Cummins ISB CM550 (1990-94) Fault Code: 432 PID: 91 SPN: 91 FMI: 13 Accelerator Pedal Circuit (ISS)

Circuit Description
The accelerator pedal assembly relays the accelerator percentage requested by the operator
to the electronic control module (ECM). Percent accelerator is used to determine fueling. The
accelerator position sensor and the idle validation switch on the accelerator pedal are adjusted
at the factory to provide the correct output signals.

NOTE: The connector pin letters shown for the accelerator pedal wiring in these
troubleshooting steps are examples of representative sensors. The connector pin assignments
can vary with the equipment manufacturer, but the base troubleshooting logic will still apply.

Component Location
The accelerator position sensor and the idle validation switch are located on the accelerator
pedal in the cab.

Shop Talk
Confirm that the idle validation switch (IVS) is properly calibrated. Refer to the accelerator
pedal manufacturer’s instructions for adjustment information.

NOTE: The three wires in the accelerator position sensor circuit must be twisted together.
Depending on ground location, IVS will, perhaps, only have two wires.