volmark

So I cleared this


I had battery neg off for an hour and after cleaning tbody put all back and drove. Ck eng light did not return like before. However after obd says p0401 pending and the cat and other sensors are not complete. I've read about drive cycles I get that it make take a few days driving back to work etc. But did pulling neg actually clear code? Dude at advance said hold neg and pos together to reset pcm. Did not do this as I don't want to fry it

volmark

I read that a pending code means that I failed to complete 1 drive cycle properly. And that I need to complete 2 drive cycles in a row to clear the code? Anyone else having issue after a fix to get through the drive cycles? Am I understanding this correctly?

i am reading here http://www.obdii.com/drivecycleford.html

Jbrew

Yea, if you connect the pos and neg together it drains the KAM (KeepAliveMemory) capacitor and you don't have to wait 15 minutes with the neg disconnect. It's how all capacitors are drained, you just cross them out.

Nah, you won't fry anything.

BTW the battery should of been disconnected when working on her. Should always disconnect the battery.

volmark

ya i said after but i meant before during and after so at least 1 hr probably 2 total to remove clean and reassemble. So puling the neg will clear the code completely then?

Jbrew

No, you have to wait 15 to a half hour. Then yes, that will clear the KAM.

w0lvez

Why not just use the OBD to reset your PCM? After reseting the PCM start the engine without any electrical load and let it idle for few minutes. After 5-10mins in Park or Neutral. Let the vehicle learn the proper idle in D before turning on the AC and add some electrical load after few minutes.

Jbrew

You mean adaptive strategy ? Or are you referring to the scanner ?

w0lvez

Try resetting the PCM while the engine is in operating temp while the Radio, AC, Ligths are ON then quickly shift it to Drive. Drain the battery for few minutes to make sure it's not fully charge to add electrical load on the alternator. The PCM will learn to idle below the normal RPM and will stay low.

Jbrew

I guess I can't answer your question if you don't answer mine. Your didn't quote anyone, so it's hard to determine who that was directed to.

I'll comment on what you posted tho, -

What you described is by - some of the book, I'm not sure if the other stuff is in there but it might be. You can use the AC if desired, but defrost works just as well ( a point of info), your turning the same parts.

IME, -As far as the other stuff , well including AC or defrost actually, adaptive strategy dials them in quickly. Sure if you want to spend the time to go though those procedures by all means do so. Take notice of the outcome. It's the exact same you get just firing her up and letting the truck get to operating temp without pushing buttons, this and the other.

Shift points will auto correct via the way you drive her. Fine tuning, adjustments are always happening, never quits.


Seriously, try them both.

Jbrew

Yes two for the O2's, just consecutive, they can be spread out over time. Once the second drivecycle commences, if the O2's aren't in readiness you'll know within about 10 minutes.

Not sure you got that one answered.

_______________________

The EVAP can be finicky if you attempting to force run. You can do everything right and it may not work. You have to repeat the procedure, sometimes 4 times before you get it to run or bypass. It can be stubborn.