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ASR Light
- Thread starter Trae
- Start date
Docs from WIS are attached with the remedy (testing) information. Sounds like it might be related to the ASR charging pump below the master cylinder?? See page 1 of the hydraulic test (note the fault code 21 shown in the left column), also page 5 on the electrics.
Thanks for this information! It will help us get a running start at the problem.
I am just happy that the blink code reader (that you helped me build) was able to pull the code.
Very cool that you got it sorted out. Out of curiosity, did you know much about working on cars before joining this site?
Absolutely not. Dave, Gerry, and others have been my teachers! They and others on this site have armed me with enough information that even the mechanics, that have fixed my cars for the last 15 years, are amazed with the amount of detailed info I can provide. ALL courtesy of Dave and Gerry.
To say that I am thankful to them and this site would be a gross understatement!
To say that I am thankful to them and this site would be a gross understatement!
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That's kind of what I figured. Its quite overwhelming but I am definitely learning a lot as I read through the various threads here! I don't even have a W124 (yet) but it's good to be armed with as much info as possible so I can make an informed decision when it comes time to finally pull the trigger and buy one!
The "Honorable Site Arbitrator" I would say then.
Well, code #21 came back on pin #6 (ASR), has reoccurred three times after clearing, and will not go away. Looks like I'll have to visit my mechanic with all the info that Dave has given me.
At least we'll have a good head start at finding the problem. I'll keep you all posted.
At least we'll have a good head start at finding the problem. I'll keep you all posted.
I have been getting a code 21 on pin 6 for several years now. I too don't know where to go on this. It has no apparent effect on the brakes from what I can tell. I finally unplugged my ASR light bulb because I got tired of looking at it. It wouldn't come on until about 5 minutes after starting the engine. It was like clock work -- I could hear a pump running, then when the pump shut off, the ASR light would come on. I gave up. If you find out what's causing the problem be sure and let us know.
I had just about thrown in the towel and decided I could live with the DTC 21 on pin 6 forever, but if it's just a matter of recharging an accumulator, then I sure would like to know how to do it, if you can find out. No one has been able to help us on this mystery.
Originally posted by emerydc8:
" It wouldn't come on until about 5 minutes after starting the engine. It was like clock work -- I could hear a pump running, then when the pump shut off, the ASR light would come on. I gave up. If you find out what's causing the problem be sure and let us know."
I started experiencing this issue on my 036 2 days ago. I took it to my mechanic who changed the rear light bulbs and the ASR light went off but I still hear the pump. I took it back today. If anyone knows what's causing the issue, I would be very grateful!
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Thankfully, it is bone dry in AZ. I have asked for the codes to be checked but let me where I can get the code reader.
Build the blink code reader, or buy one like this from eBay:
http://www.ebay.com/itm/321033616614
Then discard whatever code translation sheets are included, and use the PDF files attached in the thread linked below:
http://www.500eboard.com/forums/sho...s-(Diagnostic-Trouble-Codes)-on-the-500E-E500
Just ordered the reader on ebay. Thanks!
Here is one for the books.
Since AUG. 2012, the ASR light would come on about 2 minutes after start and stay on.
Pin 6, code 21 said "ASR hydraulic pressure switch- charge."
Then, a month ago, the ABS/ASR pump started to run and vibrate every time I started the engine.
After doing this for about a week, the pump stopped charging (on start up) and the ASR light never illuminated again with NO codes.
Weird. . .may have just needed a charge.
Since AUG. 2012, the ASR light would come on about 2 minutes after start and stay on.
Pin 6, code 21 said "ASR hydraulic pressure switch- charge."
Then, a month ago, the ABS/ASR pump started to run and vibrate every time I started the engine.
After doing this for about a week, the pump stopped charging (on start up) and the ASR light never illuminated again with NO codes.
Weird. . .may have just needed a charge.
what u mean by need charge cause i have aproblemwith asr after driving in sand,every time i start the car i hear the pump then the light come asr,how i can resolve the problem?
I was back in AZ in February and took my car in to have all the faults on the system run. The ASR fault did show up and when they cleared the faults, it did not return though there was a problem with uneven idle. The airflow mass sensor was replaced and since then, the car is running fine without the ASR issues from the past. I'm not sure how the two were connected or if they are connected but I thought I would mention it here.
Well, drove for a year/7000 miles and code #21 on pin 6 with associated ASR light is back and will not go away even though I have cleared the code a half dozen times.
Pin 6, code #21 says "ABS/ASR hydraulic unit, pressure switch (A7/3s1), charge."
Doesn't seem to affect anything as long as I am careful in the rain.
Don't know what to do about this.
Pin 6, code #21 says "ABS/ASR hydraulic unit, pressure switch (A7/3s1), charge."
Doesn't seem to affect anything as long as I am careful in the rain.
Don't know what to do about this.
Jono has not seen the 93' black 500E. So, I have not heard him chime in.
Evidently, from reading on this board, I am not the only one with this recurring ASR light and respective code #21.
Jon said he had driven for years with this code and light.
I guess there will be no need for that ASR defeat switch if this light continues illuminating after driving a few miles.
Evidently, from reading on this board, I am not the only one with this recurring ASR light and respective code #21.
Jon said he had driven for years with this code and light.
I guess there will be no need for that ASR defeat switch if this light continues illuminating after driving a few miles.
Well, it appears that my ASR pump might be failing.
It runs for about 60 sec. after I start the car, vibrating like mad, and then shuts off with an associated ASR light and code 21 on pin 6.
Pin 6, code #21 says "ABS/ASR hydraulic unit, pressure switch (A7/3s1), charge."
My indy has a 93' 400E with ASR in his yard. Do you think switching out the units would solve the problem? Or, should I just keep driving without ASR?
Sometimes it can be a lot of fun, until you get on the petal trying to beat oncoming traffic and find yourself sideways. Then, you have to drive it old school.
It runs for about 60 sec. after I start the car, vibrating like mad, and then shuts off with an associated ASR light and code 21 on pin 6.
Pin 6, code #21 says "ABS/ASR hydraulic unit, pressure switch (A7/3s1), charge."
My indy has a 93' 400E with ASR in his yard. Do you think switching out the units would solve the problem? Or, should I just keep driving without ASR?
Sometimes it can be a lot of fun, until you get on the petal trying to beat oncoming traffic and find yourself sideways. Then, you have to drive it old school.
I seem to be getting this ASR light coming on after a few minutes of driving. it is not in limp mode & the tire(s) are free to spin at will. Car was out of commission for about a year getting a tranny rebuild....yes a year. Weather is off & on up here right now so it has gone back to storage for a few weeks until the frigid weather is not so frigid. I found a this thread and plan to go & try to pull codes later this week and go from there. So grateful for this site to help us all with upkeep of these rare cars.
Interestingly, my high miler went into limp home for the first time in my ownership today. Had to drive it several miles in traffic before I could pull off the freeway. While in LH mode, it wouldn't shift out of (I think) second gear to limit speed. I was eventually able to stop and restart the engine and get home in normal mode.
I pulled code 30 on pin 6 as well several codes from the DM and pin 7. I think many of the codes were caused by my driving the car for a few miles so I cleared everything and will see what comes back.
I pulled code 30 on pin 6 as well several codes from the DM and pin 7. I think many of the codes were caused by my driving the car for a few miles so I cleared everything and will see what comes back.
Glen,
This has happened to me three times in the last four years on my 93'.
I have a 110mi. round trip to work. All three times have been in the heat of the summer.
I have pulled similar codes.
It has not happen in a very long time, and when it does, I simply pull over, restart the engine and complete my trip.
So far, I have not had it happen twice on a trip. That would really get my attention.
I plan on switching out the ASR unit and right rear half shaft to see if I can fix my ASR problem. I am not sure, but there seems to be a link between the ASR and limp home mode.
I have read that ASR uses brakes AND ETA to stop wheel spin in different situations.
Every time I went into limp home mode, It was with the cruise control engaged on a major freeway.
This has happened to me three times in the last four years on my 93'.
I have a 110mi. round trip to work. All three times have been in the heat of the summer.
I have pulled similar codes.
It has not happen in a very long time, and when it does, I simply pull over, restart the engine and complete my trip.
So far, I have not had it happen twice on a trip. That would really get my attention.
I plan on switching out the ASR unit and right rear half shaft to see if I can fix my ASR problem. I am not sure, but there seems to be a link between the ASR and limp home mode.
I have read that ASR uses brakes AND ETA to stop wheel spin in different situations.
Every time I went into limp home mode, It was with the cruise control engaged on a major freeway.
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This is completely unrelated - but it reminded me of an issue I had with my '98 C43. The car would go into limp mode if I hit the kick-down button. Ended up being electrical, and I think it was related to the throttle body. Like our 500Es, the parts on that car were very expensive.
I doubt that helps, but I thought I would throw it out there.
I doubt that helps, but I thought I would throw it out there.
Good luck, Trae. It's hard to believe it's been a year since we discussed this (above). If you figure it out, let us know. As far as stopping performance goes, I haven't been able to see any problems. One thing I did (to ignore it) was replace the rubber bushings that mount that pump to the frame so the vibration transfer isn't nearly as bad when it runs for the first few minutes.
Trae, are you sure you're getting no ASR function when the light is on? IIRC, I believe I tested mine a few times on a dirt road and the ASR actually worked even with the pump not running and the light on.
Trae, are you sure you're getting no ASR function when the light is on? IIRC, I believe I tested mine a few times on a dirt road and the ASR actually worked even with the pump not running and the light on.
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Good point Jon!
Before I go through the work of swapping the units, I'll test it.
We are supposed to get rain in a few days.
I believe that, in certain regimes, the ASR will either use brakes or the ETA to keep the wheels from spinning based on speed of the car.
I assume that if I can get at least one wheel spinning, the ASR will fail the test.
Is this true?
Before I go through the work of swapping the units, I'll test it.
We are supposed to get rain in a few days.
I believe that, in certain regimes, the ASR will either use brakes or the ETA to keep the wheels from spinning based on speed of the car.
I assume that if I can get at least one wheel spinning, the ASR will fail the test.
Is this true?
Here is the latest on the ASR light saga.
The brake fluid was about 1/2 in. below the MIN. mark on the reservoir, so I hypothesized that the ASR pump might not be getting enough fluid thereby causing the pump to vibrate, pressure not within specks, and the ASR light triggered.
So, after already stripping another ASR pump and accumulator from the 93' we were cannibalizing, I decided to simply change the brake fluid to see if that would fix the problem. After the fluid change, we started the engine and waited. Sure enough, the same symptoms occurred. ASR pump vibrated illuminating the light.
It was late in the day, as we had already changed the right rear axle, so I drove home with the light on.
Today, my wife drove the car about 30 miles with the light still illuminated, then I got in the car and noticed that the light did NOT come back on.
After an additional 50 mi., it is still extinguished. Is it too early to celebrate? Will this saga end here?
I believe that the brake fluid needed a little time to cycle through the ASR system and now it likes what it sees.
Stay tuned, if worse case happens, I still have another ASR pump and reservoir I can swap out!
The brake fluid was about 1/2 in. below the MIN. mark on the reservoir, so I hypothesized that the ASR pump might not be getting enough fluid thereby causing the pump to vibrate, pressure not within specks, and the ASR light triggered.
So, after already stripping another ASR pump and accumulator from the 93' we were cannibalizing, I decided to simply change the brake fluid to see if that would fix the problem. After the fluid change, we started the engine and waited. Sure enough, the same symptoms occurred. ASR pump vibrated illuminating the light.
It was late in the day, as we had already changed the right rear axle, so I drove home with the light on.
Today, my wife drove the car about 30 miles with the light still illuminated, then I got in the car and noticed that the light did NOT come back on.
After an additional 50 mi., it is still extinguished. Is it too early to celebrate? Will this saga end here?
I believe that the brake fluid needed a little time to cycle through the ASR system and now it likes what it sees.
Stay tuned, if worse case happens, I still have another ASR pump and reservoir I can swap out!
Trae,
Can you tell if the ASR pump is tapping off the reservoir at a higher standpipe level than the master cylinder? I am going to top off my brake reservoir and see what happens. I hope you fixed your problem.
UPDATE: I added fluid all the way to the max mark. It looks like the ABS pump is getting its supply directly from a master cylinder hard line. There is a small electric motor under the master cylinder and it gets its supply from the lower part of the reservoir via a rubber hose. This whole system has always been somewhat of a mystery to me. I'm not sure what the small electric motor does. I did notice that it too stops operating at the same time the ABS pump up front stops (after a few minutes). That's when the ASR light illuminates.
Can you tell if the ASR pump is tapping off the reservoir at a higher standpipe level than the master cylinder? I am going to top off my brake reservoir and see what happens. I hope you fixed your problem.
UPDATE: I added fluid all the way to the max mark. It looks like the ABS pump is getting its supply directly from a master cylinder hard line. There is a small electric motor under the master cylinder and it gets its supply from the lower part of the reservoir via a rubber hose. This whole system has always been somewhat of a mystery to me. I'm not sure what the small electric motor does. I did notice that it too stops operating at the same time the ABS pump up front stops (after a few minutes). That's when the ASR light illuminates.
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A couple questions to consider & address:
- How long has the brake fluid been low?
- Why is the brake fluid low?
- If the brake fluid is/has been that low, why doesn't/hasn't the low brake fluid warning light illuminate/d?
Regarding the questionable operation/performance behavior of the ASR pump: A high occurrence of fuel pump replacement these days is attributed to constantly driving with low amounts of fuel in the tank (mostly caused by economic constraints). The fuel pump prematurely degrades to failure by constantly working harder at a higher rate trying to pump the necessary fuel (which at the bottom of the tank isn't the best).
A somewhat similar situation could possibly be occurring to the ASR pump if the brake fluid has been running below minimum for a prolonged time.
There should be an ASR system schematic drawing (in the MB workshop manual section?) to help with further understanding of the system.
I spent the last two hours trying to make heads or tails out of the ASR system. It seems that both the ASR pressurizing pump (under master cylinder) and the ASR return/charge pump in the ASR unit should turn on when the car is started and pressurize the accumulator located under the left fender. The charging time is listed as 30-50 seconds.
Trae and I are getting the same code (Pin 6, code #21: "ABS/ASR hydraulic unit, pressure switch (A7/3s1), charge.")
I think in my case the accumulator is not holding a charge after the pumps initially charge it up. I don't know if they are supposed to kick in again if the accumulator pressure drops below a certain level.
The accumulator is $2,440 MSRP and $1,752 at parts.com. For that kind of money, I think I will just leave the ASR light bulb out and pretend that it's like my other E420 without ASR.
One thing I found was helpful to prevent the noise transfer into the frame of the car from the ASR unit is to change the three rubber bushings that mount the unit to the bracket. They are only 36 cents each and it takes about 20 minutes to change them. Since changing the rubber (it was rock hard), I can barely notice the pump running now when I start the car.
Trae and I are getting the same code (Pin 6, code #21: "ABS/ASR hydraulic unit, pressure switch (A7/3s1), charge.")
I think in my case the accumulator is not holding a charge after the pumps initially charge it up. I don't know if they are supposed to kick in again if the accumulator pressure drops below a certain level.
The accumulator is $2,440 MSRP and $1,752 at parts.com. For that kind of money, I think I will just leave the ASR light bulb out and pretend that it's like my other E420 without ASR.
One thing I found was helpful to prevent the noise transfer into the frame of the car from the ASR unit is to change the three rubber bushings that mount the unit to the bracket. They are only 36 cents each and it takes about 20 minutes to change them. Since changing the rubber (it was rock hard), I can barely notice the pump running now when I start the car.
Attachments
DerFuror,
All good questions.
1. I change brake fluid on a yearly basis and check it just about every fill up. The problem is that the fluid level is hard to see
http://www.bing.com/videos/search?q...&mid=B340FE2F06D3A87DA9B9B340FE2F06D3A87DA9B9
when it is changed every year AND they quit making the ATE BLUE that you CAN see.
2. It had been about 1/2in. below minimum for only a short time, and I topped it off with ATE Dot 4 upon discovering this.
3. Even after I topped it off, the ASR light was still illuminated.
4. Never got a "low brake fluid light."
5. Check entire brake system while on lift for leaks and found none.
6. There obviously IS a very slow leak somewhere as I have never had to add fluid to any of my cars between brake fluid changes.
I should have another 500 mi. on the car shortly, then I can determine IF the low fluid had anything to do with the ASR problem.
All good questions.
1. I change brake fluid on a yearly basis and check it just about every fill up. The problem is that the fluid level is hard to see
http://www.bing.com/videos/search?q...&mid=B340FE2F06D3A87DA9B9B340FE2F06D3A87DA9B9
when it is changed every year AND they quit making the ATE BLUE that you CAN see.
2. It had been about 1/2in. below minimum for only a short time, and I topped it off with ATE Dot 4 upon discovering this.
3. Even after I topped it off, the ASR light was still illuminated.
4. Never got a "low brake fluid light."
5. Check entire brake system while on lift for leaks and found none.
6. There obviously IS a very slow leak somewhere as I have never had to add fluid to any of my cars between brake fluid changes.
I should have another 500 mi. on the car shortly, then I can determine IF the low fluid had anything to do with the ASR problem.
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Trae, even $400 is more than I would be willing to shell out just to get the ASR light out. I'm going to test drive it today and see if the ASR still works. I'm pretty sure it does.
Patrick, I do need to find out more about which junk yards have older MB's. I inquired in the past and had no luck. It would be nice to frequent them just to pick and pull some select parts that are selling for astronomical rates, like the ignition module, ASR accumulator and some of the electronics. It would also be nice if the local junk yards had a notifying service (email) that would give a heads up upon the acquisition of specific cars.
Patrick, I do need to find out more about which junk yards have older MB's. I inquired in the past and had no luck. It would be nice to frequent them just to pick and pull some select parts that are selling for astronomical rates, like the ignition module, ASR accumulator and some of the electronics. It would also be nice if the local junk yards had a notifying service (email) that would give a heads up upon the acquisition of specific cars.
