ISBe/ISB Series Engines – Engine Will Not Reach Rated Speed (RPM)

Electronic fault codes are active

For instructions on how to read active fault codes, refer to Diagnostic Fault Codes in Section 1. If fault codes are active, contact a Cummins Authorized Repair Facility.

Throttle plate position sensor or circuit is malfunctioning (if equipped with a throttle plate position sensor)

Check the throttle position sensor and circuit. Refer to a Cummins Authorized Repair Facility.

Vehicle parasitics are excessive

Check the vehicle brakes for dragging, transmission malfunction, cooling fan operation cycle time, and engine-driven units. Refer to the OEM service manual.

Engine power output is low

Refer to the Engine Power Output Lowsymptom tree.