[b3lha]

Originally Posted by Trevor

As a result of the issues involved, and the fact that I have been deeply involved with control systems, the new “fly by wire” set ups worry me. Have they got it right? Is anyone here aware of the details?

The recent model Subaru drive-by-wire cars have TWO potentiometers on the accel pedal, operating in opposite directions. The ECU program contains logic to check that the signals are consistent with each other and will throw an error code if either potentiometer gives trouble.

The throttle valve itself also has two potentiometers and the same principle applies. The only real possibility of trouble comes if the pedal becomes mechanically stuck - the problem Toyota are having.

The DBW system has big advantages on turbo-charged cars. The ECU can regulate the boost pressure using both the throttle and the wastegate. As I understand it, at 50% accelerator, it is more efficient for the ECU to open the throttle 100% and regulate the airflow using the wastegate solenoid than it is to have the turbo blowing hard into a half-open throttle.

All things considered, DBW is much better than the old cable system.