What exactly does the power steering pressure switch do? It has come off and I didn't notice any difference. Also, the new A9L computer that I'm putting in doesn't suport a power steering pressure switch. Should I leave the switch open or should I close it permanently?

 

It tells the ECM that you are applying a load to the engine, and it raises the idle speed. It's very similar to the switch that raises the idle speed when you turn on your AC.

Take care,
-Chris

 

That should mean that if the A9L computer I'm going to put in there doesn't have any pressure switch input, I can just leave the switch open, can't I?

 

I don't know if the AL9 has it or not, but you're going to want it. Otherwise, everytime you crank your wheels when you are not moving, the engine will stall.

Take care,
-Chris

 

Well, the A9L does not have an input for the power steering pressure switch (and neither for a knock sensor, for that matter ).
Don't you think the computer will detect the load and compensate by increasing injector_open duration? How does the Mustang keep from stalling without the pressure switch?

 

The Mustang has a much lighter steering system. You are comparing a light sports car to a heavy truck. Think about it.

Take care,
-Chris

 

Ah, makes sense! I guess I'll just have to learn to live without knock sensor and power steering pressure switch, then!
Thanks!

 

Have you tried this yet? Try it out and if it doens't run right try using an A3M1 computer instead. I have the FMS Mass-Air conversion and it uses the A3M1 computer. NOTE: I THOUGHT the A3M1 was a factory refurbished version of the A9L so I don't think there will be a difference either eay..

Jerry

 

No, it's not in the car yet, but I already left the knock sensor and power steering switch out of my wiring harness... I guess I'll have to tear it apart again, if it doesn't run right.
From what year is the A3M1?