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 troubleshooting and repair 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: 298 PID: 223 SPN: 1084 FMI: 4 OEM Pressure Sensor Circuit
Cummins ISB CM550 (1990-94) Fault Code: 297 PID: 223 SPN: 1084 FMI: 3 OEM Pressure Sensor Circuit
Cummins ISB CM550 (1990-94) Fault Code: 286 PID: SID 231 SPN: 639 FMI: 13 J1939 Datalink Multiplexing
Cummins ISB CM550 (1990-94) Fault Code: 285 PID: SID 231 SPN: 639 FMI: 9 J1939 Datalink Multiplexing
Cummins ISB CM550 (1990-94) Fault Code: 284 PID: 190 SPN: 190 FMI: 4 Engine Speed Sensor Supply
Cummins ISB CM550 (1990-94) Fault Code: 284 PID: 190 SPN: 190 FMI: 3 Engine Speed Sensor Supply
