Bricked it. My story...

[Chewy72ss]

UPDATE! Read post #10 for my solution.

First time using HPTuners, and everything has been going great, so far. Was able to get my 2003 5.3 L59, using a P59 ECM, all set up to run a 4l80e, dual e-fans, and F-body style A/C request. The only issue I had left, was the over-responsive gas pedal.

The swap is in a '92 Sonoma, and a long throw, non-adjustable pedal was modified quite a bit to fit in the stock location. However, at "70%" pedal position, I was at 100% TPS. Another odd part, is that the pedal position will read all the way to 150%. So, basically half pedal, it's WOT.

Through some digging, I found pepole with the same issue, having luck switching to an '06 OS.

Possibly a noob oversight, I found an '06 calibration, and copied the ETC settings. I knew it was risky, due to the warnings posted in the Editor, which is why I'm not butt-hurt about bricking my ECM. However, my naive self figured it was similar to switching to the '06 OS.

Anyways, I flashed the config, and the throttle was totally unresponsive. I basically figured I ruined it, at that point.

Now, trying to revert to the last working config, I get:

"Request download x7f negative response code"

I haven't been able to get past that, reading or writing. However, it will log just fine in the scanner. I even tried bench flashing it, where it had a steady 13.8v, compared to the 11.3v it had in the truck.

So, all in all, don't do what I did. I have another ecm on it's way, but would still like some insight to fixing the throttle issue. I'm not too keen on the idea of a throttle stop, at such a short pedal stroke.


Thanks for reading.

[tris909]

Ecu not emu, damn auto correct

[Earwax]

Are the TAC and APP (pedal) from the same year and model vehicle?

[tris909]

Ecu not emu, damn auto correct

my original post did not come up.
I have seen this happen alot on P59 controllers with modifying pedal rates etc and result dead pedal and no read. Some cases , being 70% , i have been able to recover the ECU doing a write entire with a working or stock file with success most of the time. This works for P01 controllers as well whether they are corrupt or tuner locked.
hope this is of some help to you, i don't think you have anything to loose trying this option.

[Chewy72ss]

Thanks for the responses.

I purchased the TAC and pedal as a set, but seperately from the engine/ecu. It is a fixed metal pedal, with TAC module #12573059. As far as I can tell, this is the correct setup for my '03 Tahoe dropout.

As far as flashing a different file, I've went as far as letting the ECU sit overnight, unplugged, then attempting to bench flash (full write) the original file. I still get the "x7f" error code.

I've already ordered another ecu, and I have a better idea of what not to do.

I'm wondering if there is a way to wire a voltage divider circuit or something in the signal wires from both APP sensors to drop the output down, so pedal travel and tps match. Just a thought.

Thanks again.

[Chewy72ss]

Another thought... I'm not sure if the Tahoe that my motor/ecu came from had adjustable pedals or not. I'm not sure if it would cause an issue that I'm using a fixed pedal now.

[Earwax]

Adjustable pedal option was to move both the brake and throttle pedals either closer or further from the driver.The pedal and tac module have to both be from a truck or a vette.Not 1 from each vehicle. If not matched, it usually causes these problems with mismatch TPS/APP.Try another pedal for a gen 3.

[Earwax]

According to GM parts the TAC module you have is correct for a 03 Tahoe.
The APP may be wrong.
They are different p/ns for a truck or vette.
The pedals are different from 03-05 in a truck.

[Chewy72ss]

The TAC module and gas pedal were purchased together, along with the harness between them. I assume they were from the same vehicle, as they were advertised as such. The gas pedal is definitely a truck pedal. Certainly appears to be '03-'05, judging by the metal construction, and pin count. Not sure on which exact year though.

[Chewy72ss]

UPDATE!

So, I got my replacement ECM (same service #, etc.). This one was from an '03 Avalanche, but in stock form, I still had the pedal travel issue.

I decided to give the '06 OS another shot, but doing it the proper way, this time, and IT WORKED! I did a full write of an '06 Silverado (12587811 OS instead of 12579405) with a 6.0l/4l80e, so I didn't have to do a segment swap again. I copied over the settings from my 5.3 calibration, except for "Throttle Max Rotation % vs. Pedal". In the scanner, the pedal position will still show 150%, but in the physical sense, WOT at the pedal, now equals WOT at the the throttle body.

So glad I tried this, rather than taking the easy way out, and putting a pedal stop in. The truck should have much better street manners, with the not-so-touchy pedal.

Hope this helps anyone with similar issues, in the future.

[Suncc49]

Fighting this issue in my swap..... at about 69% throttle position I am getting 100% TPS... does this cause any issues if I get over that % with the pedal? limp mode ?

[Chewy72ss]

I took care of any and all bugs I could find before I started or drove my truck. However, limp mode or reduced engine power (REP) mode seems to be the typical outcome of mismatched TPS and pedal position readings.

[jglew82]

I know I'm resurrecting this from the dead, but I'm having the same issue. I'm almost certain it's due to the fact my dropout (6.0/4l60e) was from a Yuk with adjustable pedals. The mechanical throw of the pedal is a lot shorter than the fixed pedal. So did you have to do an engine segment swap from the 06 Silverado to fix this? Or was "write entire" the only solution.

[Chewy72ss]

Can't say with any confidence whether or not a segment swap would work, instead of a full write. I basically did the extremes on either side of that option, with the "Write Entire" being successful. Honestly, the DBW issues were the most difficult part of the entire swap. Good luck.

[workingdog]

I hate to speculate, but it seems unlikely that it's because the Yukon came with adjustable pedals. The DBW unit is self-contained. The non-adjustable one is standalone and should sending out it's own 0-100 signal.