OBD2 Question

[Hopper]

Hope this is in the proper forum.
I bought a new OBD2 to help diagnose issues with my 99 TJ. I am new to all this and never have used one. My jeep is sitting at the mechanics getting frame sections put on so I tested it on my F250 since the check engine light has been on for years. I got the code that I expected then erased codes, the light went off and now shows no code. I am assuming after driving around awhile the light will come on and the code will reappear.
So back to making repairs on my Jeep. When I get it back and scan it in the future and get the code, do I then make a repair and if done right the code goes away? Or do I clear the codes drive around and see if it comes back?

 

[CodaMan]

Some codes clear themselves and other don't. After maintenance It is my practice to clear codes by putting the PCM into learn mode so everything gets recalibrated. To go in to learn mode, disconnect the negative battery terminal, turn on the headlights to drain any residual memory then touch the positive and negative terminals together for 30 seconds. After 30 minutes, turn off the headlights and connect the negative terminal. Now turn the key to the ON (not started) position for 15 seconds, next start the engine and let it idle for 10 minutes. Final step, drive as normal.

 

[pagrey]

Personally I don't disconnect the battery, the bad part about disconnecting the battery is it also resets the readiness monitors so you wont pass smog if your state checks that. All codes will clear but if they are emissions related you have to complete very specific drive cycles as described here.

http://www.obd2.com/support/reprog/downloads/chrysler/chry-imset_procedure.pdf

The DRB instruction manual in section 7-9 describes both "Reset Memory" and "Clear PCM - Batt Disconnect". Disconnecting the battery "will clear all PCM RAM (random access memory)." Reset memory will selectively reset various learned settings and "should be used after a repair has been performed. While the system would eventually adapt to the repair anyway, perform the reset and then drive the vehicle to help verify the repair." That's really straight from the horses mouth.

Personally I have the time to let the system adapt as they suggest but there's nothing wrong with following the advice given by @CodaMan. I don't personally like the term "learn mode" because disconnecting the battery neither re-learns the cam/crank sync or performs the quick-learn for the TCM among other things but I guess that's just a game of words.

 

[CodaMan]

Personally I don't disconnect the battery, the bad part about disconnecting the battery is it also resets the readiness monitors so you wont pass smog if your state checks that. All codes will clear but if they are emissions related you have to complete very specific drive cycles as described here.

http://www.obd2.com/support/reprog/downloads/chrysler/chry-imset_procedure.pdf

The DRB instruction manual in section 7-9 describes both "Reset Memory" and "Clear PCM - Batt Disconnect". Disconnecting the battery "will clear all PCM RAM (random access memory)." Reset memory will selectively reset various learned settings and "should be used after a repair has been performed. While the system would eventually adapt to the repair anyway, perform the reset and then drive the vehicle to help verify the repair." That's really straight from the horses mouth.

Personally I have the time to let the system adapt as they suggest but there's nothing wrong with following the advice given by @CodaMan. I don't personally like the term "learn mode" because disconnecting the battery neither re-learns the cam/crank sync or performs the quick-learn for the TCM among other things but I guess that's just a game of words.

The procedure I posted above is a requirement after most repairs on my F-250, but I figured it couldn't hurt one bit on my Jeep so I keep it simple and reset all my vehicles the same way. And being from a emission testing state I to always give my self a couple of weeks for the monitors to go ready.