LMM: Lmm no start from key

quinton

Active member
Nov 28, 2011
1,883
0
36
Granbury Tx.
Messing with a lmm that will not start, no click or anything. Two
codes are p2510 and p2536. Another shop had it and said it would run then DLIS fuse would blow and wouldn’t start. Would replace the fuse and same thing would happen. Now no start period. New Tcm and ignition still nothing. Now I can start the truck from jumping the starter and it runs. Now I can pull the DLIS fuse and it still runs. Also when key is off the radio and windows still operate until the battery is disconnected. Any ideas?
 

Ron Nielson

Active member
Oct 11, 2009
766
144
43
Berryton, KS
You have proven that you have a short somewhere - the blowing fuse tells you that. Now, you just have to figure out where it is. Something is backfeeding voltage somewhere also. That may be harder to find.

Get a wiring diagram to help you understand what wires connect to what wires.
 

Tommyashley

New member
Dec 19, 2018
17
0
0
I found something one day and may not have anything to do with the issue,,, and hes right if fuse blows that means a short

anyways, I uploaded a efi tune one day and my truck wouldn't start or do anything,,, uploaded old tune back and presto,,,,,sorry might help someone in type situation
 

Blackmax123

Member
Aug 2, 2014
683
1
18
central Pennsylvania
I deleted the glow plug off my lmm and had my tunes updated. Thought I could remove the glow plug module. It wouldn't work with the key start or stop until the module was reinstalled.. just a thought. I'd also check the body control module.
 

gmduramax

Shits broke
Jun 12, 2008
4,076
250
83
Nor cal
I deleted the glow plug off my lmm and had my tunes updated. Thought I could remove the glow plug module. It wouldn't work with the key start or stop until the module was reinstalled.. just a thought. I'd also check the body control module.

It’s because the GPCM completes the circuit for the gmlan line. I could be wrong but it’s what I remember off the top of my head. You can locate the wires and connect them and remove the GLCM. Not sure if there’s a resistor that needs to be added. Do a search and you’ll find the thread.
 

clrussell

pro-procrastinator
Sep 23, 2013
5,928
399
83
Also I’ve seen the wires going to the start being shorted on the power steering pump. Blows the starter fuse when you go to crank it.

Completely different but semi the same.