Need Help!!!

[_BenzW124]

Hey guys

I am looking for your help and advice for the codes below on my 1994 E420 with ASR. I appreciate if you would please help point me to the right direction and the possible causes why I'm getting these codes as a beginner!

I retrieved these with the blink code reader:

Pin 4:
code 1

Pin 6:
code 3

Pin 7:
code 1

Pin 8:
code 6

Pin 14:
light stays on constantly and no blink

Pin 16:
light stays on and 1 blink

Pin 17:
code 1

Pin 19:
code 7

Pin 30:
codes: 3, 4, 8, 9

 

[Jlaa]

Hey guys

I am looking for your help and advice for the codes below on my 1994 E420 with ASR. I appreciate if you would please help point me to the right direction and the possible causes why I'm getting these codes as a beginner!

I retrieved these with the blink code reader:

Pin 4:
code 1

Pin 6:
code 3

Pin 7:
code 1

Pin 8:
code 6

Pin 14:
light stays on constantly and no blink

Pin 16:
light stays on and 1 blink

Pin 17:
code 1

Pin 19:
code 7

Pin 30:
codes: 3, 4, 8, 9

Hi! How fresh are these codes? Meaning, how long has it been since you last reset everything and which codes are freshly set, and which codes are stale?

You may also wish to consult the M119 DTC list manual, which I have attached below, which was fetched from @gsxr's excellent w124performance.com website (I site suck everythere there on a regular basis so now I work off local copies):

 

[_BenzW124]

Hi! How fresh are these codes? Meaning, how long has it been since you last reset everything and which codes are freshly set, and which codes are stale?

I have no clue. This is the first time I'm reading the codes. The check engine light came on couple months ago and went off by itself.


You may also wish to consult the M119 DTC list manual, which I have attached below, which was fetched from @gsxr's excellent w124performance.com website (I site suck everythere there on a regular basis so now I work off local copies):

I did look at this DTC list manual but don't know where to start digging more! Like code 7 from Pin# 19 says "Ignition system defective: Test distributor ignition system."
I inspected my distributor caps,rotors, and spark plugs and they were all good. Do you know where section 5.2 would be referring to under this code's remedy???

 

[gsxr]

Is the CEL on, or is the engine not running properly? If so, what are the symptoms/problems?

There should be nothing connected to pin #14 for North American W124/M119 vehicles. Ignore that socket.

Those may be old codes, clear everything, and see which (if any) reappear quickly, i.e. after a few days of driving, or less.

 

[_BenzW124]

Is the CEL on, or is the engine not running properly? If so, what are the symptoms/problems?

There should be nothing connected to pin #14 for North American W124/M119 vehicles. Ignore that socket.

Those may be old codes, clear everything, and see which (if any) reappear quickly, i.e. after a few days of driving, or less.

The CEL is currently off, but it came on yesterday and went off. Engine runs a bit rough after cold starts and idle drops too quick (feels as if one or two cylinders are not firing.) Runs rich and has exhaust gasoline smell. The ABS and ASR lights are both on the entire time, assuming its related to the code for the right front speed sensor. I also have an issue with the A/C working intermittently. Sometimes The compressor engages and sometimes it doesn't. After restarting the car a couple of times it engages and is ice cold!

I will clear the codes and see which ones come back and report back.

 

[sheward]

Has the wiring harness been replaced?

drew

 

[_BenzW124]

I think so, according to the date code below.

 

[gsxr]

The CEL is currently off, but it came on yesterday and went off. Engine runs a bit rough after cold starts and idle drops too quick (feels as if one or two cylinders are not firing.) Runs rich and has exhaust gasoline smell. The ABS and ASR lights are both on the entire time, assuming its related to the code for the right front speed sensor. I also have an issue with the A/C working intermittently. Sometimes The compressor engages and sometimes it doesn't. After restarting the car a couple of times it engages and is ice cold!

I will clear the codes and see which ones come back and report back.

You appear to have multiple problems. Did all of these occur overnight, or did they occur separately over time and you are just now diagnosing?

ABS+ASR lights on all the time seems to indicate limp mode. Is throttle pedal travel abnormal? Or, do the ABS+ASR lights not turn on until you
start driving? This may be related to the speed sensor.

It also sounds like you have ignition issues. How old are the caps, rotors, insulators, wires, plugs, and coils? Misfiring will cause the abnormal exhaust odor and rough running. But, a rich condition may also be caused by a faulty MAF or O2 sensor.

The AC compressor engagement is related to code 6 on pin 8, could be a bad belt or tensioner, or bad speed sensor on the compressor.

Need lots more data to diagnose further... the fault codes only point you in the right direction. And, they are useless for diagnosing secondary ignition problems.

 

[_BenzW124]

You appear to have multiple problems. Did all of these occur overnight, or did they occur separately over time and you are just now diagnosing?

ABS+ASR lights on all the time seems to indicate limp mode. Is throttle pedal travel abnormal? Or, do the ABS+ASR lights not turn on until you
start driving? This may be related to the speed sensor.

It also sounds like you have ignition issues. How old are the caps, rotors, insulators, wires, plugs, and coils? Misfiring will cause the abnormal exhaust odor and rough running. But, a rich condition may also be caused by a faulty MAF or O2 sensor.

The AC compressor engagement is related to code 6 on pin 8, could be a bad belt or tensioner, or bad speed sensor on the compressor.

Need lots more data to diagnose further... the fault codes only point you in the right direction. And, they are useless for diagnosing secondary ignition problems.

No, they occurred separately over time. The throttle response seems to be ok. Anytime I start the car, the ABS+ASR lights come on instantly. But I took it to a MB specialist to check for possible vaccum leaks that might be causing the cold start idle issue, and they told me there's no vaccum leaks and my throttle is not engaging at all, and need a throttle body! I took a look at the date tag on it and it is dated 07M08. Would this cold start issue be the speed sensor that cause limp mode?

I bought the car last summer, I don't know how old the ignition components are. I checked the spark plugs, caps and rotors all look good and close to new.

Wouldn't a faulty MAF or O2 sensor always throw a CEL? I changed the MAF sensor last year, but not the O2 sensor. Car has around 110,000 miles and the O2 sensor is probably the original one.
I changed the MAF sensor due to throwing a code and running rough when car was warmed up. The culprit of that was a vaccum leak I found that goes from the EZL to the intake manifold. After fixing the vaccum leak, I never got a code for MAF sensor.


**Update on codes**
After clearing all the codes, the only code that came back right away is code 3 on pin 6. In fact, the ABS+ASR lights came on instantly again after starting without the car moving. I did not even have to drive the car to get the ABS+ASR lights to come on. Would this be a hard code?

 

[gsxr]

Anytime I start the car, the ABS+ASR lights come on instantly.

It sounds like the ABS/ASR computer may be faulty, OR not receiving power. You probably have non-functional ABS and ASR, you could test this on a dirt road, or wet/dirty pavement, at low speeds. This issue is unlikely to be from the speed sensor, unless the sensor is dead or the wire is broken. You can unplug the sensor, attach a volt meter, and spin the front wheel... should measure AC (?) voltage that increases as the wheel turns faster.

The throttle response seems to be ok. ... But I took it to a MB specialist to check for possible vaccum leaks that might be causing the cold start idle issue, and they told me there's no vaccum leaks and my throttle is not engaging at all, and need a throttle body! I took a look at the date tag on it and it is dated 07M08. Would this cold start issue be the speed sensor that cause limp mode?

If throttle response is normal, you don't have limp mode. In limp mode, the first half the throttle pedal travel does nothing. My guess is, the "specialist" looked down the throttle body with the key on (or engine running) and moved the linkage by hand, which WILL trigger limp mode, and the throttle would not move (or "engage"). Restarting the engine resets limp mode. This has nothing to do with the wheel speed sensor fault.

I bought the car last summer, I don't know how old the ignition components are. I checked the spark plugs, caps and rotors all look good and close to new.

Caps, rotors, and insulators can look ok but still cause problems. However, further diagnostics would be wise before shelling out $500+ for all new components. And, usually this causes misfiring under load, or 10-20 minutes after a cold start... not usually at cold start, and then runs ok after warmup.

Wouldn't a faulty MAF or O2 sensor always throw a CEL? I changed the MAF sensor last year, but not the O2 sensor. Car has around 110,000 miles and the O2 sensor is probably the original one. I changed the MAF sensor due to throwing a code and running rough when car was warmed up. The culprit of that was a vaccum leak I found that goes from the EZL to the intake manifold. After fixing the vaccum leak, I never got a code for MAF sensor.

The MAF or O2 sensor would have to be completely dead to trigger a CEL. They can be reading incorrectly and not cause any fault codes, this is where live data is useful for diagnosis. The O2 sensor generally doesn't cause major running problems, and never at cold start because the engine is still in open loop at cold start.

*Update on codes**
After clearing all the codes, the only code that came back right away is code 3 on pin 6. In fact, the ABS+ASR lights came on instantly again after starting without the car moving. I did not even have to drive the car to get the ABS+ASR lights to come on. Would this be a hard code?

Yep, that's a definite fault you need to diagnose and fix. Also check the 10A blade fuses in the BM/GM module, under the CAN box cover. And test the wheel sensor as described above. Compare to the readings from the opposite side front wheel.

 

[_BenzW124]

What's the best and accurate way to test/diagnose ignition components?

 

[gsxr]

What's the best and accurate way to test/diagnose ignition components?

It's primarily trial and error, or swapping spare components on, or swapping left to right, to see if the problem follows any particular component. This is usually when you are dealing with a persistent misfire that's easily replicated.

If you have live data available from a digital scanner, that will show ignition voltages on each cylinder, which can help pinpoint which cylinders are at fault if you can view the data while the misfire occurs.

 

[_BenzW124]

Last time I checked, Bremi distributor caps and rotors are installed on my car with Bosch wires. Is Bremi good? I could not find any posts that anyone had problems with them.

 

[gsxr]

Bremi is acceptable, but generally not preferred because they were never the OEM for any M119 electrical or ignition components. I don't think they are OEM for any Mercedes parts. Bosch, Beru, and Doduco were the OEM's for M119 ignition components. Several people have had problems with defective Bosch caps out of the box, so it's a real crapshoot these days. Counterfeit Bosch parts from non-authorised vendors just makes the problem worse.

 

[_BenzW124]

Today I was curious to look into possible codes on my car, and upon checking I found on pin#8 code 7 is present. I have no CEL. How would this not show a CEL on the dash?

The dtc manual indicates the "Poly-V-belt slips"! I checked my belt and tension is all good. Do you know where I can start looking into?

Side note:
The A/C compressor is still working intermittently! From my initial post I had code 6 on pin8. Would the new code be related to my A/C not working right? I know they both have a possible cause of the poly-v-belt being the culprit. Let me know if any of you have had the same problem. Thank you in advance!

 

[gsxr]

Today I was curious to look into possible codes on my car, and upon checking I found on pin#8 code 7 is present. I have no CEL. How would this not show a CEL on the dash?

The CEL only displays emissions-related faults. The DM (Diagnostic Module, pin 19) monitors all the powertrain computers and when it sees something it doesn't like, it triggers the CEL. The DM + CEL only exist on USA/Canada cars, the rest of the world don't have this.

So anyway. A slipping belt or AC compressor speed issue won't affect emissions, so the DM doesn't care, and there's no CEL.

The dtc manual indicates the "Poly-V-belt slips"! I checked my belt and tension is all good. Do you know where I can start looking into?

Side note:
The A/C compressor is still working intermittently! From my initial post I had code 6 on pin8. Would the new code be related to my A/C not working right? I know they both have a possible cause of the poly-v-belt being the culprit. Let me know if any of you have had the same problem. Thank you in advance!

Both code #6 and #7 on pin #8 (Basic/General Module) means that the AC compressor speed is not matching engine speed, and it assumes the belt must be slipping, OR the belt is broken / compressor jammed if the speed reading is zero. The BM/GM will then shut off the AC until you re-start the engine. If you are certain the belt isn't the problem, you'll need more diagnostics on the AC. Could be the speed sensor on the compressor, or a wiring issue.

 

[_BenzW124]

Forgot to mention,
when my car is idling looking more closely I do see some play of the belt tensioner kind of moving left to right a tiny bit. Is this normal??? Would this be causing the belt slippage? The belt itself is in like new condition and is on there pretty good. Thanks @gsxr

 

[gsxr]

The tensioner should have no play. You could release tension and verify the pulley bearing isn't bad, but the tension is applied by the spring, and movement shouldn't cause low tension.

 

[gerryvz]

The CEL only displays emissions-related faults. The DM (Diagnostic Module, pin 19) monitors all the powertrain computers and when it sees something it doesn't like, it triggers the CEL. The DM + CEL only exist on USA/Canada cars, the rest of the world don't have this.

So anyway. A slipping belt or AC compressor speed issue won't affect emissions, so the DM doesn't care, and there's no CEL.




Both code #6 and #7 on pin #8 (Basic/General Module) means that the AC compressor speed is not matching engine speed, and it assumes the belt must be slipping, OR the belt is broken / compressor jammed if the speed reading is zero. The BM/GM will then shut off the AC until you re-start the engine. If you are certain the belt isn't the problem, you'll need more diagnostics on the AC. Could be the speed sensor on the compressor, or a wiring issue.

View attachment 137133

I had these same exact codes.

It is most likely going to be either the clutch is fried, or the RPM sensor on the rear of the compressor is faulty.

Both can be replaced (particularly if the compressor is removed -- 4 bolts). The clutch is available as a separate part, but it is almost as expensive as an entire new compressor !! The clutch can be replaced with the compressor on the car, if indeed it is the problem.

The RPM sensor is not available from MB as a separate part, but is easily replaced with the compressor removed from the car.

 

[gerryvz]

Forgot to mention,
when my car is idling looking more closely I do see some play of the belt tensioner kind of moving left to right a tiny bit. Is this normal??? Would this be causing the belt slippage? The belt itself is in like new condition and is on there pretty good. Thanks @gsxr
View attachment 137134

The late model belt tensioners are not really all that known for going bad. That's not to say that they don't go bad. But if there is slight movement by hand, and yet the tensioner retains its spring action (and provides appropriate resistance), I would look elsewhere as to the cause of the A/C compressor codes. In my case, when I got the same codes, it was the compressor (clutch), not the belt/tensioner, that was the problem.

 

[_BenzW124]

Update,
I got around and changed my right side ABS speed sensor today. Once I turned the car on, the ABS and ASR lights are still constantly on.
I drove the car for about 8 miles.
Now my question from you guys is, do I have to drive the car for a certain amount of miles so the ABS and ASR lights go off? Or do I need to reset the ABS system? Your help is very appreciated! Thank you

 

[gsxr]

If the sensor was the only fault, the lights should have gone out immediately. There's nothing to reset.

Can you check for fault codes at the ABS/ASR module (socket 6 of the diagnostic port)? If codes exist, clear them, drive the car, and re-check. Codes which keep returning need to be fixed.

Have you checked all fuses at the BM/GM module? See post #10 above.

 

[_BenzW124]

If the sensor was the only fault, the lights should have gone out immediately. There's nothing to reset.

Can you check for fault codes at the ABS/ASR module (socket 6 of the diagnostic port)? If codes exist, clear them, drive the car, and re-check. Codes which keep returning need to be fixed.

Have you checked all fuses at the BM/GM module? See post #10 above.

Yes I checked the codes on socket 6 and I got code 3 again. I reset it and as soon as I turn the ignition on this code comes back right away!

I've checked all the fuses at the BM/GM module and they're all good.

I went ahead and did the test as you recommended, and I found something that could be the culprit to my ABS+ASR lights being always on and code 3 on socket 6.

When I checked the voltage at the sensor end on the right side I got zero reading when spinning the wheel! I also went ahead and checked voltage of the wiring coming from the car and there was no voltage at all!

However, when I checked the voltage at the sensor on the left side I got readings while spinning the wheel. The voltage increased as i turned the wheel faster. Then I checked the voltage of the wiring that comes from the car of about 4.6 volts!

Where should I from here?!

 

[gsxr]

Might be a wiring issue between the module and the sensor. You'll need to get a pinout of the module and trace in between. In the meantime pull the module and make sure all pins are clean and straight, and all sockets are clean and undamaged. I assume you've already tried removing & re-seating the module.

 

[_BenzW124]

Might be a wiring issue between the module and the sensor. You'll need to get a pinout of the module and trace in between. In the meantime pull the module and make sure all pins are clean and straight, and all sockets are clean and undamaged. I assume you've already tried removing & re-seating the module.

Yes, I've already removed and re-seated the module couple times, but no luck. Everything on the module seems to be in its place.

I have no knowledge of the wiring on the car and would have to take it to a shop to have them sort it out.

Wouldn't the driver's side wire from car also not get voltage due to this? Or do each wire have separate source of power?

 

[gsxr]

All four wires (2 for left sensor, 2 for right) go to separate pins at the module. Looks like pins 13 and 34 for the right front sensor. If the wiring is good, the module itself could be faulty.

Pinout diagram here:

http://124performance.com/docs/mb/M119/124_ASR_pinouts.pdf

 

[_BenzW124]

All four wires (2 for left sensor, 2 for right) go to separate pins at the module. Looks like pins 13 and 34 for the right front sensor. If the wiring is good, the module itself could be faulty.

Pinout diagram here:

http://124performance.com/docs/mb/M119/124_ASR_pinouts.pdf

@gsxr Thank you for the pinout!
How would I check if pins 13 and 34 are getting power?? Is it possible to do it with a voltmeter?!

 

[gsxr]

@gsxr Thank you for the pinout!
How would I check if pins 13 and 34 are getting power?? Is it possible to do it with a voltmeter?!

I would use an ohm meter between the socket (with module removed) and the sensor connector. If that checks out OK, for both wires, also checking the driver side to confirm... the module is probably bad. Modules are cheap because they are such rare failures.

Note there are 2 separate connector blocks with similar numbers, make sure to measure at the correct one.

 

[_BenzW124]

UPDATE

So I used an ohmmeter and got readings between the sockets number 13 and 34 for the right VSS. I believe it was 14 or 16 ohms, somewhere around there. So that checked out.
As @gsxr said, I suspected the module could be bad and ordered a good used one that works. Today I installed the one that came in and still no change!!! As soon as I start the car ASR+ABS are lit. I checked the codes on the ASR module and still getting code 3, tried erasing and comes back right away. Hard code!

Upon closer inspection of the sockets, socket 13 seems to be seating lower than all other sockets on the lower block. In fact, all other sockets look to be seated higher than socket 13, which you mentioned is one of the sockets related to the right VSS. I have attached a photo down below.

I don’t know if thats what’s causing my ABS+ ASR to illuminate. I checked if the socket(13) and the pin on the module would make contact, and they are, since the pin is long enough to get down in there. Is there anyway to remove the whole lower block and push socket 13 up a little to see if it makes any difference? Your help is really appreciated.

 

[gsxr]

I think you may have figured it out. The metal spring connector inside socket 13 does appear to be pushed out of place, which would cause the fault code & warning lights.

To access the underside, you must dismantle the CAN box. Not difficult, just tedious:

 

[_BenzW124]

Also forgot to mention,
Sometimes when applying the brakes the exterior lamp failure light on the dash comes on. I have checked all the exterior lamps and all are working including the license plate lamps.

By any chance does this have anything to do with my ABS+ASR situation???

 

[Jlaa]

Also forgot to mention,
Sometimes when applying the brakes the exterior lamp failure light on the dash comes on. I have checked all the exterior lamps and all are working including the license plate lamps.

By any chance does this have anything to do with my ABS+ASR situation???

Most likely not. For the lamp failure light, start with checking all the ground connections at all the bulbs and the bus-bar-ground inside the taillamp housings. Also make sure all the correct bulbs are being used. (meaning 21 watters not those US-spec 26 watters). Then move on to the N7 BOW relay under the hood near the brake booster.

 

[_BenzW124]

I think you may have figured it out. The metal spring connector inside socket 13 does appear to be pushed out of place, which would cause the fault code & warning lights.

To access the underside, you must dismantle the CAN box. Not difficult, just tedious:

Ok, so I’m in the process of removing the box right now.


I tried removing the can box but so far unsuccessful. I could not find any posts showing the removal of the box.
Is there anyway you could help out??

I’ve removed the 4 long bolts that hold it down and the two short bolts that are on the side near fender. What else should I loosen? I probably have to remove that 38 pin connector!

 

[_BenzW124]

Do I also have to remove these two bolts here?? How???

 

[_BenzW124]

HOOOOOOOOORAYYYYYYYY

Ok guys,
This is it!!!!!!
I was able to remove the CAN box.
I can’t believe I have fixed it. Look at my dash looks awesome!!!

Once I got the box removed, I pushed socket 13 up to where it needs to sit and put all modules in and started car, being surprised that both ABS+ASR light are gone. I am very thankful for all the help you guys did for me. I wouldn’t have solved this without you guys and this site.
Otherwise I would have taken my car to a Mercedes shop charging me $$$$ for a simple connection problem like this.

Special thanks to @gsxr, @gerryvz and @Jlaa who helped me tackle down this without any prior knowledge about the system myself.

 

[gsxr]

Fantastic! Glad you were able to figure it out. Sorry for the late reply, I was away from the computer this AM and didn't see the posts about the CAN box. It's a bit of a puzzle to locate all the bits needed to get it apart. I wonder how that one single connection worked loose over time? Weird.

 

[French02chris]

Bremi is acceptable, but generally not preferred because they were never the OEM for any M119 electrical or ignition components. I don't think they are OEM for any Mercedes parts. Bosch, Beru, and Doduco were the OEM's for M119 ignition components. Several people have had problems with defective Bosch caps out of the box, so it's a real crapshoot these days. Counterfeit Bosch parts from non-authorised vendors just makes the problem worse.

i know this is from June......but here is my experience with my NEW bremi rotors!!!
First of all, the "NEW" ones look different than the "OLDER" bremi!!! ( and weight a little less!!!! lol )
anyways, I replaced a rotor with a NEW bremi and after a few miles ( 40 or so) on highway ( 70-80 mph), the car started to misfire when I took my exist to go home ( had to drive really slowly)....I replaced my NEW bremi with an older one, and the misfire disappeared ( I switched back and forth about 3 times to confirm).....SO, I ordered another NEW bremi ( maybe i received a defective one?!), put the newer one, and 40 miles later on highway, the car misfired again ( I was driving on the highway , so i made it to a gas station at an exit).....I , then installed back my OLD Bremi ( which i had in my trunk) and the misfire was gone again!!!!!!!!!!
Drove back home ( 100 miles on Highway at 70-80 mph and NO misfires!!! )
So, I returned the Bremi ( FCPeuro) and bought some Bosh instead ( should arrive later this week, I hope)

on the photo, the OLDER Bremi style has writing on it
I weight them 5 times just to make sure....lol

 

[gsxr]

Whoa. You had TWO defective Bremi rotors, new out of the box??!!!

Keep us posted if the new Bosch rotors work better!

 

[gerryvz]

Bremi is crap. Beru or BOSCH only.

 

[French02chris]

Bremi is crap. Beru or BOSCH only.

Yep, i ordered Bosch...should arrive in a couple of days.....

 

[French02chris]

Whoa. You had TWO defective Bremi rotors, new out of the box??!!!

Keep us posted if the new Bosch rotors work better!

Replaced the ignition coils today ( less than 1.5 hours without removing the headlight....that time includes losing and retrieving a 8mm bolt and my 10mm socket!!! LOL )
Spark plugs wires are next ( Friday)

 

[French02chris]

SO....to finish my post :
Replaced both ignition coils with Bosch, ( to go with the new Bosch rotors)
Replaced Spark plug wires......
It has been a few weeks now, and NO more misfire at all ( probably drove a 1000 miles or so since then)..lol