It started smoking and the unit that it is attached to wouldnt turn off until i unplugged the sensor. Does anyone know what went wrong or what sensor device this is?

 

The picture is of the Air Injection Pump, not a sensor.

Here are the possibilities :

1. the pump is still OK, but the relay contacts are welded in the RCM ( Relay Control Module )
2. the pump is toast AND the relay contacts are melted in the RCM.
3. the pump is toast and the relay contacts have released, but are still badly burnt.
4. same as 3, but pump is OK.

if 1, then you will need to repair or replace the RCM
if 2, then you need a pump and an RCM
if 3 same as 1
if 4 same as 1

See the thread about 'Mystery no start' that relates to the RCM.

note : the relay on the RCM board that controls the pump is a different relay type from the other 3 - it is heavier duty and located at the rear as the module sits in the car. ( the RCM is the one in the black box by the battery closest to the engine )

http://www.car-part.com/cgi-bin/search.cgi - look for 'Smog Pump' and ask for MB part number 170 545 0305 on the RCM.

 

The relays are all the same, they have the same number stamped on them, #5706. The fuse is bigger, it is #5 and it is 40amp.

 

Dave, you are both correct, and incorrect.
I was going by memory from when I examined the RCM that rayth sent me ( that I forwarded on to tighed1 ).
I wrote all the relay numbers down from that one, and it did in fact have a 5708 relay in the air pump location, while all the others were 5706 like you stated.
I just went out and removed my RCM, and you are correct there, they ALL are 5706.

BTW, did anyone ever figure out if we could order & replace these relays ?

 

If they had different relays in them we can rest assured that the RCM would have a different part number. That is the way the part numbering system goes, you change a part in the assembly and the whole assembly number HAS to change.
Therefore the RCM part number of the part with a 5708 relay in it would be different to the RCM part number with all 5706 relays in it. The same RCM part numbers means they have the same relays in them, that's DIN and ISO policy.

How to change a relay in the RCM.

 

Thanks, Dave. I didn't write down the part # on the RCM that I sent to tighed1, so
I guess this discussion ends with you, as usual, being right and me being a stupid s**t.
You are indeed the wise wizard of the North.

Did you ever order and replace any of those relays ?

 

I hope I'm correct, I did study this RCM some time back and fortunately I do not have any experience in replacing any of these relays.
I would replace any relay when it is burnt, it requires a nice polished/burnished domed surface to prevent future sparking damage again.

I think but cannot prove as yet that burns are caused by poor grounding on this pump. Maybe Rudy would have some input here.

This pump is a PITA. I think you can blank it off.

 

Yes, I am quite familiar with relays, in a former life as a NCR field tech, one of the pieces of equipment I serviced was a card punch built by BULL in France, that thing had somewhere around 250 relays in it, and the interesting thing was that the feed to energize the coils also went to the case of the relay so you could tell if a relay was 'on' by metering the case.......