99 windstar P1518 idle speed/air control motor??

[windstarbluesman]

Hi guys, just got a recent "check engine light" while sitting at a light. So I took it to Advanced Auto to have the code read. The code was a P1518 malfunction control vehicle speed (idle speed control) auxiliary inputs.

I have a 1999 windstar 3.8 engine and couldn't find any info on the idle "speed" control motor, but lots of info on the idle "air" control motor for my windstar. Is this the same motor part that is just labeled "air" instead of "speed" for the ford windstar?? The guy at Advance Auto store indicated that I needed to replace to "air" control motor for this code. I'm thinking he's probably right about this but just wanted to check with this forum first before I throw down the $60 bucks for the part.. Thanks...

[olopezm]

Hi there, hopefully it will be only a disconnected linkage, take a look at this post regarding the same problem:

http://www.automotiveforums.com/vbulletin/t377809.html

Best regards,

Oscar.

[windstarbluesman]

Originally Posted by olopezm

Hi there, hopefully it will be only a disconnected linkage, take a look at this post regarding the same problem:

http://www.automotiveforums.com/vbulletin/t377809.html

Best regards,

Oscar.

Oscar, thanks for the reply. Still having a very fuzzy picture of the whole problem triggering the p1518 code though. It seems your thread link indicates the problem around the actuator area by the serpentine belt on the opposite side of the engine from the idle air control.

I first need to rule out that the use of the term "air" and "speed" control motor are not the same part indicators on a 1999 windstar. Any help with these two labels?? thanks...

[olopezm]

Originally Posted by windstarbluesman

Oscar, thanks for the reply. Still having a very fuzzy picture of the whole problem triggering the p1518 code though. It seems your thread link indicates the problem around the actuator area by the serpentine belt on the opposite side of the engine from the idle air control.

I first need to rule out that the use of the term "air" and "speed" control motor are not the same part indicators on a 1999 windstar. Any help with these two labels?? thanks...

You're welcome, both terms refer to a different part, the term air refers to the Idle Air Control valve (IAC) which is located at the throttle body if this component goes bad you'll have idling problems specially on a cold engine (it varies from erratic RPM's to a car that won't idle at all), I'm not sure about the term "speed" the p1518 definition does not contains any "speed" in it:

P1518:Intake Manifold Control Runner Malfunction (stuck open).

Here is a short theory about the IMRC:

Intake Manifold Runner Control (IMRC) The air induction system improves engine performance by using the IMRC assemblies as follows:
1. The lower intake manifold has two runners per cylinder, feeding each of the intake ports in the cylinder heads.
2. The IMRC assemblies are located between the upper intake manifold and cylinder heads, providing two air passages for each cylinder.
3. One air passage is always open and the other passage switches from closed to open by means of a valve plate.
- Below 2450 rpm, this valve plate is closed to improve fuel economy and emissions.
- Above 2450 rpm, this valve plate opens to improve high speed engine performance.
The valve plates are opened and closed by the IMRC electric actuator, which is controlled by the PCM.

Finally here are two PDF's one with the location of the most common components at the engine compartment and one with troubleshooting info for the IMRC.

IMRC Troubleshoot
Common components location


I'm sorry that I didn't upload the files directly to the forum, but they are bigger than 100KB.

Best regards,

Oscar.

[windstarbluesman]

Oscar, again, thanks for your concern with this problem. Things are becoming much clearer now. I have downloaded your pdf files and will begin troubleshooting the IMRC unit tomorrow. I'll post the results of my findings once finished...or perhaps some more questions!....you never know till you open the hood...