Go Back   DodgeForum.com > Dodge Trucks > Dodge Ram > 2nd Gen Ram Tech
Sign in using an external account
Register Forgot Password?


2nd Gen Ram Tech 1994-2001 Rams: This section is for TECHNICAL discussions only, that involve the 1994 through 2001 Rams. For any non-tech discussions, please direct your attention to the "General discussion/NON-tech" sub sections.

How do you reset the pcm

Reply
 
 
 
 
Thread Tools Search this Thread
  #1  
Old 03-03-2009, 08:23 PM
mcss8541's Avatar
mcss8541 mcss8541 is offline
All Star
 
Join Date: Feb 2007
Vehicle: 98 RAM 1500 4X4
Location: EL CAMPO, TX
Posts: 946
Question How do you reset the pcm

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?
This ad is not displayed to registered and logged-in members.
Register your free account today and become a member on Dodge Forums!
__________________
98 DODGE RAM 1500 SPORT 4X4 5.9L 6" LFT W/3" BODY LFT; PRO COMP WHEELS 8089 AND 35X12.5R17 DUNLOP RADIAL MUD ROVERS; CUSTOM FRONT BUMPER, Flex-a-lite dual electric fans , MOPAR rnd K&N 14X3"aircleaner;headers, Flowmaster Super 40
Reply With Quote
  #2  
Old 03-03-2009, 08:42 PM
96RamSLT 96RamSLT is offline
Veteran
 
Join Date: Feb 2009
Vehicle: 2004 ram 2500
Location: Wernersville, PA
Posts: 314
Default

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.
__________________

"Don't forget to clean your Muffler Bearings"
Black Truck Club #134
PA Truck Club #1
Reply With Quote
  #3  
Old 03-03-2009, 08:52 PM
mcss8541's Avatar
mcss8541 mcss8541 is offline
All Star
 
Join Date: Feb 2007
Vehicle: 98 RAM 1500 4X4
Location: EL CAMPO, TX
Posts: 946
Default

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.
__________________
98 DODGE RAM 1500 SPORT 4X4 5.9L 6" LFT W/3" BODY LFT; PRO COMP WHEELS 8089 AND 35X12.5R17 DUNLOP RADIAL MUD ROVERS; CUSTOM FRONT BUMPER, Flex-a-lite dual electric fans , MOPAR rnd K&N 14X3"aircleaner;headers, Flowmaster Super 40
Reply With Quote
  #4  
Old 03-03-2009, 09:38 PM
nathangfnd nathangfnd is offline
Captain
 
Join Date: Apr 2008
Vehicle: 1999 Dodge Ram 1500 5.9l 360 V8
Location: Grand Forks, ND
Posts: 731
Default

can anything happen if you do this... like something bad???
__________________
1999 Dodge ram 1500 Lifted 5 inches with 35s and to much other stuff

2008 Dodge ram 1500 laramie mostly stock with dual exhaust
Reply With Quote
  #5  
Old 03-04-2009, 12:38 AM
TMS Bill's Avatar
TMS Bill TMS Bill is offline
Record Breaker
 
Join Date: Jul 2006
Vehicle: 07 2500 5.9L CTD 4x4
Location: Warren, NJ
Posts: 2,403
Default

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.
__________________

Silver Truck Club member #26
98 1500 4x4 SLT Laramie Quad
5.9L Auto 3.55 LSD 285/75R16 BFG AT T/A KO DT PROFAB Adjustable Trac Bar MP PCM Crossdrilled/slotted rotors GM 1-ton brake mod
Reply With Quote
  #6  
Old 03-04-2009, 01:01 AM
mcss8541's Avatar
mcss8541 mcss8541 is offline
All Star
 
Join Date: Feb 2007
Vehicle: 98 RAM 1500 4X4
Location: EL CAMPO, TX
Posts: 946
Default

Quote:
Originally Posted by TMS Bill View Post
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?
__________________
98 DODGE RAM 1500 SPORT 4X4 5.9L 6" LFT W/3" BODY LFT; PRO COMP WHEELS 8089 AND 35X12.5R17 DUNLOP RADIAL MUD ROVERS; CUSTOM FRONT BUMPER, Flex-a-lite dual electric fans , MOPAR rnd K&N 14X3"aircleaner;headers, Flowmaster Super 40
Reply With Quote
  #7  
Old 03-04-2009, 01:03 AM
Viper37 Viper37 is offline
Banned
 
Join Date: May 2008
Location: The Communist Puppet State of Mexifornia
Posts: 1,031
Default

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.
Reply With Quote
  #8  
Old 03-04-2009, 01:05 AM
mcss8541's Avatar
mcss8541 mcss8541 is offline
All Star
 
Join Date: Feb 2007
Vehicle: 98 RAM 1500 4X4
Location: EL CAMPO, TX
Posts: 946
Default

Quote:
Originally Posted by Viper37 View Post
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?
__________________
98 DODGE RAM 1500 SPORT 4X4 5.9L 6" LFT W/3" BODY LFT; PRO COMP WHEELS 8089 AND 35X12.5R17 DUNLOP RADIAL MUD ROVERS; CUSTOM FRONT BUMPER, Flex-a-lite dual electric fans , MOPAR rnd K&N 14X3"aircleaner;headers, Flowmaster Super 40
Reply With Quote
  #9  
Old 03-04-2009, 01:07 AM
mcss8541's Avatar
mcss8541 mcss8541 is offline
All Star
 
Join Date: Feb 2007
Vehicle: 98 RAM 1500 4X4
Location: EL CAMPO, TX
Posts: 946
Default

Quote:
Originally Posted by Viper37 View Post
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.
Can someone tell me after what particular parts should I reset the pcm?
__________________
98 DODGE RAM 1500 SPORT 4X4 5.9L 6" LFT W/3" BODY LFT; PRO COMP WHEELS 8089 AND 35X12.5R17 DUNLOP RADIAL MUD ROVERS; CUSTOM FRONT BUMPER, Flex-a-lite dual electric fans , MOPAR rnd K&N 14X3"aircleaner;headers, Flowmaster Super 40
Reply With Quote
  #10  
Old 03-04-2009, 01:18 AM
Viper37 Viper37 is offline
Banned
 
Join Date: May 2008
Location: The Communist Puppet State of Mexifornia
Posts: 1,031
Default

Turn it to crank for fastest effect.

Anytime you do an air filter, change engine parts or something like that you reset the PCM.
Reply With Quote
  #11  
Old 03-04-2009, 01:22 AM
mcss8541's Avatar
mcss8541 mcss8541 is offline
All Star
 
Join Date: Feb 2007
Vehicle: 98 RAM 1500 4X4
Location: EL CAMPO, TX
Posts: 946
Default

Quote:
Originally Posted by Viper37 View Post
Turn it to crank for fastest effect.

Anytime you do an air filter, change engine parts or something like that you reset the PCM.
That's a Roger my friend will do. Now Do I have to drive X many miles at X MPH to reset it?
__________________
98 DODGE RAM 1500 SPORT 4X4 5.9L 6" LFT W/3" BODY LFT; PRO COMP WHEELS 8089 AND 35X12.5R17 DUNLOP RADIAL MUD ROVERS; CUSTOM FRONT BUMPER, Flex-a-lite dual electric fans , MOPAR rnd K&N 14X3"aircleaner;headers, Flowmaster Super 40
Reply With Quote
  #12  
Old 03-04-2009, 01:26 AM
Viper37 Viper37 is offline
Banned
 
Join Date: May 2008
Location: The Communist Puppet State of Mexifornia
Posts: 1,031
Default

It will reset very quickly. I wouldn't worry about it.
Reply With Quote
  #13  
Old 03-04-2009, 02:15 AM
mcss8541's Avatar
mcss8541 mcss8541 is offline
All Star
 
Join Date: Feb 2007
Vehicle: 98 RAM 1500 4X4
Location: EL CAMPO, TX
Posts: 946
Default

Quote:
Originally Posted by Viper37 View Post
It will reset very quickly. I wouldn't worry about it.
Thanks for your help.....now I have to find a zip tie for my TPS plug because the clip that locks it into place is broken and I'm having some stumbling issues on cold starts and now it's starting to do it on warm starts. The IAC valave is opening up to keep it from stalling.
__________________
98 DODGE RAM 1500 SPORT 4X4 5.9L 6" LFT W/3" BODY LFT; PRO COMP WHEELS 8089 AND 35X12.5R17 DUNLOP RADIAL MUD ROVERS; CUSTOM FRONT BUMPER, Flex-a-lite dual electric fans , MOPAR rnd K&N 14X3"aircleaner;headers, Flowmaster Super 40
Reply With Quote
  #14  
Old 03-04-2009, 09:00 AM
ron333's Avatar
ron333 ron333 is offline
Captain
 
Join Date: Mar 2004
Vehicle: '05 Ram 4x4 1500 HEMI 5.7L
Location: Plant City, FL
Posts: 554
Default

Ok, here's a different twist to this question.

Is there any way to get the PCM to readjust faster after it gets reset? It seems like it takes mine as much as 2 tanks of fuel sometimes before its performance becomes consistent. Before it has readjusted itself, the truck seems like it performs very differently each time I drive it. One time going for a drive it will seem to have extra pep and sensitive throttle response, then the next time I start it and go for a drive it seems to be less peppy and more sluggish than the last time. Shifts seem to happen at different rpms and different throttle positions, etc. until finally after as much as a couple of tank fulls of gas, the performance becomes consistent. Anybody else experience these conditions to this extent, or am I the only one?
__________________

2005 4wd 1500 HEMI, 4.56's, TruTrac, Mag-HyTec, 315/70-17 Hankook ATM's, Pacer rims, CAI, SC #3865, E-fan, 180* T-stat, PaceSetter Long Tubes with MagFlo cats & Spintech muffler - single exit hidden under bumper
Reply With Quote
  #15  
Old 03-04-2009, 09:13 AM
Silver_Dodge's Avatar
Silver_Dodge Silver_Dodge is offline
Grand Champion
 
Join Date: Nov 2004
Vehicle: 09 Ram/08 Aspen
Location: Colorado
Posts: 6,091
Default

I'm pretty sure it does clear any stored codes and CEL's, but I could be wrong. You don't need to do it for an air filter change unless you want to, but an air filter isn't going to make any performance difference. I would do it after install of any performance part like bored out TB, heads or rockers, cam, etc..., and after any tune-ups. You actually don't need to do it at all, it will eventually learn whatever it is you have put in. It's just more proactive this way.

The downside of doing it is that you will see a decline in your gas mileage for a little while. When the PCM is reset, it runs rich for some time. More in the beginning, then less as time goes on until it has everything dialed in.
__________________
2009 Ram 1500, 4x4, Hemi
1999 Ram R.I.P. - April 2008 Truck of the Month / January 2012 Ride of the Month / Dodge Forum 2012 Truck of the Year

Last edited by Silver_Dodge; 03-04-2009 at 09:28 AM..
Reply With Quote
  #16  
Old 03-04-2009, 11:20 AM
mcss8541's Avatar
mcss8541 mcss8541 is offline
All Star
 
Join Date: Feb 2007
Vehicle: 98 RAM 1500 4X4
Location: EL CAMPO, TX
Posts: 946
Default

Quote:
Originally Posted by ron333 View Post
Ok, here's a different twist to this question.

Is there any way to get the PCM to readjust faster after it gets reset? It seems like it takes mine as much as 2 tanks of fuel sometimes before its performance becomes consistent. Before it has readjusted itself, the truck seems like it performs very differently each time I drive it. One time going for a drive it will seem to have extra pep and sensitive throttle response, then the next time I start it and go for a drive it seems to be less peppy and more sluggish than the last time. Shifts seem to happen at different rpms and different throttle positions, etc. until finally after as much as a couple of tank fulls of gas, the performance becomes consistent. Anybody else experience these conditions to this extent, or am I the only one?
Dude you hit it right on the head. Mine does that but I haven't reset my PCM yet. But you are dead on. I haven't the foggiest idea of whats going on either.
__________________
98 DODGE RAM 1500 SPORT 4X4 5.9L 6" LFT W/3" BODY LFT; PRO COMP WHEELS 8089 AND 35X12.5R17 DUNLOP RADIAL MUD ROVERS; CUSTOM FRONT BUMPER, Flex-a-lite dual electric fans , MOPAR rnd K&N 14X3"aircleaner;headers, Flowmaster Super 40
Reply With Quote
  #17  
Old 03-04-2009, 11:23 AM
mcss8541's Avatar
mcss8541 mcss8541 is offline
All Star
 
Join Date: Feb 2007
Vehicle: 98 RAM 1500 4X4
Location: EL CAMPO, TX
Posts: 946
Default

Quote:
Originally Posted by Silver_Dodge View Post
I'm pretty sure it does clear any stored codes and CEL's, but I could be wrong. You don't need to do it for an air filter change unless you want to, but an air filter isn't going to make any performance difference. I would do it after install of any performance part like bored out TB, heads or rockers, cam, etc..., and after any tune-ups. You actually don't need to do it at all, it will eventually learn whatever it is you have put in. It's just more proactive this way.

The downside of doing it is that you will see a decline in your gas mileage for a little while. When the PCM is reset, it runs rich for some time. More in the beginning, then less as time goes on until it has everything dialed in.
Hey Silver I know this is kinda off topic but I notice you're running a Flowmaster Super 40 and a Magna Flow Cat, how's that working out for you? That's what I'm in the market for. Currently I have the original cat and a 5 ft section of 3" straight pipe that has split duals out back.
__________________
98 DODGE RAM 1500 SPORT 4X4 5.9L 6" LFT W/3" BODY LFT; PRO COMP WHEELS 8089 AND 35X12.5R17 DUNLOP RADIAL MUD ROVERS; CUSTOM FRONT BUMPER, Flex-a-lite dual electric fans , MOPAR rnd K&N 14X3"aircleaner;headers, Flowmaster Super 40
Reply With Quote
  #18  
Old 03-04-2009, 11:23 AM
Silver_Dodge's Avatar
Silver_Dodge Silver_Dodge is offline
Grand Champion
 
Join Date: Nov 2004
Vehicle: 09 Ram/08 Aspen
Location: Colorado
Posts: 6,091
Default

Welcome to speed density design. I notice mine takes anywhere from 200-400 miles before I feel like it is were it needs to be. On a mass air system, it seems like it happens a lot faster.
__________________
2009 Ram 1500, 4x4, Hemi
1999 Ram R.I.P. - April 2008 Truck of the Month / January 2012 Ride of the Month / Dodge Forum 2012 Truck of the Year
Reply With Quote
  #19  
Old 03-04-2009, 11:45 AM
mcss8541's Avatar
mcss8541 mcss8541 is offline
All Star
 
Join Date: Feb 2007
Vehicle: 98 RAM 1500 4X4
Location: EL CAMPO, TX
Posts: 946
Default

Quote:
Originally Posted by Silver_Dodge View Post
Welcome to speed density design. I notice mine takes anywhere from 200-400 miles before I feel like it is were it needs to be. On a mass air system, it seems like it happens a lot faster.
What's the difference between and speed density design engine nd a mass air? Also look at my previous response regarding you exhaust system.......unless you no longer have it.
__________________
98 DODGE RAM 1500 SPORT 4X4 5.9L 6" LFT W/3" BODY LFT; PRO COMP WHEELS 8089 AND 35X12.5R17 DUNLOP RADIAL MUD ROVERS; CUSTOM FRONT BUMPER, Flex-a-lite dual electric fans , MOPAR rnd K&N 14X3"aircleaner;headers, Flowmaster Super 40
Reply With Quote
  #20  
Old 03-04-2009, 12:13 PM
Silver_Dodge's Avatar
Silver_Dodge Silver_Dodge is offline
Grand Champion
 
Join Date: Nov 2004
Vehicle: 09 Ram/08 Aspen
Location: Colorado
Posts: 6,091
Default

It's complex when you start looking at open loop operations versus closed loop, but in a nut shell, speed density engines have no way to accurately measure the amount of incoming air into the cylinders. Speed density engines use a combination of readings from different sensors (namely o2) to give the PCM an idea of how much air is present. But it takes time because the algorithms used in the PCM require data collection over a period of time to so that it has confidence in the readings it is seeing. It is also not able to make changes that quickly either.
More modern Mass Air Flow (MAF/AFM) engines use a mass air sensor to give the computer that information real time, and it can therefore make changes to fuel and timing much quicker based on that information.
__________________
2009 Ram 1500, 4x4, Hemi
1999 Ram R.I.P. - April 2008 Truck of the Month / January 2012 Ride of the Month / Dodge Forum 2012 Truck of the Year
Reply With Quote
Old 03-04-2009, 12:13 PM
 
 
 
Reply




Tags
2003, 59, 98, caliber, caravan, dakota, dodge, fort, grand, hid, pcm, ram, reset, start, worth

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

Join DodgeForum
Advertising

Featured Sponsors
Vendor Directory
Our Sponsors
All times are GMT -4. The time now is 04:02 PM.

Internet Brands, Inc.


Contact Details & Emails