Today, I disconnected the battery. Several hours later, I reconnected. Then I decided not to crank the engine over. Instead, over the course of a few hours, I went into the van and turned the key on, but did not turn it to run. I did this 10 times, during each session. Then waited a half hour or so, and did it again. On the 46th time, the engine light came on! That leaves me totally confused as to what this is.

The only thing that I can see that is triggered at key-on only, that might effect the IAC, is the ECT (engine coolant temperature sensor). The PCM sends a signal out to the ECT. From that point on, the PCM only sends out signals to the other elements (IAC, O2S), based on the data it has received from the ECT.

 

I understand that the DVD covers all of those vehicle, but you only can active one out of all of those vehicles listed, you don't get to install all of them. If you look at the 8th line down on the more details page you'll see that "Ram Vans 1999-2003" is listed. When installing the DVD you are prompted for the vehicle you want to activate out of all of those listed on the more details page and that vehicle is the only one to get installed. In your case it would be the Ram Van and that is the only vehicle you would have access to. Once it's installed you have a complete manual specifically for that one vehicle. This is not like the global/generalized manual like you've used at the library. Chilton groups many different vehicles on the DVDs this way so that they don't have to have a different DVD for every single vehicle.

The big bonus to having a DVD is that you can do a search instead of thumbing through a book looking for something specific.

 

Are you assuming that the light came on due to a code 0505 or did you actually do a code check? I ask this only because the IAC (like O2 sensors)isn't supposed to come into play until the engine is running. The ETC gets queried prior to startup only because the computer needs to adjust the air/fuel mixture based on engine temperature in order to start the engine correctly.

 

Hey you're not going to believe the post I just came across. [sm=happybounce.gif]
Remember that spark plug issue you had?????????????????????????????????

http://www.obd-codes.com/forums/666-...and-p0123.html
"So to make a long story short the TPS, IAC, and the PCM was replaced and the throttle bodywas cleaned. The engine light was still on. I guess when you tell the dealer that you will take it somewhere else and refund you your $$$$ they find out the problem quick. Turns out the newly installed spark plugs gap was not set right, and the engine light is now not on. Now I'm wondering was it necessary to replace the PCM, IAC and the TPS. The truck runs just like a newer one."

 

I checked the code!
I also did an instrument cluster check and all the lights and guages are functioning correctly. I went out a little while ago, turned the key on (no crank). The engine light is still on. I don't even think a mechanic could figure this one out. I have a feeling I would be taken for a whole lot of parts and still have the problem.

 

Three days ago, I pulled them all and rechecked the gap. All is okay! I found that post a while back. But, thanks for thinking of me.

 

From what I can tell, once that fuel mixture is set, then the PCM resets the plunger in the IAC. Could it be that the ECT is malefunctioning and sending the wrong info to the PCM, therefore making the PCM set that plunger in the wrong position. Then the IAC sends info back to the PCM that doesn't match what the IAC said and voila - light comes on?

 

No, because if the PCM is setting the IAC based on the ETC data, then the data the IAC sends back to the PCM will be exactly what the PCM is looking for.

 

I think I got it. I don't want to jump for joy to loudly, but I stopped and started several times, no light. So, I'll do just a little cheer - [sm=yeahsmile.gif]

Today, I went through everything suggested. Checked connections to the PCM, wires (again), etc.. I knew I had rechecked the new spark plugs; but after alloro's reminderabout the spark plugs,I got to thinking today that I had not rechecked the wires. I took one of the old wiresout and starting changing out the new ones, one at a time. I had a slight ticking in the engine, before I started. When I reached number one cylinder (second to last I checked), I put the wire on and the tick went away. I had a bad wire.I changed the wire, disconnected the battery for a while, and no check engine light.

That's two bad parts I got from Autozone recently. One was the rotor, which literally fell apart in pieces. Now the wire. Thanks to everyone for your suggestions and help.

Now, onto the next job - flushing the radiator.

 

Groan! [sm=escape.gif]

[sm=joke.gif]