Mass Air Flow sensor hook up

[douglasdearmond]

I have a Mass Air Flow sensor (hot wire version) that is for Mercedes S500 94-99. It is a Bosch 0.280.214.004 (new number 0986.280.121) It has a 5 pin circular connector. I need to know what the 5 connections go to so I can hook it up to a new fuel controller for the hobby racer. If anybody has a wiring diagram for S500 I would really appreciate letting me know what the hook up is. Thanks!

[MB STARS]

What years is your s500 92 to 95 is LH-SFI, 96 to 99 is ME-SFI ??

[douglasdearmond]

Actually it is going on a Porsche but the information I have is the MAF sensor I have was used on a 92-93 S500 Sedan and a 94-99 S500 Coupe. M119.970-140.051 and M119.970-140.070
The information could be inaccurate though. It is a Bosch #0986.280.121 (old number 0.280.214.004). I think I identified pin #5 as power and pin#1 as ground but I am not sure about the other three. I am needing to hook the unit to a Link Intercept controller with the package replacing the old air flap style air flow sensor. Thanks a bunch for your help, Doug

[MB STARS]

Doug
number 2.3.4 wires are coming from N3/1 LH-SFI module Ingition on between pin 5 & 2 1.0-1.2 VDC or engine at idle ETC >70c 1.3-1.7 VDC voltafe raises with RPM pin #4 12 V with ignition on pin #3 ignition off disconnect N3/1 and reconnect after 5 sec start engine ECT>60c RPM >2000 for 15 sec after 5 sec approx 3-5 VDC fpr 1 sec hot wire will glow at the same time.
pin 1 is ground. this is for 1993-1995 engine 119 LH-SFI only.

[romanbuhr]

Dear MB-Stars and Doug,
my name is Roman, I am from Germany and own a R129 and a W124.
I am sourcing/collecting some excellent and expensive replacements parts for these cars, so I bought 2x MAF Hotwire Sensors (the aluminium one with round, 5 PIN plug) and I dig out this post as I have the same problem as my predecessor: I would like to test the MAF. Unfortunately I dont have a M119 engine at place at the moment, so I go for an offline test with help of an air blower, a throttle body and an oscilloscope.

All what I need is the what to put on which PIN.
I have to say, that I did not fully understand the last post from MB Stars, so If somebody can be so kind, to tell me what to put on which pin?

I figured out, that PIN 1 is ground and that there may be PINS for the "Burn free" circuit of the hotwire. I assume, that there a 12Volts and 5 Volts PINS and at least one
signal-return wire to the LH control module.

PIN1: Ground
PIN2:
PIN3:
PIN4:
PIN5:

Any help would be aprreciated.
Thanks.

-Roman