Hi,

I just get the w201 shop manual cd online. I need it to perform the troubleshooting procedure on my idle air control valve...

The m103 engine on the cd is for an older version 1987, at that time the OVP was supplying battery voltage to the IACV and they do not have MAS realy but fuel pump realy, the CSI was a 25 pin instead of a 50 some pin like mine.

On a 190e 2.6 1991 the the OVP (pin87L) feed the CSI and then the CSI feed the IACV, on mine the voltage isn't 12 volts, anyone know what the voltage should be.
Does the voltage change when the engine warm-up??
Anyone know or have the procedure to be perform on this model to check the IACV.
The IACV work well if I apply 12 V on it.

My other question is, my crank sensor read 500ohms (Hot or Cold) the specs say 680 to 1200 ohms... Should I replace it???

I' m after a Sudden Stalling Syndrom at -15 to -20 C°

Max

Duty cycle or milliamps

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Outside temp -10C°
Battery voltage = 12.5 volt

On/ off at the x11 socket

Between terminal 2 and 3

Cold
On/off
6 to 7 volts

at 80C°
no on /off
reading = 10 volts

At 85C°
On/off
9 to 10 volts

IACV
2 volts cold or hot

Is this normal???

Max

On that & most M103's the idle control is measured as a duty cycle.

In other words the current to that valve is a constantly changing voltage.

Should have a 30% duty cycle at the valve.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Hi M.B. Doc

If mine do not cycle but has always 2 volts what is wrong CSI or MAS ???

Again the car stall only when the weather goes below -15/-20 C°, engine temp at +/- 80C°, deceleration before turning, hard to start after, have to wait +/- 15 minutes sometimes idle up and down when I start it back, put in gear stop boncing....

Thanks for your help

Max

To get a proper measurement, you either need an oscilloscope or a meter that reads duty cycle. If your voltmeter is averaging accurately, then 2V would be close to a duty cycle of 2/12 X 100 = 17%. However, that is assuming a lot. Best to get the proper meter.

Steve

__________________
'91 MB 190E 2.3
'08 RAV4 Ltd 3.5
'83 Lazy Daze m'home 5.7

Hi Sbourg

I have 3 multimeters none seams to be able to read duty cycle.

-An old analog

-Blue Point model EEDM504 A

-Digital C-266

Any cheap dmm I could buy to do this duty cycle test ???

Thank for your help

Max

oscilloscope or the tools such as the modius by snap on can measure duty cycle

__________________
1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)