LMM Duramax from hell!!!

LBZ_Baker98

Member
Jul 8, 2016
207
2
18
Texas
I know it will burn something. That's honestly the point I'm at. If it burns the wire I'll be able to find what's wrong :roflmao:
 

battlegraduate09

Gearhead
Mar 18, 2010
610
0
16
been stated, alldata.com should have them. Did you ever marry the bcm with the modules, you can do it without a tech 2 there is a process if you google it.I cant recall the exact method off top of my head but i done it on my 04 and it worked.
 

LBZ_Baker98

Member
Jul 8, 2016
207
2
18
Texas
I just found the relearn procedure but I don't think it will work because it will blow the fuse as soon as you turn the key on. I may be wrong though:confused:
 

2004LB7

Well-known member
Dec 15, 2010
6,372
1,733
113
Norcal
Turn on the ignition, don't attempt to start the truck, wait for the security light to go off. Usually its about 10 minutes. Turn off ignition. Do this three times. On the last time the ecm and bcm should now be happy being in each others company and should allow the engine to start
 

LBZ_Baker98

Member
Jul 8, 2016
207
2
18
Texas
Turn on the ignition, don't attempt to start the truck, wait for the security light to go off. Usually its about 10 minutes. Turn off ignition. Do this three times. On the last time the ecm and bcm should now be happy being in each others company and should allow the engine to start

Okay will try it in the morning and then update. Thank you to everyone for the suggestions. They are more then appreciated!
 

LBZ_Baker98

Member
Jul 8, 2016
207
2
18
Texas
Traced all the wires and couldn't find anything wrong with any of them. Yesterday the key would kill all power like it's supposed to. Now it's back to the dash lights and cablights etc etc staying on after turning key off. The 2 amp DLIS fuse also quit blowing but truck still won't start. I'm at my wit's end.
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,314
1,601
113
Mid Michigan
Traced all the wires and couldn't find anything wrong with any of them. Yesterday the key would kill all power like it's supposed to. Now it's back to the dash lights and cablights etc etc staying on after turning key off. The 2 amp DLIS fuse also quit blowing but truck still won't start. I'm at my wit's end.
You can't base wiring condition simply on looks. The leads within the casing could be broken, and you'd never know it from the outside. You'll have to check continuity through the individual circuits.
 

2004LB7

Well-known member
Dec 15, 2010
6,372
1,733
113
Norcal
Almost sounds to me that something is shorting out the BCM and possibly killing it too. You may need to check all of the circuits coming out of the BCM that the DLS fuse powers.

What about putting a light bulb in line with the fuse? Something that will limit the current to a safe level then probe the wires and measure the voltage. When you remove the short or disconnect the bad wire the bulb will drop in brightness or go out.
 

LBZ_Baker98

Member
Jul 8, 2016
207
2
18
Texas
I'll get the light bulb rigged up tomorrow. This has been a going on for almost 2 months. 2 shops have already looked at it and gave up. I'm ready to call it quits but so determined at the same time!:mad:
 

LBZ_Baker98

Member
Jul 8, 2016
207
2
18
Texas
Just to update everyone. I have put hours on hours into this thing and I'm finally calling it quits. It's going to another shop on Monday that has even agreed to let me shadow the mechanic while he diags and hopefully fixes it. I'll update everyone with the fix. Thank you to everyone who has helped:beer2: