2007 E450 6.0 L Ambulance Wrench Light

[FAS2627]

Hello,
Recently new ambulance exibited a strange condition.
Either on warm restart, or after coming to a stop and idling, drivers puts rig back in Drive, from Park, depresses gas pedal and vehicle does not move.
Engine RPM remains at idle, and Wrench light come on.
Transmission does engage.

Turn ignition off and restart, and vehicle operates OK. Sometimes with sometimes without the Wrench light.

Any thoughts ?

Thanks

[08Powerstroked]

Its the drive by wire, meaning there is something wrong with the pedal

[vitalidle]

Yeah its possible its the tps or throttle position sensor. Need to have it scanned