DTC 31: Engine Speed Governor - "G" Series: Notes

Control module controls engine speed control governor based upon engine speed (RPM). Control module sends a pulse width modulation signal to engine speed control governor module to drive engine speed control governor motor. Depending upon amount of governing required, module translates control module data into a voltage signal which it sends to motor. Motor then pulls back throttle to correct overspeed condition. A Code 31 will set if a fault occurs in governor module, motor, linkage, wiring or control module. If Code 31 is set, control module 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 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 control module or engine speed governor is at fault.