Circuit Description
The auxiliary speed input is a frequency signal from an auxiliary speed or pressure pickup. It is
sent to the electronic control module (ECM) and is used to control the engine speed. Auxiliary
reference speed is based on the throttle position.
Component Location
The auxiliary speed or pressure pickup device location is dependent on the original equipment
manufacturer’s (OEM) application. Refer to OEM manual for component location.
Shop Talk
The auxiliary speed governor controls engine speed based on a measured auxiliary speed or
pressure. The auxiliary speed governor feature must be enabled in the calibration and set
properly for speed or pressure, depending on the OEM application.
Cummins ISB CM550 (1990-94) Fault Code: 488 PID: 105 SPN: 105 FMI: 0 Intake Manifold Air Temperature Sensor – Engine Protection Circuit
Cummins ISB CM550 (1990-94) Fault Code: 444 PID: SID 232 SPN: 620 FMI: 1 Remote Accelerator Supply Circuit
Cummins ISB CM550 (1990-94) Fault Code: 444 PID: SID 232 SPN: 620 FMI: 3 Remote Accelerator Supply Circuit
Cummins ISB CM550 (1990-94) Fault Code: 443 PID: SID 232 SPN: 620 FMI: 1 Accelerator Position Sensor Circuit
Cummins ISB CM550 (1990-94) Fault Code: 443 PID: 91 SPN: 620 FMI: 1 Accelerator Position Sensor Circuit
Cummins ISB CM550 (1990-94) Fault Code: 443 PID: SID 232 SPN: 620 FMI: 3 Accelerator Position Sensor Circuit
