ECM vs. PCM vs. ECU? - LS1TECH



PCM Diagnostics & Tuning HP Tuners | AutoTap | Diablo | MAF Translator | HPP3 | FAST | Gen7 | Big Stuff 3
Sponsored by:
Sponsored by:

ECM vs. PCM vs. ECU?

Reply
 
Thread Tools Search this Thread
Old 02-06-2010, 10:34 AM   #1
TECH Enthusiast
Thread Starter
iTrader: (1)
 
Join Date: Feb 2007
Location: FL Gulf Coast
Posts: 667
Default ECM vs. PCM vs. ECU?

What are the actual differences between an Engine Control Module, Powertrain Control Module and Engine Control Unit?

Thanks.

Tipsy
TipsyMcStagger is online now   Reply With Quote
Old 02-06-2010, 10:41 AM   #2
LS1Tech Platinum Sponsor
 
06MonteSS's Avatar
 
Join Date: Dec 2005
Location: CT
Posts: 2,873
Default

ECM - engine control module... controls only the engine... so it is also accompanied by a TCM - transmission control module, to control tranny settings... GM went to this separate setup starting around 2005 in certain vehicles, then more widely used in 2006 vehicles, and now is the norm on all new vehicles...

PCM - powertrain control module - a single control module that contains all the settings/programming for BOTH the engine and the transmission...

ECU - engine control unit - just a term that can be used to describe either an ECM or a PCM...
06MonteSS is offline   Reply With Quote
Old 02-06-2010, 10:46 AM   #3
TECH Enthusiast
Thread Starter
iTrader: (1)
 
Join Date: Feb 2007
Location: FL Gulf Coast
Posts: 667
Default

Thanks for the breakdown.

Stupid question but is a TCM required if using an ECM and a T56?

Tipsy
TipsyMcStagger is online now   Reply With Quote
Old 02-06-2010, 10:50 AM   #4
LS1Tech Platinum Sponsor
 
06MonteSS's Avatar
 
Join Date: Dec 2005
Location: CT
Posts: 2,873
Default

what vehicle? what engine? which model ECM - i.e. e38, e40, e67, etc etc??
06MonteSS is offline   Reply With Quote
Old 02-06-2010, 10:56 AM   #5
TECH Enthusiast
Thread Starter
iTrader: (1)
 
Join Date: Feb 2007
Location: FL Gulf Coast
Posts: 667
Default

Quote:
Originally Posted by 06MonteSS View Post
what vehicle? what engine? which model ECM - i.e. e38, e40, e67, etc etc??
I'm just in the hypothetical stage right now. Plan to install an LQ4 and a T56 into a Fox body Mustang.

I have no parts yet. Just collecting knowledge.

Tipsy
TipsyMcStagger is online now   Reply With Quote
Old 02-06-2010, 11:36 AM   #6
TECH Fanatic
iTrader: (10)
 
eseibel67's Avatar
 
Join Date: Feb 2008
Location: Kitchener, ON
Posts: 1,749
Default

Quote:
Originally Posted by TipsyMcStagger View Post
Thanks for the breakdown.

Stupid question but is a TCM required if using an ECM and a T56?

Tipsy
No, controller is still called a PCM even on T56 cars.

LS1 autos also use PCM, no TCM.
eseibel67 is offline   Reply With Quote
Old 02-06-2010, 12:10 PM   #7
LS1Tech Platinum Sponsor
 
06MonteSS's Avatar
 
Join Date: Dec 2005
Location: CT
Posts: 2,873
Default

no, you would not need a separate TCM for that tranny setup... just the ECM for the engine....
06MonteSS is offline   Reply With Quote
Old 02-06-2010, 12:23 PM   #8
TECH Enthusiast
Thread Starter
iTrader: (1)
 
Join Date: Feb 2007
Location: FL Gulf Coast
Posts: 667
Default

Quote:
Originally Posted by 06MonteSS View Post
no, you would not need a separate TCM for that tranny setup... just the ECM for the engine....
Okay...thanks. But based on the age of the average LQ4, wouldn't it be a PCM?

I'm just a bit unsure because you wrote previously with regard to ECM's that "GM went to this separate setup starting around 2005 in certain vehicles, then more widely used in 2006 vehicles, and now is the norm on all new vehicles."

I'm not sure if the LQ4 is still in production but if it is, I'd assume the newer engines had an ECM (with a TCM) and the older (pre-2005?) vehicles had PCM's?

Sorry if I'm mincing terms...I'm just trying to gain some clarity.

Tipsy
TipsyMcStagger is online now   Reply With Quote
Old 02-06-2010, 01:04 PM   #9
LS1Tech Platinum Sponsor
 
06MonteSS's Avatar
 
Join Date: Dec 2005
Location: CT
Posts: 2,873
Default

if it's an older Lq4, that used a single PCM, then you'd need to get the tranny parameters in it disabled, since you're pairing it up with a non-stock tranny setup/combo...

if it's a newer lq4, that uses an ECM/TCM combo, then you just need to use the ECM for the engine...
06MonteSS is offline   Reply With Quote
Old 02-06-2010, 01:07 PM   #10
TECH Enthusiast
Thread Starter
iTrader: (1)
 
Join Date: Feb 2007
Location: FL Gulf Coast
Posts: 667
Default

Quote:
Originally Posted by 06MonteSS View Post
if it's an older Lq4, that used a single PCM, then you'd need to get the tranny parameters in it disabled, since you're pairing it up with a non-stock tranny setup/combo...

if it's a newer lq4, that uses an ECM/TCM combo, then you just need to use the ECM for the engine...
Makes perfect sense.

Thanks!

Tipsy
TipsyMcStagger is online now   Reply With Quote
Old 04-17-2010, 03:09 PM   #11
Teching In
 
Join Date: Nov 2009
Posts: 1
Default

so if i have an lq4 in my truck (2004 2500hd lq4 4l80e) it has pcm i believe. ive read some people have use some OE parts that utilize a cable style throttle body. Also i have read that i can tune my pcm to remove all the torque management. i need help understanding all these things and what the best route would be to extract the most power the is being restricted from my lq4.....

Thanks,
Nick
Bad2500HD is offline   Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Custom Comp cam 224/236 .609/.607 108+3 boardslide Parts Classifieds 4 04-06-2012 06:51 AM
just had to share this 67camarors Northwest Members 7 03-29-2009 01:59 AM
Bright Green Trans Am Ws6 OMG!! 1996firebirdformula Racer's Lounge 43 01-30-2009 06:10 PM
Car Show Sunday April 6th New Brunswick Nj JETNITRO Eastern Members 60 04-09-2008 01:49 PM
Gto Vs Corvette Battle @ Atco Raceway N.J JETNITRO Other Special Events 4 03-08-2008 11:22 PM


Tags
body, controller, difference, e67, ecm, ecmpcm, ecu, engine, fox, info, location, lq4, ls1, number, pcm, vs

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 On
Refbacks are Off



All times are GMT -5. The time now is 04:14 PM.