Cummins ISL CM850 (2003-06) Fault Code: 523 PID: 89 SPN: 611 FMI: 2 Auxiliary Intermediate (PTO) Speed Switch Validation – Data Erratic, Intermittent, or Incorrect. The position of the intermediate speed control switch 1 does not match the position of the intermediate speed control validation switch.

Cummins ISL CM850 (2003-06) Fault Code: 523 PID: 89 SPN: 611 FMI: 2 Auxiliary Intermediate (PTO) Speed Switch Validation – Data Erratic, Intermittent, or Incorrect. The position of the intermediate speed control switch 1 does not match the position of the intermediate speed control validation switch.

When activated by switch or hand throttle, the Intermediate Speed Control feature governs engine speed to the corresponding preset speed. The three preset speeds can be adjusted with an increment or decrement switch but can not exceed the low or high idle governor engine speed limits.

If Intermediate Speed Control validation is being use, Intermediate Speed Control Switched Set Speed Three will be used as the validation input.

Possible repairs:

1)Replace the intermediate speed control switch.
2)Repair or replace the OEM harness.