what is this strange box with a knob on it? 1995 E320 wagon
 

So I was digging into the dash of my e320 wagon trying to "fix" my combination stalk when I came across this strange box with a knob on it

http://sphotos.ak.fbcdn.net/hphotos-..._6796029_n.jpg

timing reset? magic mpg increaser?

I think that's what's called the MAS relay? I believe it's related to the fuel pump.

-J

Correct, a MAS relay, the knob is for removing the relay.

I noticed the same when I had the dash apart on my '95 E320 wagon. I thought it was related to the security system.

The MAS relay is supposed to be behind the battery IIRC. If this is under the dash, it might be a similar looking device.

But first thing comes to mind is the MAS relay for me too. This controls the fuel pump, among other things.

Too bad...no magic
 

engine control unit.

Not a MAS relay unit!!

That is the ODB1 diagnostic module that records check engine information.

Cool :cool: What fuel injection system would a 95 E320 have? Are they LH Jetronic or were they still CIS?

-J

HFM-sfi

Hot Film Management

I'm going out on limb here but i guess your car is a California version of E320 and this a diagnosis control unit with the part number A0155454332. Just shoot me if i'm wrong.

sfi = sequential port injection in this case?

Does the fuel injection computer also control the ignition system?

-J

Yes, & Yes

Yes & No, it is a 104 with SFI, but the ignition was not integrated until ME-SFI

BTW the LH-SFI and HFM-SFI are essentially the same, the only real difference is the mass airflow sensors, the LH being hot wire, and HFM being hot film.

I wouldn't argue about the control unit until I saw where it is. Based on where I believe it is I still think it's a MAS, MBdoc could be right, it's definitely not the engine control module though
Gilly

Oh I see what you are saying, no the MAS is not the engine control unit. MB can be very flaky on their descriptions, N16 is the MAS, which is NOT the engine control unit. In that drawing the engine control unit would be one of the larger control units towards the top of that drawing.

So wouldn't that actually make this Motronic?

-J