Ecotec 2.4 p0606 - "dead' gas pedal

[basilweenie]

Was testing my race car which has a swapped 2.4. ECU is E67 which was tuned by a 3rd party. We found that after driving for an hour or two, the throttle action got flaky. At a point, the throttle went dead. No response to pedal input. If you reset the ecu, pedal would work for a bit, then go dead. We eventually got to a point where we could reproduce the problem. We were looking at codes when the thottle was dead. We found that if you slowly depressed the gas pedal, at about 35% the code would show up and the pedal would go dead. Resetting codes would allow it to work, until depressed again. Interestingly enough if you moved the gas pedal say quickly from 0 -100% the code would not manifest itself. Changing out the throttle body and gas pedal made no difference. Changing to a spare stock ECU made the problem go away.

Looking at the tune, the guy had changed the ETC throttle table axis from Vss to RPM (in spite of all the warnings). I changed the table back to stock and reflashed all. Behavior of throttle now appears normal. No p0606. Has anyone seen this sort of behavior? Since I do not have a Vss signal, what is the implication of using Vss for the throttle table axis rather than rpm?

[b3tuning]

Without a VSS signal, there would be no point having VSS as an axis on the ECT table. It would be the same as having a 2d table.

Also, another cause I've found for getting a dead DBW and going into an undriveable limp mode is that the plastic stops around the pivot for the gas pedal break allowing slightly more pedal travel. This happened in our off road TT during a night race and was incredibly dangerous having to kill all power to reset the ECU (dead in the trail with no lights !!!) every time the throttle was slowly modulated. I'll upload pictures of the pedal when I get to the shop in the morning.

Wish there were access to tables to adjust the voltage range of the ETC/TAC and also to the failure mode tables... we got nerfed hard twice while dead on the course resetting, until we made it to a remote pit to swap out pedals.

[basilweenie]

Thanks for the tip about the pedal stops. That may be part of one of our problems. We had a situation similar to what you describe. Car when into limp for no reason. Cycled ignition off and on and limp went away.