LE5 throttle by wire issue

[hefe33]

I have a LE5 in a dune buggy (well 2 of them actually)
donor car is a 2006 G6 with a ECU from a 2007 HHR (E67 ECU)

we have removed vats, and a few DTC's that were not needed, and it runs pretty good overall,
HOWEVER...
once in a while like when grabbing 2nd gear and accelerating the gas pedal just quits working
just as if you unplugged it.. not "limp mode" it just plain doesn't work... dead..
if I reset the computer it comes back and works fine..
no DTC's show.. just no pedal at all.. idle only


as a test, we started the engine and unhooked the pedal, and then hooked it back up, it rendered the pedal useless until we cleared the codes (it threw p2122 and p2127)
the difference being when we unhooked it intentionally it DID throw a code, when it does it on it's own it does not throw a code.

both buggies have the same "tune" and both suffer the same problem

one important thing to note is we used a 6 wire coated trailer wire to run the APP wires to the front of the buggy (the ECU is in the rear of the buggy)
approximately 8 feet or so of this very high quality trailer wire is used on both buggies.

is it possible the resistance is all wrong running through this trailer wire and the ECU is shutting off the pedal?

thanks in advance

Hefe

[cobaltssoverbooster]

as long as the cable has not shorts to ground or high resistance the ecu wont care.
tell us more though:
you have a bcm installed?
are you bypass wiring anything if you are?
any ecu learns performed through the vcm scanner?
is this a from day 1 ignition problem or just start acting up on both problem?

the most amount of info you can supply the more things we can rule out to speed you along.

i know a guy iirc his name was aaron and he put a le5 in a hill climb buggy with axle to chain driven hub system. he loves it to death!
he had a similar issue with throttle pedal having weird symptoms. i remember it decent and im pretty sure it ended up being a table that was used to reference a specific pattern off of the throttle pedal. ill look into my log of old problems and fixes i keep for ecotec motors.

[hefe33]

Thanks for the prompt reply!
No, no BCM
Not sure what you mean by ecu learns...
And yes, this problem has been from day 1

Can't wait to hear how your guy solved that problem

Thanks again

[cobaltssoverbooster]

Electronic Throttle Control > Desired Throttle Area > Axis type got switched in this guys case. without wheel speed sensors the VSS axis was useless.
if that causes problems for you then immediately revert back to a previous tune as all issues are not the same and electronic pedal issues can have severe consequences. (this is why 99% of stand alone computers don't have electronic throttle controls)

[hefe33]

mine is set to RPM not VSS (I just checked), so is this NOT my problem?

any other suggestions?

[hefe33]

of course, I could post my .hpt file here if it helps anyone

[cobaltssoverbooster]

did you try setting it to vss?

[hefe33]

no, .. I will give that a shot and report back.. thanks for the help

[hefe33]

changed to VSS and it failed before the end of the driveway... same thing... gave it a little gas, dropped the clutch... and nothing on the pedal... just idle..

any other suggestions?

[cobaltssoverbooster]

Grab a log of it failing out. Lets see exactly what it doin. Log as many parameters as possibly. Pedal position, throttle position, intake temps, rpm, cam sensor, ignition. ....just fill it up that way we can pinpoint systems

[hefe33]

I'll see what I can do this weekend.. thanks