Did I brick my PCM? OS Swap from 12619623 to 12587811

[cabech984]

Hi all,

I have a 2006 Silverado 1500 RCSB 2WD with a L59 5.3L with cam and long tubes and now a junkyard stock 4L80e from a early 2000's 2500HD that I threw in place of the 4L60e I fried. I thought I was going to be doing a straightforward segment swap, so I spliced in input speed sensor wiring from the pcm to the transmission and instead of re-pinning the transmission connector, I bought a cheap adapter connector. I fired it up yesterday on the 4L60e tune to verify fluid level and reverse and drive engagement, both of which worked. After that, I began looking for a good stock 4L80e file to proceed with the segment swap. I discovered that my OS # 12619623 was never used with a 4L80e transmission. Instead of buying the conversion adapter harness, I decided to search for a 2006 year tune file featuring a stock 4L80e and found one using OS # 12587811 from the tune repository, which I believe is from a 1500HD. I copied my engine tune data over and left the transmission tables alone. I flashed the file over to the PCM. I went into the change VIN wizard and put my truck's vin in it, flashed it again. I tried starting the truck and was greeted with "Reduced engine power" displayed on the DIC, and no crank, no start conditions. Also noticed that the PRNDL doesn't switch positions when moving thru the gear range. I was able to connect to VCM scanner and check for codes and found the following:

P0606
P0622
P1631
U0107

To top it off, now when I try reading/writing to the PCM, it wont allow me to read/write and I'm greeted with the following message: Download boot loaded: Request download x7F Negative response code.

Should I have done a VATS relearn to the truck after changing OS? That's the only thing I didn't think of before shutting down the shop for the night.

I've been trying to search info on what I have going on but haven't had much luck, so figured I'd post before pulling anymore hair out of my head! Thanks


4L80e swap OS with L59 Engine Tune.hpt

[blindsquirrel]

Does your PCM Service Number match the one that fits the tune file you tried to use?

[cabech984]

Does your PCM Service Number match the one that fits the tune file you tried to use?

Dumb question, where would I find the service number? In HP tuners or physically on the pcm?

[blindsquirrel]

On the sticker. Then look up what Service Number fits according to your VIN, make sure it's got the right one in it to start with. Then look up what Service Number the VIN from your repository file uses.

Nowhere does anybody officially recommend using HP Tuners to change operating systems like this, as a replacement for a real programming tool and GM SPS. And if somebody unofficially recommends doing it, they're going against what the people who made the tool & software say.

[cabech984]

On the sticker. Then look up what Service Number fits according to your VIN, make sure it's got the right one in it to start with. Then look up what Service Number the VIN from your repository file uses.

Nowhere does anybody officially recommend using HP Tuners to change operating systems like this, as a replacement for a real programming tool and GM SPS. And if somebody unofficially recommends doing it, they're going against what the people who made the tool & software say.

My PCM's service number is 12602802 which appears to interchange with the file I pulled from the repository. I'm not sure how to be 100% sure on that end though aside from cross referencing part numbers for the year of truck

[2xLS1]

Did you write calibration or write entire the new file?

[cabech984]

Did you write calibration or write entire the new file?

Write Entire

[cabech984]

I have a feeling that copying my truck's data for the Electronic throttle control over to the new OS may have bricked the pcm. The DTC's along with the 'Request download x7F Negative response code" seem to come up in alot of searches regarding bricked PCM's. I think I'll just locate another PCM and have it flashed to my truck and buy the harness that allows me to keep the 4L60e calibration

[Shrek]

... I have a feeling that copying my truck's data for the Electronic throttle control over to the new OS may have bricked the pcm ...

That is a strong possibility.

The 12619623 and 12587811 operating systems are interchangeable for the purposes of your project and P59 PCM.

With a DBW system, and a P59 PCM, it is NOT advisable to change any of the ETC (Electronic Throttle Control) tables - unless you are a very experienced tuner. All Trucks from that era used the same DBW Throttle Body - so leave the base ETC programming in the OS untouched.

My two cents ... it is much more straight forward to run 4L80 segments in the PCM, than it is to purchase an adapter harness, and then "tune around" the transmission differences.

[cabech984]

With a DBW system, and a P59 PCM, it is NOT advisable to change any of the ETC (Electronic Throttle Control) tables - unless you are a very experienced tuner. All Trucks from that era used the same DBW Throttle Body - so leave the base ETC programming in the OS untouched.

Gotcha, so leave the Programming in the NEW OS alone? I found a followthru and video about grounding a solder point in the pcm while bench flashing that might help reset the pcm to a useable state. I'm going to give it a try in a couple days and see what happens

[Shrek]

In the new OS just do not touch any tables related to the ETC (Electronic Throttle Control).

From the old OS you can copy over any other parameter that you deem to be necessary - VE table, MAF table, injector flow characteristics, the list goes on.

[cabech984]

In the new OS just do not touch any tables related to the ETC (Electronic Throttle Control).

From the old OS you can copy over any other parameter that you deem to be necessary - VE table, MAF table, injector flow characteristics, the list goes on.

Okay thanks, well I'll try to unbrick this pcm and give that a shot! Thanks alot

[cabech984]

That is a strong possibility.

The 12619623 and 12587811 operating systems are interchangeable for the purposes of your project and P59 PCM.

With a DBW system, and a P59 PCM, it is NOT advisable to change any of the ETC (Electronic Throttle Control) tables - unless you are a very experienced tuner. All Trucks from that era used the same DBW Throttle Body - so leave the base ETC programming in the OS untouched.

My two cents ... it is much more straight forward to run 4L80 segments in the PCM, than it is to purchase an adapter harness, and then "tune around" the transmission differences.

I did what you suggested and turned the ETC tables back to the 12587811 OS settings. I put the PCM on a bench harness, grounded one of the solder points on the circuit board, and wrote the new calibration over to the PCM. Put the PCM back in the truck, did a vats re-link, and vin change to my VIN, and the truck fired right up. The alternator output DTC's were just being reported where in my OEM tuning, they were labeled "No Error Reported", so I changed them to that. All seems well!

Thanks for the guidance! Time to start tuning again, this thing doesn't want to idle!