Thanks Jim, Great information. I'll try to get a security torx tool.

UPDATE: . . . four (4) years later . . .

My ASR started acting up again, intermittantly, about 6 months ago. The symptoms were a little different than before . . .

It turned out to be the "S16/3", Starter-Lockout Backup Lamp Switch". . . also called the "Neutral Safety Switch".

Details in MENU#24 at the bottom of the page. . . interesting reading . .

Hi,
I have a 1997 s420 and I have an asr light when I start the car. It does not matter if it is cold or hot. I used a CEN TECH scanner to pull code. It comes up with P1580 which is throttle actuator otherwise known as throttle body. It does not tell me that it is bad. It simply says throttle actuator. Could there be anything to check before I replace this unit. It is quite expensive ($1500) and I can't return it. Would a mercedes benz dealer agree to check unit if I took it to them after I take it out of the car. I already checked the unit's electrical wires and they seem to be fine. I took the unit off the engine and still had it plugged into th harness. I sat the unit by the winshield wippers where I can still see it while I seat behind the wheel. I turned the key into position 2 but not crancking the motor. The butterfly inside the throttle body opens wide and stays like that. is that normal? Has anyone tried this before? What should I expect from a working ETA?
Any help is appreciated.

Menu#24 shows some sources that will rebuild/refurb your ETA. I know Beckmann can test it for a reasonable price. There are probably others that will also.

I don't think that a MB dealer can actually 'test' one other than installing into an engine. . . and they wouldn't do that just to test your ETA.

The ASR light started coming on on my S500 pretty regularly. I'd turn the car off and restart and it would go away. Then it started to get worse. I had my mechanic do the major service (it was do anyway) in may and (knock on wood) it hasn't happened again.

Go figure...:devilish: