Use high speed

[minytrker]

I was tuning a 04 2500HD with a 6.0 and the only way I could flash it is if I would uncheck the high speed box. It still flashed in about 30 secs but it would not flash unless I unchecked that box. Has anyone seen this before?

[SinisterSS]

Did it have OnStar?

[dc_justin]

I cannot flash my SS in high speed. I used to be able to, but for some reason no longer. If I try, it will go extremely slow, perhaps 1k every 3 seconds.
I also have problems doing a read flash with it. It will reset the gauge cluster 2 or 3 times while doing the read flash, acting like it is going to crash... It's not my PCM, something with the wiring, as I have had to slow flash 3 pcms using this wiring.

[Doc]

I recently tuned a 2005 HD 6.0L with no problems.

[minytrker]

Did it have OnStar?

I dont think it did

I cannot flash my SS in high speed. I used to be able to, but for some reason no longer. If I try, it will go extremely slow, perhaps 1k every 3 seconds.
I also have problems doing a read flash with it. It will reset the gauge cluster 2 or 3 times while doing the read flash, acting like it is going to crash... It's not my PCM, something with the wiring, as I have had to slow flash 3 pcms using this wiring.

yep thats exactly what it does

[dc_justin]

yep thats exactly what it does

I'm wanting to do a full flash to Custom OS3 soon on it, but I'm afraid that I'll get started and never be able to finish the flash...

[Alvin]

disconnect the battery first.. That really helps

[SinisterSS]

Are you guys running the latest tuning software? I flashed my SSS about 10 times the other day without any issues.

Justin, for a fellow SSS owner, send your PCM to me and I'll bench-flash COS3 for you - just cover shipping.

[minytrker]

To make you feel better, I had it lock up on me once during a normal flash and efi was able to recover it using the slower flash with no problem. I have another pcm here for that truck I am thinking about throwing it in just to see if its the truck or pcm.

[dc_justin]

To make you feel better, I had it lock up on me once during a normal flash and efi was able to recover it using the slower flash with no problem. I have another pcm here for that truck I am thinking about throwing it in just to see if its the truck or pcm.

I've had mine fail on MANY times during a partial flash, both with my truck, and when I've put in 2 other PCMs to tune them, both have had the same issues.