I have a 1994 E320 with M104 engine (non ASR) at ~160k miles. When I purchased the car the previous owner told me the cruise control actuator was bad so I have not tried to use the cruise. The car seems to run fine but has a slight hesitation when accelerating (forward or reverse) from a stop. The CE light is on. I made a code reader from the diagram posted on this forum and pulled the codes, they are:
Pin 3:
code 3
Idle speed control faulty

Pin 8:
code 8
Idle speed control (ISC) system at upper or lower control stop or CC or EA
indicates "limp home" mode.

Pin 14:
Code 2
EA/CC/ISC control module (N4/1) or Safety contact switch (M16/1s1) or Stop lamp switch or Cruise control switch or Actual value potentiometer or Starter lock-out/back-up lamp switch or engine speed signal or vehicle speed signal or closed throttle position switch or safety relay in EA/CC/ISC control module
Code 11
Closed throttle recognition signal to engine control module (HFM-SFI or Left LH-SFI) Fuel safety shut-off to engine control module (HFM-SFI or left or right LH-SFI)

(Please note that I used the code definitions from a post on this forum but they differ from those in the CS-1000 scanner pdf. In particular for pin 14).

I am not sure what to do at this point. I tried to search for ISC but did not find something specific. I hope there is something I can check to make certain my throttle actuator is where the problem is before spending $500 on a rebuilt one at "4mercedes.com"

Can anyone help interpret these codes?

Thanks,
Jim

Jim, before we dig into the interpretation, did you clear the codes to see which reappear? Some codes can be spurious and have no serious consequence. It takes a few days of driving to go through this iteration.

No, I did not clear the codes.

Up to this point I have checked pin 3 code = 6, on 3 separate occasions.

I will clear the codes and check after driving tomorrow.


Jim

Inop cruise control and codes you listed indicate defective throttle actuator. Just to be sure, clear codes and see what comes back. I went through this same problem a few years ago, there is a lengthy thread with all the details. A search should find it.

(If you are a very handy DIYer and have good soldering skills, you might be able to rewire your own actuator. Somewhere there is a thread detailing how to do this.)

J. M. van Swaay

__________________
1994 E320 Wagon, 230,000 miles
1995 E320 Sedan, 106,000 miles
1994 E500 Sedan, 79,000 miles

I can not clear the pin 3 code (value is 6) (I am not sure if pin 3 is the same as the push button at pin 2). I understand the directions to read the code then hold the push button within 10 secs and was able to do this for pins 8 & 14, but could not clear pin 3 code 6. I tried many times, I cycled the key switch, but it would not clear. I also tried using the push button at pin 2 instead of the home-made code reader tool. The check engine light was off after I finished and is still off when I arrived at work this morning.

How can I clear this code?

Jim

I drove the car approximately 15 miles and upto speeds of 60 mph before the CE light came back on. I drove and parked, drove and parked, drove and parked and when I went to start the car again the light was on.

I checked the codes when I got back home and found the following:
DTC = 6
Pin 8 = 8
Pin 14 = 2

As before, I was able to clear pins 8 & 14, but not the DTC.


Jim

A couple of thoughts.

The problem may be a bad brake switch, located above the gas pedal. This may be a cheap fix (~$15). Since it is a systematically weak part across many Mercedes models, you won't be wasting your money.

If the brake switch isn't the problem, then it's beginning to look more like a bad ETA (electronic throttle actuator). I agree with J. M. van Swaay and you'll need to fix this part. I rebuilt mine - the wiring insulation turned to dust on my workbench.

You'd have three options available to you:
1. replace the ETA with a new unit (~$1400)
2. have the unit rebuilt (~$400, from Beckmann Technologies?)
3. replace the wiring yourself

__________________
95 E320 Cabriolet, 169K

Unlikely that brake switch is the problem--Idle speed control fault is not affected by brake switch. Idle speed control fault is almost always associated with bad throttle actuator. Inop cruise control can be caused by either bad TA or bad brake switch. (because you have ISC fault AND inop cruise--you probably have bad TA)

If you can do without the car long enough for round trip shipping, I'm pretty sure 4mercedes and/or Beckmann can bench test your unit before you buy a reman.

By the way, I have had cases where clearing DM (pin 3) codes require that you go through the clear procedure, then turn ignition off, wait a half a minute or so, then turn igniton back on and check again. You should then get no blinks. You will not get a single blink until you have completed several drive cycles with no faults.

Hope this helps.

J. M. van Swaay

__________________
1994 E320 Wagon, 230,000 miles
1995 E320 Sedan, 106,000 miles
1994 E500 Sedan, 79,000 miles

Thank you all of the information helps.

I read some bad reviews about the 4mercedes.com company on Jim F's web site http://www.k6jrf.com/MB_asr.html Has anyone delat with this company lately?

Is there a way to diagnose which of the pin 14 code 2 variables, i.e. "EA/CC/ISC control module (N4/1) or Safety contact switch (M16/1s1) or Stop lamp switch or Cruise control switch or Actual value potentiometer or Starter lock-out/back-up lamp switch or engine speed signal or vehicle speed signal or closed throttle position switch or safety relay in EA/CC/ISC control module" may be causing the problem without buying parts?

Also, is there a way to figure out what part of the ETA is bad without sending it to one of the reman companies? It could be the wiring and/or the potentiometer or the circuit board. I am guessing the reman place will simply rewire and I would get back a worn potentiometer.

Jim

Yes, there are test procedures to further diagnose pin 14 code 2. These procedures are not described on the service CD, they might be described in the WIS but I don't have WIS so I'm not sure. If you subscribe to AllData, the information is available there.

I went through some of these procedures when I was working this same problem. The test procedures are pretty involved and require some special connectors (or a lot of fiddling with jumper wires...) that allow you to tap into the electrical harnesses/modules associated with the TA. The information that AllData provides describes the tests but does not include much background explanation. Bottom line: Not a very DIY friendly process.

J. M. van Swaay

__________________
1994 E320 Wagon, 230,000 miles
1995 E320 Sedan, 106,000 miles
1994 E500 Sedan, 79,000 miles

One more thing, I would recommend Beckmann over 4mercedes.

J. M. van Swaay

__________________
1994 E320 Wagon, 230,000 miles
1995 E320 Sedan, 106,000 miles
1994 E500 Sedan, 79,000 miles

Could someone help me? I made a code reader for my 300e and now a friend in another state wants one for his car, but its a 38 pin connector. Obviously normal banana plugs are too big. Could I just solder some 12 gauge copper wire to my reader wires? Is 12 gauge too big? Should I use 14 gauge? I'd appreciate anyone with a 38 pin connector to check this for me. Comments appreciated. barbershop@mchsi.com

hey y'all newish to here. i have read multiple threads from here with some great help and guidance. i have a 94 e320 3.2l. i recently changed the plugs wires coils and maf due to a bad idle/misfire. maf seemed to help the misfire/idle. my car still wont go passed 3k rpms i have the code reader and have read and deleted the codes a few days ago with no luck of anything changing. when i first got the car it ran flawlessly. now it wont go passed 3k in drive. in park/neutral it revs perfectly but has no get up to her anymore. i have a o2 sensor on the way. broken vac line im gonna fix tomorrow. after replacing maf today the cat was making a rattling/knocking sound. cat has been replaced and is barely a month old. could it be a bad cat? plugged fuel filter? bad fuel regulator? renaissance valve? throttle body? (have a used one out of 95) can anyone point me in the right direction? any help is greatly appreciated!!!

Robert, if you don't know when the fuel filter was replaced last, replace it.

If you are unfamiliar the fuel filter is under the car in front of, and slightly inboard, of the right rear tire. A black cover protects the fuel filter and fuel pumps from road debris, and is secured by 10mm fasteners. Temporarily clamp the rubber fuel line while changing the filter, or you will have gas draining from the tank.

__________________
Fred Hoelzle

Where did you buy the cat? I had the same problem my cat also was a month old.