Hi!
I am new to MB's. I just bought one for my daughter from a girl headed to Germany for the Army. It is a 1993 400E. She said it runs good, but I am having a problem I just can't seem to locate. I trailered it home, just to be on the safe side. It ran great after I got it back to the house. I drove it about 15 miles, just to feel it out. When my daughter tried to start it the next time, it would start and idle OK, but when the accelerator is depressed and RPM's reach about 1000, the engine starts revving up ap and dropping back between 1000 and 1500 rpms all by itself. when you let off, it goes back to a pretty smooth idle, around 700 rpms. I checked around for vacuum leaks; the only thing I found was some gas in the vacuum line for the fuel pressure regulator. I figured it must have a cracked diaphragm, so I replaced it. No change. I bought a hand-held, LED code reader and pulled fault codes off the Internet. I scanned and cleared all the faults at the 38-pin connector from the diagnostic, base, LH-SFI, CC/ISC and distirbutor ignition modules. After clearing them, I ran the engine (same problem) and re-checked the codes. The diagnostic, distibutor ignition and LH-SFI modules all came back with the same fault- camshaft position sensor errors. The sensor was cracked, so I replaced it. Still have the same problem, but no more camshaft sensor codes. A couple things that make me wonder: The diagnostic module isn't giving me any codes, but will not give me the "no fault found" single blip. The CC/ISC module gives me a code 11, "fuel safety shutoff to LH-SFI control module", but I can't check it on the pins called out in the codes page. It says I should be using pins 1, 14 and 16 for the W124, but there is no contact in pin 14. I checked it using pins 1, 3 and 7. I don't know if this is a problem in itself or not. I have all the fault codes originally stored and after I cleared them and again after I installed the new camshaft sensor. Any ideas?

Bob Bowers (Erin is my daughter)
'93 400E (1st one)

On the pass. side next to the firewll there is a black cover that covers the control units. Remove the cover and you'll find the control units, the one at the rear has four 10 amp fuses (replace them all) and retry.
good luck, Mike

Reference to pins 1, 14 and 16 is for a six cylinder / 16 pin diagnostic connector while you have a 38 pin connector. You're on the right track but need to get the right code lists for your car - which is a 124.034. You may find them in a search or perhaps someone can post.

Page 12

http://www.geocities.com/MotorCity/Downs/1039/mercedes/cs1000_mb.pdf

I printed out the pages from the manual link provided; it is the same manual that I'm using for the codes. If I'm right, pins 1, 3 & 7 are the right pins for the CC/ISC module in this car. I'll run the codes from all the modules tonight and change all the fuses in the base module and post the details of my findings either tonight or in the morning. Thanks for the help and quick responses. By the way, is there a better scanner available for this car that won't cost me a couple grand. I saw some in the $200 range, but I'm not sure they could even connect to this car's computer.

Thanks again,
Bob Bowers

<< Still have the same problem, but no more camshaft sensor codes. A couple things that make me wonder: The diagnostic module isn't giving me any codes, but will not give me the "no fault found" single blip. The CC/ISC module gives me a code 11, "fuel safety shutoff to LH-SFI control module", but I can't check it on the pins called out in the codes page. It says I should be using pins 1, 14 and 16 for the W124, but there is no contact in pin 14. I checked it using pins 1, 3 and 7. I don't know if this is a problem in itself or not. I have all the fault codes originally stored and after I cleared them and again after I installed the new camshaft sensor. Any ideas?

>>
DM will not give any codes back after a clearing until the module has done all emmissions self-test..takes a few drive cycles [ FULL drive cycles]

Pin 1/16 are power for tool and 14 is EA/CC , but not for your car..those are code pins for 6 cyclinde/16 pin DM...124 chassis..nothing to do with your 8cylinder DM..you have 38 pin..124 chassis

Other modules have to re-adapt to mean. You can do this with drive cycles or after clear and code 1 appear, wait 2 sec, hold button down 6 secs, turen off key for 10, on for 50, start car.
That clears Memory.......menory and code clear are not the same at all....

Where did you get the Led tool you are using???

I bought it off Ebay; just a red LED and momentary switch. I was just wondering if I needed to be able to collect more data than the code reader can provide.

Oh..Ok
That is the one we make here..

http://members.aol.com/ajdalton7/ledtool.jpg

Just gets you a direction to a problem

But , a good reader is $$$ , so I would stay with that for now.
Codes are not a diagnosis, but an indicator... if you don't know how each system inter-relates and functions, they do not tell you the problem/cause. They just report what the modules are seeing out of norm.

OK. Changed all 10-amp fuses in base module and scanned codes. Also heard back from previous owner. She says the car had a new wiring harness, fuel pump, fuel filter and tune-up about 1 year ago. No problems since, until now. It sat a little over a week before I picked it up. All modules are clear except CC/ISC (still shows code 11: fuel safety shut-off to LH-SFI control module). It also threw code 6: starter lockout/backup lamp switch. This code I cleared. Still have the same problem.

That's the code 11 for a non-ASR car, the description a little different for an ASR car. The problem could be something as simple as throttle linkage sticking, especially since it started with non-use. You might try cleaning and lubricating it. You could also clean the throttle actuator. And make sure gas pedal isn't getting caught up in the carpet.

Sorry I've been gone so long, but i was out of town for over a week. I finally pulled the throttle linkage loose and cleaned and lubricated it. Cable assembly looks brand new. The rest looked a little rough so I brushed and cleaned it; it operates smoothly, no hanging anywhere, no excessive slack in any of the rod-end joints. Still the same problem. I did read that operating the throttle from under the hood can cause the car to have an attitude. I did this several times. Could this cause the fuel solenoid to shut down above idle?

Still hunting (and listening to Erin gripe )
Bob Bowers

Bob,

Although a different engine, I'm wondering if this is similar to a problem I had years ago (mine is non-ASR 94 e320)...

Check out my posts on 3-28-03 & 5-6-03 from this thread: 94 e320 Throttle actuator

Since then I haven't had any further problems...I've since replaced the throttle actuator and electronic module (EA/CC/ISC???) under the passenger floor. I'll have to check my records, but I don't think I can pinpoint a single repair that solved this problem...

Matt