If you've been following my posts you know that when you lose battery power you lose adaptive memory. Lose adaptive memory and some things won't work properly until the adaptives are relearned. We'll be looking closely at idle control adaptives on this one but only after making sure we have a good battery.
The truck idled with no stalling when I drove it into the shop. This means the computer had probably relearned idle on the way here. I wanted to save the adaptive memory but I needed to test the battery. A memory saver will keep the computer powered while you disconnect the battery and you won't lose adaptives.
The old battery was bad, so out with the old and in with the new.
Once the replacement battery was installed I removed the memory saver. Since the idle adaptives were relearned and since I saved learned idle I could look at idle air control counts for a problem. There are some things you can only see with a scan tool. IAC counts are one of those things. The ideal range here is 10-24. If you see higher numbers the computer is having to command more idle air to maintain idle speed. Usually there is a buildup of carbon on the throttle causing this. 107 here meant the throttle plate might be dirty.
After cleaning the throttle I checked the counts again.
They were much better but still higher than our target range. I knew the throttle was clean. There is a minimum air adjustment that can be checked. Very easy to check when your scan tool will command it. Minimum air takes the idle control motor out of the picture. Only the air allowed past the throttle is maintaining idle speed. Just enough rpm to not stall when placed in gear is my rule of thumb. The minimum air was fine. Using the scan tool I did a minimum throttle relearn twice. I've ran into that before on Dodges, sometimes more than one relearn. But it worked.
Thanks for reading!
Kenneth Hayes
G&G Auto Repair
No comments:
Post a Comment