Need Help, '03 Won't Start

[lcaad1249]

I started working on a truck for a local guy. The truck looks like it had a programmer on it. I pulled the file sent it to be modded, and got a clean file to flash back in the truck.

When I start to flash the truck my EFI unit won't connect. On V7 it was unable to get status and I can't remember the error on V8. It did try start to flash using V8 after the 5th (ish) time, and the truck wouldn't start.

My programmer and I both thought the ECM was bad. So I got a new one that was checked and flashed with the EFI program to go on the truck while on the bench.

The new ECM changed nothing. It still won't start. I've checked the fuses under the hood and in the dash but they're all good. I also jumpered the starter and while bypassing, it cranked but wouldn't start the truck even with the key on.

I'm sending the original ECM to the programmer tomorrow to see if that really was the problem.

Also with my EFI unit connected the V8 autodetects the PCM but not the ECM.

Any thoughts, suggestions, things to try?? Any help is appreciated!!

[lcaad1249]

ttt

[lcaad1249]

Any ideas?

[Duramax 6.6L]

Are there any codes available?

[lcaad1249]

Can't connect to the truck. V8 only see the PCM not ECM. In 7.5, I select LB7, it goes to Flashscan/autocal Only and will not give me the option to Display codes.

[Duramax 6.6L]

Have you tried to connect with an every day code reader and an scan tool?

[GMPX]

It sounds like the flash never really started.
Try pulling the batteries for 30 seconds or so, then see if the truck will run. But, I suspect there is probably something on the truck wired in to the data bus causing your issues. Aftermarket stereo, XM Radio adaptors, iPod adaptors that are also wired in to the data bus are renowned for causing reflash problems.

[Duramax 6.6L]

It sounds like the flash never really started.
Try pulling the batteries for 30 seconds or so, then see if the truck will run. But, I suspect there is probably something on the truck wired in to the data bus causing your issues. Aftermarket stereo, XM Radio adaptors, iPod adaptors that are also wired in to the data bus are renowned for causing reflash problems.
What doesn't make sence is that he put a bench programmed ecm in the truck, This might be a security problem,

[lcaad1249]

The programmer said that security had been turned off on the new ecm/program. Any ideas what to try for a security problem?

I've had the batteries disconnected for minutes multiple times.

Thanks for all the help!!

[lcaad1249]

Bump, any other things to look for / try?

[lcaad1249]

The programmer got the first ECM today and it had no communication. They were flashing a 3rd ECM to send and try and noticed an error. From what I could understand you can't do a complete flash from scratch using EFI so he flashed using a Tech 2 and then with EFI. Should be in Wednesday to try.

[lcaad1249]

Got the ECM that was flashed correctly on last night and it fired right up. Thanks for the help.