Circuit DescriptionThe output device driver is a device used by the electronic control module (ECM) to control thetransmission shift modulation signal. Component LocationRefer to an OEM diagram for the location of the transmission shift modulator. Shop TalkOutput device driver could be malfunctioning due to a failed engine harness, a bad ground on thetransmission shift modulator connector, or a bad transmission shift modulator. Cummins ISB CM550 (1990-94) Fault Code: 599 PID: SID 025 SPN: 640 FMI: 14 Auxiliary Commanded Dual Output Shutdown – Special Instructions Cummins ISB CM550 (1990-94) Fault Code: 529 PID: SID 051 SPN: 703 FMI: 3 Dual-Output Driver...

Circuit DescriptionThe OEM device input to engine protection allows vehicle OEMs to wire up a device, such as ahydraulic oil temperature limit switch, transmission temperature limit switch, etc., to the ECM.Some units have been upfitted with a Fuel Pressure Switch. The ECM will monitor values fromthis device the same as other engine protection inputs, such as coolant level, etc.. If athreshold value is exceeded, engine speed derate will occur and possible engine shutdown. Component LocationThe location of the OEM device is dependent upon the OEM. If the unit has a fuel pressureswitch installed, it is located at the fuel filter...