No PMW idle valve output

[Mercman]

I'm megasquirting my mercedes R107. Up until now everything is going fine except for idle control which doesn't work no matter what I try. The engine (M103 6-cylinder) has a stock 2 wire PMW idle valve that does not respond to the ms controller. I have measured the output with a standard digital voltmeter connected between +12v and the FIdle output wire and this is what I read:
- MS off: 150 milliVolt
- MS on: 40 milliVolt
- MS on, Idle Valve test mode: 150 milliVolt. Changing the idle duty % or the frequency does not make any difference, I always get 150mV.
Any suggestions? Could I have blown up the TIP121 transistor during assemby or testing?

Regards,
Ray

[nathaninwa]

Have you tried changing polarity at the valve? I've noticed with the ford pwm valve its +/- specific and most aftermarket harness's are a single color making you think it's not

[Mercman]

I've alreadty tried switching the polarity but that makes no difference.

[WillExoIX]

I have a thread with a similar issue and DaveEFI has posted a way to check the Fidle output in my thread. http://www.msextra.com/forums/viewtopic.php?t=58689

[duxthe1]

I run ms2e on an m103. Correct me if im wrong but shouldnt you be measuring to ground not 12v?

Do you have a diode across the valve? Made a big difference on mine. Research it if not and add one.

A few settings:
Mode=normal 0=off
153hz
valve closed duty= 44
Valve open duty = 86

The valve defaults to 20% open. As you add pwm it closes and stays closed until about 45% From 45 until 85% is the usable range.