Should the "o2" warning lamp illuminate when ignition turned on? - PeachParts Mercedes-Benz Forum

86560SEL · #1 01-14-2007, 01:31 AM

It may be in the owners manual, but I thought I would ask here first so I would not have to search, but does anyone know if the "o2" warning lamp is supposed to illuminate when the ignition is turned on?

I am wondering, because I have never seen mine illuminate, but ALL other lights work perfectly. I know that on most cars, that most lights will have a "check" moment, where warning lights illuminate, but I know there are some that do not. Oh, BTW - its a 85' W126 380SE.

Thanks!

Gary Ganaway · #2 01-14-2007, 03:09 PM

I don't believe mine comes on either but I will check it next time I start it up

Wait, I forgot,can't do this because I just dropped car off for new chain, guides, tensioner and tensioner guide. Will check when I pick car up on Wednesday.

86560SEL · #3 01-15-2007, 08:30 PM

Thanks! Much obliged.

Have them change my chains, guides, rails and tensioner as well while they are at it. LOL.

Mike Freeman · #4 01-16-2007, 05:15 PM

86 & 87 420 SEL and 560 SEL have a circuit in the CIS-E control unit that turns on the O2 sensor bulb. The bulb should come on with key on and engine not running.
If the bulb does not light it has probably been removed.
Mike

86560SEL · #5 01-17-2007, 01:35 AM

Thanks, but its a 1985 380SE.... not sure if they would be different from the 86'+ setup or not.

My "username" is from before. I have a 85' 380SE now. I suppose I should change my username, as many people often assume that I have a 86' 560SEL. I wish I did, but I don't.

Quote:

Originally Posted by 86560SEL

its a 85' W126 380SE.

lkchris · #6 01-17-2007, 10:19 AM

If it was DESIGNED to never come on, how would you know the bulb wasn't burned out?

Of course it's supposed to come on. Who cares which model?

86560SEL · #7 01-17-2007, 11:20 PM

I asked, because on some cars- not ALL warning lights are designed to come on when the ignition is turned on. I was not sure if this light on this car was one of those exceptions.

Who cares which model? It may not matter, but because of my username, I assume he thought that I had a 86' 560SEL, but mine has a different engine (3.8L) on the slightly older body style, so I did not know if that would make a difference or not. They changed quite a bit from 1985 to 1986 in many areas/updates. So there. Also, if it is supposed to come on and its not the bulb, I was wondering if there would be any other reason it would not illuminate.

Thank you.

Quote:

Originally Posted by lkchris

If it was DESIGNED to never come on, how would you know the bulb wasn't burned out?

Of course it's supposed to come on. Who cares which model?

86560SEL · #8 01-27-2007, 10:31 PM

GARY - did you get your car back yet?

Gary Ganaway · #9 01-28-2007, 04:58 AM

yes I did and it runs great...I did turn the key on and my 02 light does not come on. This was about a week ago but I will check this out again and let you know.

Gary Ganaway · #10 01-28-2007, 10:27 AM

Just read the manual and the 02 sensor light will come on when sensor needs replacement. It does not come on when turning the key to position 2. The manual states that he oather gauges( ABS low fuel reserve, charging, etc do come on when ignition switch is turned to position 2

86560SEL · #11 01-29-2007, 09:00 PM

Thanks Gare.... I never thought to look in the owners manual.

Seems like all is normal then, because all of my other warning lamps work properly.

Thanks again.

Quote:

Originally Posted by Gary Ganaway

Just read the manual and the 02 sensor light will come on when sensor needs replacement. It does not come on when turning the key to position 2. The manual states that he oather gauges( ABS low fuel reserve, charging, etc do come on when ignition switch is turned to position 2