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1995 Mercedes S420, 1995 SL320, 2000 Land Rover Discovery II, 1985 Lotus Turbo Esprit
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Discussion Starter #1
Hi everyone -- This is something that's been driving me nuts for the better part of a year now. It's just enough of a nuisance that I want it resolved, but not enough that really impacts the functionality of the car.

When I turn the car on from cold -- actually cold, as in sitting all night in sub-60-degree weather -- I get the ASR light. I let the car run for maybe ten seconds, turn it off and then turn it back on again and it's gone for good (until the next morning of course). No issues after that as long as the car remains somewhat warm over the course of the day.

All the major wiring work has been done on my car, including a rebuilt ETA that's only about three years old.

This really seems to be temperature-dependent, as it rarely happened during the summer, but now that the weather is getting colder it's every morning. Any ideas?
 

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1994 S500 Coupe
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581 Posts
Goes without saying, the code in the ASR module would be of interest.

May not have anything to do with the wiring or ETA, but could be a sensor that the ASR module uses. Could even be the computer itself someway.
 

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1994 S600 Coupe, 1995 S600 Coupe
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Try removing and reseating the ASR and ETA modules. Make sure they are fully seated, using a rubber mallet if you need to. I had a similar issue, and that cured it for me.

Jon
 

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94 - S500 Cpe
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361 Posts
All the major wiring work has been done on my car, including a rebuilt ETA that's only about three years old.
Had the same problem apx three (3) years later and it was the Neutral Safety Switch. As recommended, you should dump the DTCs when the ASR lamp is lighted . . .

Direct link here to the ASR page; scroll down to section: Update: ASR Revisited (10/19/07)".
 

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1995 Mercedes S420, 1995 SL320, 2000 Land Rover Discovery II, 1985 Lotus Turbo Esprit
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Discussion Starter #5
Thanks guys.

Jim -- I just had a look; you wrote that your issue didn't happen when the car was cold (only warm). Mine is the exact inverse. Do you think it could still be the NSS? Otherwise the symptoms are identical, including the 'chasing idle' if I allow the car to continue to run with the ASR fault active.
 

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S 350 Turbo diesel,Porsche 944 (83,84,85 and 86),Toyota Supra MA61 85,Opel GT 71
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157 Posts
Is your battery good?If it is not so good it can trigger different types of faults when you start the car,because it has not enough capacity to give power to all components,and voltage drops and that triggers the fault.
 

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1995 Mercedes S420, 1995 SL320, 2000 Land Rover Discovery II, 1985 Lotus Turbo Esprit
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Discussion Starter #8
Is your battery good?If it is not so good it can trigger different types of faults when you start the car,because it has not enough capacity to give power to all components,and voltage drops and that triggers the fault.
Ah. Very interesting you said that.

My battery is in fact less than a year old -- HOWEVER, this all began about a year ago when I was having alternator/battery issues. My alternator voltage regulator went bad and it drained my battery a few times. I had intermittent starting issues for about a week until I had the repair performed, and the ASR light on startup was part of the problem. New voltage regulator and new battery were installed. Battery is a proper-sized Bosch.

The problem has been with me intermittently ever since. As I mentioned, much worse in the cold weather.

Could this still be related to a voltage issue?
 

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Is your battery good?If it is not so good it can trigger different types of faults when you start the car,because it has not enough capacity to give power to all components,and voltage drops and that triggers the fault.
Good point . . . had the same sort of problems a few years ago due to a failing battery: you can check the battery at rest . . . should show 12.25 V min . . . if below you should investigate.

My battery is in fact less than a year old -- HOWEVER, this all began about a year ago when I was having alternator/battery issues. My alternator voltage regulator went bad and it drained my battery a few times. I had intermittent starting issues for about a week until I had the repair performed, and the ASR light on startup was part of the problem. New voltage regulator and new battery were installed. Battery is a proper-sized Bosch.

The problem has been with me intermittently ever since. As I mentioned, much worse in the cold weather. Could this still be related to a voltage issue?
IMO, it could be but test the battery at rest (after it sits awhile) to see the terminal voltage.
Also when you go to start the engine, watch CAREFULLY all of the LAMPS in the IC . . they shouldn't DIM to almost OFF . . that shows a weak battery which as Zloca indicated, could be the cause of setting "phantom" codes. Had this happen to me due to a weak battery.
 

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1995 Mercedes S420, 1995 SL320, 2000 Land Rover Discovery II, 1985 Lotus Turbo Esprit
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Discussion Starter #10
Any advice on a code reader for the pre-ODBII cars? I've seen diagnostic laptops available but I don't want to spend $500. I also don't want to have to drive to my mechanic every time I need the computer checked.
 

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Sure, you can BUY one complete with "manual" . . here
-- or --
You can build one yourself here

Of the two, I recommend the 1st choice since you get a code manual so you can look up the "flashes" to see what they mean . . .

I've been looking and evaluating some of the new "OBDx" code readers but NONE that I've found will do the early OBD1 MBs.
 

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600 coupe, one of the very first built
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I've been looking and evaluating some of the new "OBDx" code readers but NONE that I've found will do the early OBD1 MBs.
This is correct. Only some professional, old-school scanners (Snap-On, etc) and the MB proprietary HHTWin (part of the Star Xentry suite) will read the codes that the older generation Benzes flag.
Has been discussed many times on this forum. Nobody is making new scanners for cars built with technology from the 80s and 90s.
 

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This is correct. Only some professional, old-school scanners (Snap-On, etc) and the MB proprietary HHTWin (part of the Star Xentry suite) will read the codes that the older generation Benzes flag.
The best of the 'early' scanners is the AST Retreiver w/ the 5704E cartridge - - does all MBs from the late 80's to 2002's MBs including live data.

My web page here shows the Trisco Palm Scanner . . which is quite good. If you can find one on the used market, I'd buy it.
 

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600 coupe, one of the very first built
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Trisco Palm Scanner . . which is quite good. If you can find one on the used market, I'd buy it.
FWIW, one of the most active members here shared this info a couple of weeks ago:

I have a Trisco CS-3000 system which is a large handheld device, but I find it much easier and faster to use the STAR system as it can present a whole lot of live data at once vs a small LCD display on the Trisco. It took me over a year to find a Trisco system; they are that rare. I thought I'd like it more than I do, and that it would be more convenient to take on trips, but that's not the case.
His recommendation, together with that of many other is to invest in a SDS. The thread covering this discussion is this one:
 

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Any advice on a code reader for the pre-ODBII cars? I've seen diagnostic laptops available but I don't want to spend $500. I also don't want to have to drive to my mechanic every time I need the computer checked.
As is the problem w/ this and many other forums . . NOBODY READS . . they are quick to POST a reply but have not read the previous posts and UNDERSTOOD what Thom_7, thread starter wants!!

As you now read, he (in post # 10) doesn't want to spend a lot of $$$ to read OBD1 codes. If you read it, that would have been clear!

So Time Capsule's post of a Trisco 3000 Scanner does not fill Thom's request. That scanner is one of Trisco's HIGH END scanners intended for large commercial shops. And it wasn't that good, as I am familiar with it. It was also EXTREMELY expensive to boot!

For Thom, a simple scanner that plugs into the Diagnostic Connector will do the job.

If one were to come across the Palm Scanner it's a great scanner for OBD1 MBs. It makes it much easier for one who isn't familiar with reading stored DTCs. I haven't seen an ad for one in many years! Price is typically $200 on the used market. I have one it's great for the early MBs w/ OBD1 . . .
 
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