I keep reading that you should reset your pcm after you change certain parts. 2 questions 1) what parts and 2) how do you reset it?

 

i believe your referring to..
1. disconnect neg terminal on batt
2. turn key to start hold for 30 seconds
3. reconnect neg terminal on batt

basically it resets every light (cels) that are drawing power from the batt.

 

Oh hell I thought it was scientific procedure or something. I kept reading in these threads where you are supposed to reset your computer when changing out certain parts. I have an OBD-II Scan tool that I use to read the CEL codes and erase them with. Thanks anyway.

 

can anything happen if you do this... like something bad???

 

It doesn't reset the CEL or codes ... it dumps the learned behavoir in the PCM that is no longer valid due to altered configuration (changed parts). The computer is reset to a default factory configuration and it will relearn how you drive over a few days or so.

 

OH! OK! So after what parts should one do this?

 

Disconnect the battery and turn the key to crank. It will take less than a millisecond for all the energy to dissipate from the system. By the time you get back to the battery, all the caps will have discharged and it will be clear.

 

So I'm not actually holding the key all the way forward as if I'm starting the vehicle just forward to where if the battery was connected it would light up the dash?

 

Can someone tell me after what particular parts should I reset the pcm?

 

Turn it to crank for fastest effect.

Anytime you do an air filter, change engine parts or something like that you reset the PCM.