SL/R107: o2 sensor light, always on
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Newbie
Joined: Jun 2006
Posts: 18
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o2 sensor light, always on
i have an 84 380sl, the sensor red light is always on...i guess thats why the previous owner pulled the bulb, several questions, what and how does the sensor do? i have checked the wire going to it, it is not hot or grounded, so i assume it gets warm and then gives a ground, like a temperature sending unit, so then i grounded it full time from inside the car, before the wire gets to the ECU unit, no change in performence or the light, the sensor has been changed with a cheap bosch replacement, this year only calls for the single wire version. what powers the sensor light in the instrument panel? how do u reset it? how can u tell if the sensor is doing its job? so many questions..searched a lot of posts..havent found any real answers yet, thanks.
Newbie
Joined: Jun 2009
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2003 500SL; 1985 380SL
If I remember correctly, the manual for my 1985 380SL states that the O2 sensor bulb will come on after a certain mileage -- I forget the number of miles. At that point, the sensor bulb is to be removed. I have never seen a schedule for replacing the 02 sensor in the 380.
When I first got the 1985, I noticed the 02 sensor light did not light up when I turned on the ignition, so I removed the instrument panel and installed a bulb that burned all the time until I read the manual and removed the bulb.
Frank
When I first got the 1985, I noticed the 02 sensor light did not light up when I turned on the ignition, so I removed the instrument panel and installed a bulb that burned all the time until I read the manual and removed the bulb.
Frank
Newbie
Joined: Jul 2009
Posts: 2
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1984 380 SL
I just came across this in the manual:
"The mileage counter of tachometer generates a voltage by way of a magnetic field after attaining 30,000 miles. The subsequently connected electronic system picks up the voltage and then switches on the indicator lamp.
After changing the o2 probe, make warning device inoperative by removing bulb."
"The mileage counter of tachometer generates a voltage by way of a magnetic field after attaining 30,000 miles. The subsequently connected electronic system picks up the voltage and then switches on the indicator lamp.
After changing the o2 probe, make warning device inoperative by removing bulb."
