CC/ISC faulty.

Not sure about the odometer . . . it's strictly mechanical . . a bunch of gears so they must be busted.

Not sure that there are wires connected to pin 20 . . . but 21 is the "Convenience Features" as I remember. But that ECU may be digital??

No "reverse"?? If it was a '96 or later, that could be related to a 'control-module' but the '94s are strictly a "gears-type" tranny so that implies that you may need some tranny work. Now that's REAL fun!!!

Ok thank you for your help my so in law will be gone for a week I will be on hold asking for help till he returns but just wanted to say thank you for you valueable assistance.

Mike

Son in law rewired the ETA it was in same shape as the wiring harness, we are checking to see what codes we get now. I have not given up hope yet we make a little progress everytime we play with it.