LMM going back to idle when travelling

[Boots23954]

Hi, I am in Australia, I have a LMM duramax / Allison in a 6WD Toyota, the swap was completed about 3 Years ago, it has been running fine, but today when travelling at highway speed the accelerator stopped responding, the motor would not go above an idle, No engine light, no codes came up.

The fault seems to rest by switching off the ignition and restarting the engine, however it done it about another 6 time before i returned back home.
The ecu has been modified to work in the Toyota, EGR and all pollution gear has been removed, along with all the security coding, it has 5 tunes via a dsp switch, otherwise a standard motor.

Has anyone got an idea of where to start, i don’t think it is in the pedal circuit or i am sure it would bring up a code, I am thinking of an intermittent wiring fault, but not sure where.

Appreciate any help

 

[DAVe3283]

Depending on how the tune was done, it could be a silent code. Often with deletes, the tuner will turn off tons of codes, including some they don't strictly need.

Since it sounds pretty repeatable, I'd grab a factory scan tool or equivalent, and when it happens, read out all 3 accelerator pedal position voltages and the calculated percent. I'm guessing one of them is a bit glitchy and the ECU is failing the pedal, and the tune has the DTC disabled so it doesn't report it.

Sent from my FlashScan V2 using Tapatalk

 

[2004LB7]

as dave said

is the accelerator from the donner vehicle or is it the Toyota one? maybe had to turn off codes to get a Toyota throttle to work and now it's off just enough to kick out

 

[Boots23954]

Hi, Thanks for the replies, I forgot that I have a Dakota Digital Cruise Control that sits in the accelerator pedal circuit, it plugs directly onto the pedal and you then plug the harness into the cruise box, (it sits between the pedal and the ecu) I am beginning to think this unit may be faulty, I will disconnect the unit and see if the fault disappears. The pedal is a genuine GMC Pedal.