Code 31, Engine Speed Governor - 5.7L "G" Series: Notes

The PCM controls the engine speed control governor based upon engine speed (RPM). The PCM sends a pulse width modulation signal to the engine speed control governor module to drive the engine speed control governor motor. Depending upon the amount of governing required, the module translates the PCM data into a voltage signal which it sends to the motor. The motor then pulls back the throttle to the correct overspeed condition.

A Code 31 will set if a fault occurs in the governor module, motor, linkage, wiring or PCM. If Code 31 is set, the PCM will limit engine speed by momentarily reducing fuel delivery to injectors.

1. Determines if engine speed governor module has proper voltage.
2. Applying voltage to the motor will determine motor, wiring and linkage integrity. DO NOT  hold current to motor for longer than 30 seconds or damage to motor will result.
3. This will command full governing to determine if PCM or engine speed governor is at fault.