LMM wont crank

[timbo__7]

I installed a DSP5 switch and after getting done i go to start the truck and it started and everything seemed to be fine so I shut it off and start to button everything back up and after i got done with that i go to take a spin to make sure everything is working fine and go to start and it wont crank and my theft deterrent system light displays, so then i try to reflash my ecm and put my tunes on thinking this will disable the security but everytime i get to where the ecm is trying to delete the ecm flash memory the doors unlock and my abs and brake light come on (which might be normal i cant remember) and it wont finish flashing this is as far as it goes

14:14:18.368: Scanning for EFILive FlashScan V2 USB
14:14:18.381: Autodetect interface ...
14:14:20.184: Interface not detected
14:14:20.820: Scanning for EFILive FlashScan V2 HAPI
14:14:20.833: Autodetect interface ...
14:14:21.113: Interface firmware version: 2.7.12
14:14:21.117: Connection to [FSV2] interface is OK
14:14:21.338: USB driver version: 4.0.0
14:14:21.342: USB library version: 3.1.18
14:14:21.365: Interface firmware model: FSV2
14:14:21.411: Interface firmware model: FSV2
14:14:21.433: Interface firmware version: 2.7.12
14:14:21.459: Interface firmware date: Jun 06, 2011
14:14:21.484: FlashScan serial number: 003700734614
14:14:21.506: FlashScan license number: 003700734614
14:14:21.534: Disconnecting ...
14:14:22.096: CAN-VPW Bridge Deactivated
14:14:22.101: Disconnected
14:14:22.734: Scanning for EFILive FlashScan V2 USB
14:14:22.749: Autodetect interface ...
14:14:24.555: Interface not detected
14:14:25.191: Scanning for EFILive FlashScan V2 HAPI
14:14:25.206: Autodetect interface ...
14:14:25.492: Interface firmware version: 2.7.12
14:14:25.497: Connection to [FSV2] interface is OK
14:14:25.520: CAN-VPW Bridge Activated
14:14:25.595: Current protocol set to: "ISO 15765 CAN"
14:14:25.599: Autodetect ECM...
14:14:25.627: Connection to ECM is OK
14:14:25.653: Current protocol: "ISO 15765 CAN"
14:14:25.879: USB driver version: 4.0.0
14:14:25.883: USB library version: 3.1.18
14:14:25.907: Interface firmware model: FSV2
14:14:25.931: Interface firmware model: FSV2
14:14:25.958: Interface firmware version: 2.7.12
14:14:25.982: Interface firmware date: Jun 06, 2011
14:14:26.006: FlashScan serial number: 003700734614
14:14:26.030: FlashScan license number: 003700734614
14:14:26.298: Getting status...
14:14:26.534: Status: OK.
14:14:27.465: Preparing ECM for reflash...
14:14:27.492: ECM seed is: $E7CE
14:14:27.496: Unlock attempt 1 of 1
14:14:27.623: Initializing ECM...
14:14:29.080: Request serial number...
14:14:29.923: Serial number: 864724103330
14:14:32.353: Reflashing ECM's memory...
14:14:37.887: Erasing ECM flash memory... (please wait up to 2 minutes)
14:14:40.922: Waiting 1 of a possible 120...
14:14:41.926: Waiting 2 of a possible 120...
14:14:42.930: Waiting 3 of a possible 120...

...

14:16:39.427: Waiting 119 of a possible 120...
14:16:40.431: Waiting 120 of a possible 120...
14:17:03.748: ECM flash memory erased OK
14:17:15.979: Retrying previous block...
14:17:16.981: Erasing ECM flash memory... (please wait up to 2 minutes)
14:17:20.019: Waiting 1 of a possible 120...
14:17:21.023: Waiting 2 of a possible 120...
14:17:22.027: Waiting 3 of a possible 120...

and so on and so on

any thoughts would be great on how to fix this or does it sound like I need a new ecm i have no clue at this point I checked all fuses and they are good and software and firmware are up to date thanks

[8100 Power]

Go back to your harness and make sure all pins are intact in the connector, I'm betting you pulled something loose?

[timbo__7]

Ill check that again but the truck did start after the DSP was installed so i dont believe it is that

[timbo__7]

I went over all connections i could and everything looks good, I also looked over the Fuse Block and everything looked good there too, so I'm still at a loss of what it wrong. It just seems like the computer is locking me out from reflashing and i think it does it at this point below

14:14:27.623: Initializing ECM...
14:14:29.080: Request serial number...
14:14:29.923: Serial number: 864724103330
14:14:32.353: Reflashing ECM's memory...

Doors unlock and the brake light and abs light turn on and the door bell goes off for awhile

14:14:37.887: Erasing ECM flash memory... (please wait up to 2 minutes)
14:14:40.922: Waiting 1 of a possible 120...


After i shut down the efi when I realize it isnt going to reflash i'll try the process over again but If the brake and abs light is still on then i cant connect to the ecm until I cycle the key till the lights go out so thats why I think the ecm is locking me out from flashing, Could my TCM be bad too and cause these conditions im just trying to cover my bases before i have to haul it to the dealer which is my last option

[schwoch1]

I don't know if this will help you or not, but I just flashed a Trailblazer PCM the other day, and after the flash, it would not start or do anything, it was just dead, EFI Live would not talk to it (and tried several other programs also!).
Finally as a last ditch effort, I unplugged all the connectors off the PCM, let it sit for a few minutes, plugged them all back in and the PCM worked with no problems. I will say it scared the shit outa me when the customer is waiting for their truck and you can't make it start after a flash
Hope this helps!!
Mike

[timbo__7]

Nope I can get EFI to talk to the ecm and I can read the tune and I have had everything diconnected and I always get back to the same spot as stated above

[GMPX]

Prior to fitting the switch, had you been able to reflash the truck ok?

[8100 Power]

Nope I can get EFI to talk to the ecm and I can read the tune and I have had everything diconnected and I always get back to the same spot as stated above

I had a no start on my fathers LMM. I called Rob and like he told me to leave both batteries unplugged for about an hour to reset the computer then so in the scan tool and try to connect(push the green button). If it connects fine, disconnect and then full flash the stock tune in the ECM.

[timbo__7]

Yes I have been running Nicks 400 hp tune for a couple weeks so I have been able to flash the ecm before but now i cant for some reason, and I have disconnected the batterys more than once (for up too 24 hours) thinking that would fix the problem and that didnt either, I can connect to the ecm and tcm which confuses me on what the problem is I'm thinking it has to be something stupid but its not registering in my head right now what it could be, I've tried just about everything I can think of getting really close to sending it to the dealer but dont want too spend money on things they are gonna replace that dont need to be replaced and the labor on top of that

[GMPX]

Are you near anyone that might have a bench harness? It shouldn't make any difference on an LBZ / LMM, but maybe the ECM needs to be brought back to life outside of the vehicle.