Cummins ISB CM550 (1990-94) Fault Code: 768 PID: SID 009 SPN: 923 FMI: 11 Output Device Driver (Trransmission Shift Modulation)

Circuit Description
The output device driver is a device used by the electronic control module (ECM) to control the
transmission shift modulation signal.

Component Location
Refer to an OEM diagram for the location of the transmission shift modulator.

Shop Talk
Output device driver could be malfunctioning due to a failed engine harness, a bad ground on the
transmission shift modulator connector, or a bad transmission shift modulator.