Just changed my IAC and gave the MAF sensor a good cleaning. First time have done anything to both these parts after 158K miles on my 03 Escape 3.0

Should I reset the on board computer (Disconnecting both positive and negative terminals from battery for 1/2 hour or more)?

The IAC was really covered with black carbon buildup it looked like. Was hard to tell with the MAF, but really gave it a good soaking with CRC MASS AIR FLOW SENSOR CLEANER. I guess I could of cleaned the IAC as well, but opted just to replace it. $84.50 from my local auto parts place. Remind you there are two different IAC's available depending on the build date of the 2003 Escape. I had to give them the build date to get the right IAC.

I haven't heard it is necessary to reset the computer, but just wondering if now that these two parts were cleaned and changed will it affect the computer's programming of the settings for the engine, like richness or leaness of the fuel/air combo going to the engine?

 

Yes but no need to pull the positive just the negative is enough and five minutes is plenty of time.

 

That's what I had thought.

I think I read on this forum somewhere that you must pull both negative and positive terminals off the battery because you the battery still could be grounded at some other point in the vehicle. Also in the same post it said it takes up to a half hour for the memory to clear.

Either way, I will clear the on board computer.

Thanks.

I had two instances in the past few months were the vehicle would not idle at all. Took about 4 or so tries before I got the engine to stay running. My mechanic said 99% of the time it is the IAC. He said he could clean it or change it for me, but it is a simple task and I could do it myself and save some bucks. He said while I was at it, I should clean the MAF sensor. So that's what I did.

 

If you disconnect either cable, you break the circuit at the source, that's it. Nothing else matters.

 

That's what I always thought also.

I will try and find that post. Maybe there was more to it or I read it incorrectly. Almost sure though it said to disconnect both terminals. Whatever.

 

There was one user someplace that suggests, remove the positive battery cable only and touch the negative post therefore draining any residual voltage quickly.

 

How come when I disconnect the negative terminal for 5 or 10 minutes, my radio does not lose the preset radio stations?

 

Because of a certain type of chip inside that retains the info without constant power being applied. It might lose the stations over a real long period of time.

 

True, but check your other settings on the radio. Time sets back to 12:00, all of your personal settings like bass, treble, fader, balance are all set to the mid setting.

There is probably a RAM chip of some sort to keep the preset radio stations from resetting.

Here is an article on e-How to reset the computer in your vehicle:

How to Disconnect a Car Battery to Reset the Computer | eHow.com

 

The dealer drop a new battery in mine without even telling me and nothing changed.