Windstar 1998 Service Engine Light Code

The code I obtained was P1537

Manf. Cntrl Veh. Spd.
Idle Speed Control
Auxillary Inputs

I searched for P1537 and found plenty of hits but not matching the above words.
Please let me know how to debug which manifold control is being referred to here.

Thank You!

ok i'm going to have all day tomorrow to work on this issue and really need a hand here if someone can help me out.
I've determined, I think, from reading posts, that there is a vacuum problem.

When I remove the vacuum line from the front side actuator, the one behind it seems to engage. I also feel vacuum here. When I remove the vacuum line from the rear actuator, nothing happens, and I feel very little vacuum on that one. What I don't understand is I though I read they both got their vacuum from the same place, so, shouldn't they both not have vacuum?
Also, when I turn the engine off, I can catch an air leaking kind of sound while it is shutting off, but cannot recall if it has always done that or not because I'm thinking of trying to find a leak somewhere.


If it is a vacuum leak, how do I get to the hoses? They seem to be behind the induction where I can't see well? Do I remove the hood and cowl to get to the rear part of the motor?


thanks for any help here!

has there been any other replacement IMRCs come available cheaper than fords that work? Has anyone gotten lucky at junkyards getting working ones?

There were a few posts about problems with the aftermarket ones.....don't know if it was corrected or not.
Used ones are risky as they might be defective also......the diaphrams only need a small hole or crack to be defective.

Both actuators share the same vaccum source......so 1 leak can take them both out.....but only 1 is defective.

There were a few posts about problems with the aftermarket ones.....don't know if it was corrected or not.
Used ones are risky as they might be defective also......the diaphrams only need a small hole or crack to be defective.

Both actuators share the same vaccum source......so 1 leak can take them both out.....but only 1 is defective.

I did finally figure out it was one bad actuator, and was able to wire it closed and things seem to be running fine. Now I can save up for some replacements. I think I will try to locate some used ones though if I can test them before hand, I assume if they hold a vac from a hand pump they would be ok for a while. thanks