PCM will not accept a tune and kills PCM. - LS1TECH - Camaro and Firebird Forum Discussion

Notices
PCM Diagnostics & Tuning HP Tuners | Diablo | Pantera EFI
Sponsored by:
Sponsored by:

PCM will not accept a tune and kills PCM.

Old 01-04-2019, 09:14 PM
  #1  
Registered User
Thread Starter
 
Join Date: Jan 2019
Posts: 7
Default PCM will not accept a tune and kills PCM.

No Camaro but I do have a 6.0 Hummer H2 and thought someone here might be able to help. Seems to be a pretty active tuning forum.

Just before Thanksgiving I took my 2005 Hummer H2 into a very reputable shop for some repairs, mods, and a full dyno tune.

Engine is a 6.0 with headers/full exhaust, Trailerblazer SS intake and 90mm TB.



The maintenance and mods were completed in a day and then the trouble started.

I had previously obtained a tune based on some mods from Blackbear Performance. When this shop attempted to connect to my ECM it "died". They thought it was just a bad ECM and got another. They installed it and the same thing happened. When they connected it killed the ECM.

I have talked to several shops as have they. The consensus is that a module is communicating at the same time which will kill the ECM. They have disabled everything they can and the problem persists. Onstar, Stereo, something about the transfer case module was suggested, etc. etc.



If anyone has experienced something like this and has input I would greatly appreciate it.

Mr. Demeanor is offline  
Old 01-04-2019, 10:47 PM
  #2  
TECH Addict
iTrader: (2)
 
gofastwclass's Avatar
 
Join Date: Aug 2009
Location: KCMO
Posts: 2,793
Default

I've experienced this on full size trucks / SUV's with aftermarket alarms and / or stereos and it's a known issue. I would think a Hummer would be in similar territory. Do you have an aftermarket stereo or alarm system installed? If so, do you have the door chime or radio interface for stereo controls on the wheel? Get rid of them and try again. If that is the case the PCM isn't dead, it just won't fully read / flash properly. If you are using HP Tuners it should be able to recover the PCM once the problem is cleared. I bench flashed one guys PCM until I figured out what was causing all the drama.
gofastwclass is offline  
Old 01-05-2019, 09:39 AM
  #3  
Registered User
Thread Starter
 
Join Date: Jan 2019
Posts: 7
Default

Originally Posted by gofastwclass View Post
I've experienced this on full size trucks / SUV's with aftermarket alarms and / or stereos and it's a known issue. I would think a Hummer would be in similar territory. Do you have an aftermarket stereo or alarm system installed? If so, do you have the door chime or radio interface for stereo controls on the wheel? Get rid of them and try again. If that is the case the PCM isn't dead, it just won't fully read / flash properly. If you are using HP Tuners it should be able to recover the PCM once the problem is cleared. I bench flashed one guys PCM until I figured out what was causing all the drama.
Aftermarket stereo has been disabled according to the shop. No alarm or other aftermarket device.
Mr. Demeanor is offline  
Old 01-05-2019, 12:29 PM
  #4  
Registered User
Thread Starter
 
Join Date: Jan 2019
Posts: 7
Default

I was just thinking the stereo has a separate module for the door chime and steering wheel controls I believe. The said they pulled all the fuses for the stereo but could that device be on a separate circuit?
Mr. Demeanor is offline  
Old 01-06-2019, 10:07 AM
  #5  
TECH Addict
iTrader: (2)
 
gofastwclass's Avatar
 
Join Date: Aug 2009
Location: KCMO
Posts: 2,793
Default

When I said "get rid of them" I wasn't referring to pulling the fuse, I was serious. Get rid of them. Get them COMPLETELY out of the circuit. I don't care if you re-install them later (I'm not a music guy so that stuff ends up in the trash if I buy a car with it) but as long as you are tuning they need to be gone.

Years ago I wasted way too much time trying to tune a guys truck that had a bunch of aftermarket radio crap and there were only two things that worked: removing and bench flashing the PCM (sucks) and removing the connectors to his aftermarket radio junk. The first time I ran into this I probably burned an hour or more more playing with fuses and troubleshooting other stuff (besides thinking my stuff was broken) before I did what I should have done in the first place. I pulled the radio bezel off and disconnected every bit of aftermarket radio wizardry under the dash. Afterward I reconnected my interface and flashed a new cal in record time. Now I don't even waste time or take a chance I just disable the junk first and save us both a lot of agony.
gofastwclass is offline  
Old 01-06-2019, 11:55 AM
  #6  
TECH Veteran
iTrader: (21)
 
truckdoug's Avatar
 
Join Date: Nov 2013
Location: Portlandia
Posts: 4,427
Default

I had a bad install on a remote start do the same thing once. so frustrating. of course the dingdong customer was like "it worked fine before I brought it to you"

truckdoug is online now  
Old 01-06-2019, 11:16 PM
  #7  
Registered User
Thread Starter
 
Join Date: Jan 2019
Posts: 7
Default

Originally Posted by gofastwclass View Post
When I said "get rid of them" I wasn't referring to pulling the fuse, I was serious. Get rid of them. Get them COMPLETELY out of the circuit. I don't care if you re-install them later (I'm not a music guy so that stuff ends up in the trash if I buy a car with it) but as long as you are tuning they need to be gone.

Years ago I wasted way too much time trying to tune a guys truck that had a bunch of aftermarket radio crap and there were only two things that worked: removing and bench flashing the PCM (sucks) and removing the connectors to his aftermarket radio junk. The first time I ran into this I probably burned an hour or more more playing with fuses and troubleshooting other stuff (besides thinking my stuff was broken) before I did what I should have done in the first place. I pulled the radio bezel off and disconnected every bit of aftermarket radio wizardry under the dash. Afterward I reconnected my interface and flashed a new cal in record time. Now I don't even waste time or take a chance I just disable the junk first and save us both a lot of agony.

Ill talk to the shop. Thanks. Monday is 9 weeks.....
Mr. Demeanor is offline  
Old 01-07-2019, 02:57 PM
  #8  
10 Second Club
iTrader: (3)
 
MontecarloDrag's Avatar
 
Join Date: Aug 2005
Posts: 873
Default

Don't over complicate things. If pulling radio and onstar fuses doesn't solve the issue, just unplug the ECU and flash it on a bench harness.
A bad battery is a more likely cause than anything else.
MontecarloDrag is online now  
Old 01-07-2019, 09:42 PM
  #9  
Registered User
Thread Starter
 
Join Date: Jan 2019
Posts: 7
Default

Originally Posted by MontecarloDrag View Post
Don't over complicate things. If pulling radio and onstar fuses doesn't solve the issue, just unplug the ECU and flash it on a bench harness.
A bad battery is a more likely cause than anything else.
Unfortunately they dont have a bench flash.
I believe tomorrow or hopefully soon they are pulling the dash off and disconnecting the stereo and door chime/steering wheel adapter.
Mr. Demeanor is offline  
Old 01-07-2019, 10:27 PM
  #10  
TECH Fanatic
iTrader: (32)
 
brandon6.0's Avatar
 
Join Date: Dec 2009
Location: Glennville, GA.
Posts: 1,921
Default

Steering wheel adapter will do it. Had a similar issue once. It will need to be unplugged completely. Cant just pull the fuse. Like said best thing would be to bench tune it.
brandon6.0 is online now  
Old 01-08-2019, 10:35 AM
  #11  
LS1Tech Sponsor
iTrader: (4)
 
LSX Power Tuning's Avatar
 
Join Date: Mar 2013
Location: Brenham TX
Posts: 2,090
Default

There are 6 fuses you need to pull.
__________________

Full Service LSX Shop
*MAIL ORDER TUNING LINK*
HP Tuners, EFI Live, SCT, Holley, BS3, FAST XFI
Holley Certified Installer & Tuner
MSD, Brian Tooley, HP Tuners, EFI Live, Holley, Edge, Superchips +100's more

Email, Remote, Mail Order, Dyno, Street & Track Tuning
*WEBPAGE* *FACEBOOK* *ONLINE STORE*
LSX Power Tuning is online now  
Old 01-08-2019, 11:56 AM
  #12  
Registered User
Thread Starter
 
Join Date: Jan 2019
Posts: 7
Default

Originally Posted by LSX Power Tuning View Post
There are 6 fuses you need to pull.
I would assume they know which ones but if you care to elaborate I am all ears.
Mr. Demeanor is offline  
Old 01-08-2019, 01:15 PM
  #13  
LS1Tech Sponsor
iTrader: (4)
 
LSX Power Tuning's Avatar
 
Join Date: Mar 2013
Location: Brenham TX
Posts: 2,090
Default

tbc
batt
tbc
ign1
radio
info
__________________

Full Service LSX Shop
*MAIL ORDER TUNING LINK*
HP Tuners, EFI Live, SCT, Holley, BS3, FAST XFI
Holley Certified Installer & Tuner
MSD, Brian Tooley, HP Tuners, EFI Live, Holley, Edge, Superchips +100's more

Email, Remote, Mail Order, Dyno, Street & Track Tuning
*WEBPAGE* *FACEBOOK* *ONLINE STORE*
LSX Power Tuning is online now  
Old 01-09-2019, 01:37 PM
  #14  
Registered User
Thread Starter
 
Join Date: Jan 2019
Posts: 7
Default

Originally Posted by LSX Power Tuning View Post
tbc
batt
tbc
ign1
radio
info
Thank you.
Mr. Demeanor is offline  
Old Today, 07:04 PM
  #15  
TECH Apprentice
iTrader: (3)
 
epfatboy's Avatar
 
Join Date: Oct 2013
Posts: 315
Default

How did this turn out?
epfatboy is offline  


Thread Tools
Search this Thread

About Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2018 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: