I'm amazed at the wealth of information that is the Ford Service Manual CD.
The IMRC box is controlled by a binary, on/off signal from the PCM so it is indeed possible to replace the IMRC vacuum solenoid with it.
When the IMRC pin is grounded, the IMRC plates open..and this is applicable to both the vacuum-driven systems and and the cable-driven systems. The HU25 test below, which I copied out of the Powertrain Control/Emission Diagnosis manual, is for BOTH types of systems.
EDIT:
A relay will be needed:
'96: Secondaries open with IMRC pin grounded.
'95: Secondaries closed with IMRC pin grounded.
My information from the '95 comes from the '95 PowertrainControl/EmissionDiagnosis manual.
To get around this, a relay is needed. Connect the relay coil between VPWR/12V and the IMRC pin.
Connect the normally closed terminal to ground. Connect the common terminal to the IMRC box.
The relay is used as a logical inverter to cause the IMRC to work the way it should. When the relay coil has power, the normally closed terminal is open. Therefore the IMRC box is not getting power. When the relay coil has no power, the normally closed terminal is closed and the IMRC box is getting power.
HU25 VERIFY PCM IMRC DRIVER
l Key off.
l Reconnect IMRC actuator.
l Breakout box installed, PCM disconnected.
l Key on, engine off.
l Jumper IMRC Test Pin to Test Pins 51 or 103 (PWR GND) at the breakout box.
l Do the IMRC plates open?
Yes
REPLACE PCM. REMOVE breakout box. RECONNECT all components. RERUN «Quick Test».
No
REPLACE IMRC actuator. REMOVE breakout box. RECONNECT all components. RERUN «Quick Test»
Last edited by brianl703; 01/16/04 03:52 AM.
