Check engine light - 94 w124 m104 - Techs help!? - PeachParts Mercedes-Benz Forum

skiier3_9 · #1 05-26-2006, 04:34 PM

So - I was reading codes from the 16 pin DM today when I messed something up. With the ignition on/engine off-

I read a code on pin 3 (6 blinks - Idle Speed Control Faulty) then attempted to clear it by holding the sw. down for 8 - 10 seconds. I then tried to read the code again (to make sure it was cleared) and it came back (still 6 blinks, not 1). While it was flashing the code out I turned the ignition off. This must have messed something up because the "Check Engine" light then came on when I started the car. I thought that I must have messed up the memory so I unplugged the battery for a bit and reconnected it. The check engine light went out.

The problem is that if I try to read the codes on pin 3 I get nothing (ignition on/engine off AND ignition on/engine on) - no blinks after holding the switch down for 2 - 4 seconds. Furthermore, when I do this, the "Check Engine" light comes back on.

What did I mess up by turning the igntion off as the car was reading back the code from pin 3?

HELP!!

-- Thank you!!

Arthur Dalton · #2 05-26-2006, 06:28 PM

You sell the code reader on Ebay and you don't know how the codes/pins are programmed ???
My, My.... what do you tell the people who buy the code reader from you ?????????????????????

skiier3_9 · #3 05-29-2006, 11:11 AM

I'm sorry - I don't claim to know everything and I'm certainly less knowledgeable about these cars than you are - but I have never run into this problem before. I would be interested to know how each of the pins are programmed and I have searched the forum here and can't seem to find this information.

skiier3_9 · #4 05-30-2006, 04:00 PM

I think that I've found the cause:

"The permanent fualt memory in the diagnostic module has been eliminated and replaced by a fault memory. As a result, faults in the fault memory are erased if the voltage suply is interrupted.

In addition, after the fault memory is erased or after connecting the battery, the pulse display "1" (no fault) does not appear any longer.

The pulse readout "1" is not output again until the diagnostic module has checked all the components and control chains during the subsequent journey and has not found any fault."

Just one question - how many "journeys" does it take for the diagnostic module to check all the systems/control chains?

EDIT: A "journey" has been accomplished if:
- road speed > 4 km/h
- engine speed > 700/min
- engine switch off for 30 seconds

Still don't know how many journeys are required.

ronald_m · #5 05-30-2006, 04:47 PM

Quote:

Originally Posted by Arthur Dalton

You sell the code reader on Ebay and you don't know how the codes/pins are programmed ???
My, My.... what do you tell the people who buy the code reader from you ?????????????????????

Got owned.Lol.

skiier3_9 · #6 05-30-2006, 05:06 PM

By Mr. Dalton himself....

I would appreciate some help though. I've never had anyone interupt power to the diagnostic module while reading a code before - I didn't realize it would cause such a problem.

Educaid · #7 05-30-2006, 11:17 PM

Either Mr. Dalton knows the answer and is not saying because someone had the audacity to meddle in his area of expertise in which case you can draw your own conclusions or he doesn't know the answer. Either way, his reply was rude and uncalled for. By the way, I bought one of Skiier's devices and it works well.

Motorhead · #8 05-31-2006, 03:51 AM

skiier, I used one of your code readers to find the code and shut off the light and I too could not get the light to go off. I momentarily disconnected the battery and the light now stays off. The early on board diagnostics, in my opinion, are a pain in the a$$!!

qdessa · #9 06-07-2006, 09:03 AM

Where can I find an inclusive list of the codes for a 95 W124 ?

I seem to be able to find bits and pieces but not the entire list.

Arthur Dalton · #10 06-07-2006, 10:23 AM

Quote:

Originally Posted by qdessa

Where can I find an inclusive list of the codes for a 95 W124 ?

I seem to be able to find bits and pieces but not the entire list.

E320 16 PIN DTC Charts inc. pin 8, pin 14

dtf · #11 06-07-2006, 07:50 PM

Mr. Educaid, I'm glad your code reader works well but after following this web site for 4 + years I find Mr. Dalton one of the most generous, knowledgeable and commited members here. Many, many members have used his knowledge to fix problems and we will continue to as long as Arthur is generous enough to share his thougths. Please refrain from quick judgements on members as we are all here for one thing - the love of our MBs.

autozen · #12 06-08-2006, 11:47 AM

Quote:

Originally Posted by Educaid

Either Mr. Dalton knows the answer and is not saying because someone had the audacity to meddle in his area of expertise in which case you can draw your own conclusions or he doesn't know the answer. Either way, his reply was rude and uncalled for. By the way, I bought one of Skiier's devices and it works well.

I think Art was just having a little fun, and besides he's right. A salesman should know his product. One thing that really ticks me off is to go a store and ask a clerk to answer some questions about a product only to have the clerk start reading the info on the box. Hell, I can do that and probably better.

Now for a lesson on code readers. The price of a code reader depends on the amount of engineering that goes into it. Top of the line is from MB. The cost is over $10,000 with a yearly maintenance of a thousand or more. It will do everything including reprogram replaced components to talk to the CANs (Controled Area Networks). It can monitor real time data flow. Next down from that would be an HHT(Hand Held Tester). This is also MB and no longer used by the dealers. It is only good up to around 2002 models. They still pop up for sale ocassionaly on the internet for around $3500. They also can read codes, diagnose, and make modules talk to each other. Moving down the line comes Baum and a couple of other after market scanners that are geared to German cars. These scanners run somewhere between $5000 and $10,000. They do an excellent job pulling codes, resetting codes, and doing diagnostics, but can't make the CAN buses communicate. Dropping down one step further are products like Snap-On that are geared toward American cars. They take a feeble stab at German cars. They are also somewher in the $5000 range. I had a CEL on a late 90s MB. I scanned it with a Snap-ON, and couldn't get any codes. I used a second Snap-On scanner with the same results. I hooked up a Baum and got the three codes I needed to know. WAAAY at the bottom of the list is the $39.95 scanner from Kame-Apart. For that kind of money, you can't expect it to do too much more than your garage door remote. Just because you can't pull any codes, doesn't mean they aren't there. So there you have it folks, and by the way I don't know exactly what all the scanners cost. I was doing ball parks for perspective.Please don't post that the Snap-On unit is $3,984 or something to that affect.Good luck.

Battlecat714 · #13 06-08-2006, 02:47 PM

Quote:

Originally Posted by autozen

I think Art was just having a little fun, and besides he's right. A salesman should know his product. One thing that really ticks me off is to go a store and ask a clerk to answer some questions about a product only to have the clerk start reading the info on the box. Hell, I can do that and probably better.

Now for a lesson on code readers. The price of a code reader depends on the amount of engineering that goes into it. Top of the line is from MB. The cost is over $10,000 with a yearly maintenance of a thousand or more. It will do everything including reprogram replaced components to talk to the CANs (Controled Area Networks). It can monitor real time data flow. Next down from that would be an HHT(Hand Held Tester). This is also MB and no longer used by the dealers. It is only good up to around 2002 models. They still pop up for sale ocassionaly on the internet for around $3500. They also can read codes, diagnose, and make modules talk to each other. Moving down the line comes Baum and a couple of other after market scanners that are geared to German cars. These scanners run somewhere between $5000 and $10,000. They do an excellent job pulling codes, resetting codes, and doing diagnostics, but can't make the CAN buses communicate. Dropping down one step further are products like Snap-On that are geared toward American cars. They take a feeble stab at German cars. They are also somewher in the $5000 range. I had a CEL on a late 90s MB. I scanned it with a Snap-ON, and couldn't get any codes. I used a second Snap-On scanner with the same results. I hooked up a Baum and got the three codes I needed to know. WAAAY at the bottom of the list is the $39.95 scanner from Kame-Apart. For that kind of money, you can't expect it to do too much more than your garage door remote. Just because you can't pull any codes, doesn't mean they aren't there. So there you have it folks, and by the way I don't know exactly what all the scanners cost. I was doing ball parks for perspective.Please don't post that the Snap-On unit is $3,984 or something to that affect.Good luck.

kame-apart...

skiier3_9 · #14 06-08-2006, 08:59 PM

for what its worth - the diagnostic system is reset when power is disconnected in the middle of a code retrieval requiring some number of journeys to re-check all of the systems and make sure there are no faults.

After a week of driving the car everything is behaving normally - one blink from the DM LED.

Arthur Dalton · #15 06-08-2006, 09:25 PM

FWIW.
The DM /N-59 module will NEVER bring up a single flash after the codes have been CLEARED until it goes through ALL emmissions self test.
Once all self test have been activated and PASS , then the DM will show a Single Flash.. and not until.
This is protection from guys clearing bad emmissions codes before DMV testings. It was there for the early Emmisions Inspections .
Unlike the other Diagnostic modules , which will immediately bring up a single flash after code clearing to simply notify the Tech that there are no present codes stored.
Disconnecting power to the DM defaults to code clearing and will result in the same , but that is not the design function of the Self Test of ECU/DM parameters.
Battery power interuption will clear codes, but it also clears management memory, so this is not advisable b/c the engine mangement learning mapping is reset to mean...................