Proper way to reset computer
Proper way to reset computer I was pondering resetting my main computer. I had heard that after a certain amount of miles and mods, it wasn't a bad idea to do that. So i'm thinking you just disconnect the negative battery cable, let it sit for about an hour, and then start it back up, let it idle for a bit, and then your good to go right? Is it even worth it to do it with the mods i have now. I don't have auto-tap or anything, so just letting the computer reset itself is the best i can do.
TECH Apprentice
Joined: Apr 2002
Posts: 318
Likes: 0
From: Lake Charles Louisiana
Re: Proper way to reset computer That will work. The other way is to turn on key, remove the PCM Batt fuse and the PCM ing fuse. Let sit for 5 minutes and turn off key and reinsert fuses. Start car and let idle for 5 minutes. This will do some system checks including O2's. It will also do a idle relearn. Also the car must be at outside temps. So do it after the car has been off for awhile.
TECH Resident
Joined: Jan 2002
Posts: 754
Likes: 0
From: USA
Re: Proper way to reset computer The PCM has 3 types of memory.
The flash is where the running code resides.
Calibration tables are stored either in the RAM or NVRAM.
If you disconnect the power to PCM for just a few minutes, your only clear out the RAM contents.
If you leave power off PCM for hours then the capacitors in PCM leak down and only then is the NVRAM cleared out.
To speed up the process, if both battery cables are taken off the battery and the cable ends shorted together would speed up the caps draining.
A negative of dumping the memory(s) is ALL I/M 240 smog tests are forced back to a non complete state and it can take as much as 40 valid drive cycles for those tests to get back to a completed state, thus until they are the dinky CPU of PCM is forced to spend computer time doing those tests rather then using the CPU time to monitor and make calibration changes.
Keep in mind the CPU is less then 17 Mhz speed.
<small>[ July 02, 2002, 02:43 PM: Message edited by: Team ZR-1 ]</small>
The flash is where the running code resides.
Calibration tables are stored either in the RAM or NVRAM.
If you disconnect the power to PCM for just a few minutes, your only clear out the RAM contents.
If you leave power off PCM for hours then the capacitors in PCM leak down and only then is the NVRAM cleared out.
To speed up the process, if both battery cables are taken off the battery and the cable ends shorted together would speed up the caps draining.
A negative of dumping the memory(s) is ALL I/M 240 smog tests are forced back to a non complete state and it can take as much as 40 valid drive cycles for those tests to get back to a completed state, thus until they are the dinky CPU of PCM is forced to spend computer time doing those tests rather then using the CPU time to monitor and make calibration changes.
Keep in mind the CPU is less then 17 Mhz speed.
<small>[ July 02, 2002, 02:43 PM: Message edited by: Team ZR-1 ]</small>
