ASR light / limp home / fault code 6 - Page 2 - PeachParts Mercedes-Benz Forum

EricSilver · #16 09-06-2008, 02:33 PM

Could said wet connector have caused an undue battery drain before the car was shut down, with the load from the other always-on systems, i.e. alarm, clock, etc., accounting for further drain, which normally would have no impact?

I just find it odd, and no coincidence, that the ASR issue has not occurred since that sensor was replaced.

As an aside, two years ago, in one brief, freak incident, my ABS pump kept running after the car was shut down. I don’t see how it could have occurred with the car off/no circuit, but it did, which made me wonder whether to same thing could have occurred on the other side of the engine, with the coolant sensor plug.

JimF · #17 09-06-2008, 04:35 PM

There's a 'easy' test that anybody can do to 'check' your battery condition.

It's so simple esp if you have your car garaged. When you go to start it, hesitate a second before engaging the starter to observe the IC lamps. That's your reference level.

Now start the car . . don't take your eyes off the IC; if the lamps dim . . .you've got a battery problem . . . and that will cause phantom problems. You should see almost no decrease in lamp brightness if the battey is "ok".

As I wrote in MENU#33, I recently observed my IC lamps dim badly and sure enough, the battery was 'weak. Details in the article.

Arthur Dalton · #18 09-06-2008, 05:51 PM

<< in one brief, freak incident, my ABS pump kept running after the car was shut down. I don’t see how it could have occurred with the car off/no circuit, but it did, which made me wonder whether to same thing could have occurred on the other side of the engine, with the coolant sensor plug.
>>

No Mystery on that one...the ABS relay contactor was stuck closed and the relay secondary side needs NO KEY b/c those contacts [ 30/87] are ALWAYS HOT, regardless of key position ..it is the relay circuits primary/coil side [85/86] that is KEY cycled....NOT the contactor side.

But on your CLS -S41 circuit, I don't care if you screw the sensor wire to the engine for a ground, it will not be energized until the power is switched/ powered on by KEY/POSITIVE side ...this is according to your schematic, of course......the S41 sensor is a SWITCHED GROUND, completeing the Cluster Indicator lamp...nothing else/more..

EricSilver · #19 09-06-2008, 08:31 PM

JimF:

The IC lights remain steady and bright. (That's a great test, by the way.)

Arthur:

So, is it somehow possible the battery drain was occurring before the car was shut off? (I know it sounds odd, after all, how much power could possibly be drained from a grounded coolant sensor plug?)

Or is there some other component or wiring near/beneath that plug which, if wet, could cause a drain or otherwise trigger an ASR fault? (I vaguely recall someone writing in another ASR thread about a coolant/water leak connection to his problem.)

Edit: If there is such a component, it appears hypersensitive to moisture, considering that humidity changes will impact it.

Arthur Dalton · #20 09-06-2008, 08:56 PM

You may have an ASR circuit connection/component that is sensitive to humid/heat/or other conditions...that is quite common on automotive connections due to the enviorment. But the thought that the S41 sensor electrical circuit has anything to do with ASR circuitry is without any logic.
If the sensor for CL is grounding, the only thing that is in that circuit is the Indicator lamp. And a grounded S41 would result in the indicator being lit if that were the condition. And even then, the draw would certainly not be sufficient to result in a Low Voltage fault to trigger an ASR fault. I do not see a connection between the two independent circuits in any way.

Water leak from sensor getting to an ABS/ASR component ??? I doubt it, but look around that area if you feel that to be possible.
I side with Coincidence ...........

You may want to check all the Brown Ground wire connections under the hood...[ there are several and a simple tightening is all,that is required]...they are commonly sensitive to humid conditions, as are ignition components.

EricSilver · #21 09-06-2008, 09:22 PM

Quote:

Originally Posted by Arthur Dalton

But the thought that the S41 sensor electrical circuit has anything to do with ASR circuitry is without any logic..

Water leak from sensor getting to an ABS/ASR component ???

That much I know. I was speculating on the possible connection between the leak and a battery drain, and the low voltage leading to an ASR fault, as MB Doc described. (I realize the ASR circuitry is in no way connected to the coolant sensor.)

Maybe it is coincidence and can be chalked up to one of those enigmatic things about this car. But it is equally without logic for a fault that was 100%consistent and predictable for the last 7 to 8 moths to suddenly correct itself -- not that I am complaining.

I change my oil tomorrow and will take a look at any wiring in that immediate area, since it is so close to the battery.

Thanks for the good feedback.

Arthur Dalton · #22 09-06-2008, 09:28 PM

< But it is equally without logic for a fault that was 100%consistent and predictable for the last 7 to 8 moths to suddenly correct itself -->

Not at all...Electrical connection do that all the time and is logical. Do not be surprized to see it return.
If I were to suspect a low voltage condition on an124.032 HFM car, my first suspects would be the OVP and/or Voltage regulator, followed up by fuse holder end connections and chassis ground connections............. in that order..........
If it were the V8 versions, I would skip the OVP b/c they do not use one.

EricSilver · #23 09-06-2008, 09:41 PM

Quote:

Originally Posted by Arthur Dalton

Not at all...Electrical connection do that all the time and is logical. Do not be surprized to see it return.

I've been holding my breath for the past three weeks over that thought. Today, given the hurricane weather, it absolutely should have, but I'll just be happy that it didn't.

Arthur Dalton · #24 09-06-2008, 09:48 PM

It's not a big deal , so don't worry about it til it does , if it does..
Intermittants and glitches are very difficult and you may never find the original cause.
If it were me, I would build that led tool and go into the HFM and EA modules every once in a while and see what pops up before any ASR or CE lamp notification..You may just catch it before it clears itself again.
Pending codes are accessible w/tool before they trigger a lamp and the diagnostic modules are fast enough to catch them...but you have to catch them before they clear themselves b/c they do not repeat...
Pin 8 and 14.

EricSilver · #25 09-06-2008, 09:52 PM

Quote:

Originally Posted by Arthur Dalton

If it were me, I would build that led tool and go into the HFM and EA modules every once in a while and see what pops up before any ASR or CE lamp notification..You may just catch it before it clears itself again.
Pending codes are accessible w/tool before they trigger a lamp.

Funny; I have had the schematic for the "Dalton 1000" (my name for the tool after the incident some years back when someone here was selling it on Ebay) in my "My Documents" folder for years, and never built. Perhaps now I will.

Arthur Dalton · #26 09-06-2008, 10:00 PM

Yeah..one of the Kids here took it a step further and sold the idea on ebay ...I made several and sent them out to members for free, but when they started marketing them for sale , I let it go ...you can build it pretty easy for a couple of bucks and it is a cool tool for the DIYer.
The tool advantage is you can get to the Main modules ..whereas the built-in one only gets you Emmissions related codes that activate the CE lamp. ...not much help on the intricate systems, such as ASR, etc....

EricSilver · #27 09-06-2008, 10:01 PM

Just thought of another thing:

I replaced the coolant sensor the day before my annual vehicle inspection, during which the passenger-side front and rear wheels were removed.

I have not removed the rear wheels since changing the tires more than a year ago. Perhaps a dirty wheel speed sensor was inadvertently cleaned when that happened(?)

(as an aside, ny rear pads are starting to wear (front pads are new), and the brake light had been constantly illuminating strongly. Post inspection, the brake light now only illuminates once in a while, and in brief flashes.)

Maybe the connection is with the wheel speed sensor...

Arthur Dalton · #28 09-06-2008, 10:06 PM

Possible..

Another possible is you put air in the tires when you were doing this work...a common ASR code fault is triggered by unequal tire pressure. That shows up on the ECU as it compares all four wheel speed sensor inputs by tire DIAMETER...now , that is LOGICAL......

May even changed the front to rear when putting tires back on......

EricSilver · #29 09-06-2008, 10:20 PM

Quote:

Originally Posted by Arthur Dalton

Possible..

Another possible is you put air in the tires when you were doing this work...a common ASR code fault is triggered by unequal tire pressure. That shows up on the ECU as it compares all four wheel speed sensor inputs by tire DIAMETER...now , that is LOGICAL......

May even changed the front to rear when putting tires back on......

Didn;t add any air, and though I observed the inspector/tech remove the wheels, I never noted the replacement order, but will check that tomorrow -- which will be easy enough since I (should) have same-size ContiTourings in back, and ContiPros up front, however, the ContiPros are newer.

Arthur Dalton · #30 09-06-2008, 10:28 PM

Some Techs claim that even a 1/4" D difference can cause ASR code problems... which is why equal AP is so important...it is the rolling circumference that is the factor to be concerned with for proper WSS inputs..and AP has a direct relation to R/Circ.....
Worth checking into........