Hi Again,

Since I've received several pmail offers to help but only one offer was
relevant, I think it better I post my instructions also on this thread so
whoever comes across this and thinks he can help too can join the
bandwagon...:-)

Basically, It's not very difficult - all you need to do is
connect a low power 12V source to the ISCU and measure
volatge at the outputs. Here is the ISCU pinout:

Pin         Pin
name        in
STAMPED     wiring
on
ISCU        diagram    Pin function
-----       --------   -------------

15           14        Switched +12V from ECU power
relay
LH           15        Power steering sensor input
31            5        Ground
ST1          11        Output1 to ISV (Transistor
Collector?)
ST2           4        Output2 to ISV
1            17        Ignition pulses from Ignition
coil driver
LS            8        Throttle valve switch input
T            13        Coolant temperature sensor
(TEMP2) input
K             2        A/C sensor input
50            6        +12V while starter is turning

The test power supply should preferably be regulated
and current limited to about 1A, but a 1A wal-wart
power supply will do, as long as you measure it's
output to be in the range of 11-14V. My ISCU draws
about 100mA at idle, with no load at he outputs, and
with the lamp should consume about 600mA. **DO NOT**
connect to a high-power 12V source such as the car
battery(!!!) because an inadvertant short might blow
something.
You should connect to pins 15 & 31 of the ISCU (+12V
to pin 15, -12V to pin 31. See attached image) and
tell me what you measure at all the other output pins
relative to ground (pin 31) and note if it's stable or
not.

Then, I need you to measure the voltage differential
between St1 & St2, and also to connect a low-power
test light (around 5W) across them and tell me if it
lights or not (it should IMO) or even connect a small
loudspeaker or earphones (carefull of the volume!) to
listen to these outputs and find if it's a variable
signal in addition to the DC average voltage measured
previously.
If you can record it with your sound card and mic and
send it to me, all the better...

** be very careful not to short any adjacent pins on
the ISCU so as not to cause
damage (I usually use insulated crocodile test clips)
**

More details at:
http://gerry.vanagon.com/cgi-bin/wa.exe?
A2=ind0709a&L=vanagon&D=0&X=73B5B23C72130053E4&Y=tinkerman007@yahoo.com&P=1
5729

I also need to know your exact ISCU model. Mine is
Part Number 251 907 393C, made by VDO.

Well, that's it. Not very difficult, and if you have
even minimal knowledge in electronics you can help.
Hope we can get this info moving soon...

Cheers, T-man.