U0608 means the powertrain control module has lost communication with the 'C' circuit inside the accelerator pedal position sensor assembly. This is almost always caused by a fault in the sensor itself or its wiring, not by a failed engine computer.
The internal sensor 'C' circuit has electrically failed, which is the most common reason for a permanent loss-of-communication fault on this specific circuit.
Opens, shorts-to-ground, shorts-to-voltage, or high resistance in the harness disrupt the signal or reference lines needed for communication.
Moisture intrusion or fretting at the pedal sensor or control module connector can cause intermittent or total loss of contact.
If the module-supplied reference voltage or ground to the pedal assembly is missing, the sensor cannot communicate.
A rare internal PCM fault can set this code; module replacement should only be considered after the sensor and entire circuit are proven fault-free.
No. The engine computer is rarely the cause. The vast majority of U0608 faults are due to a failed accelerator pedal position sensor or a wiring issue between the sensor and the module.
The vehicle often defaults to reduced power mode, which limits acceleration and can be unsafe in traffic. Diagnosis and repair are recommended before continued driving.
It designates the third internal sensing element or redundant circuit within the accelerator pedal position assembly, not a separate external component.
Severely low system voltage can cause intermittent communication errors, but a persistent U0608 almost always points to a specific circuit or sensor fault rather than the battery.