Important: The following steps must be completed before using the symptom tables.
- Review the system Description and Operation in order to familiarize yourself with the system functions. Refer to 
Power Take-Off (PTO) Description and Operation
 .
 
- Perform the 
Diagnostic System Check - Vehicle
 before using the Symptom Tables in order to verify that all of the following are true:
 
| •  | There are no diagnostic trouble codes (DTCs) set. | 
 
| •  | The control module or modules can communicate via the serial data link. | 
 
Visual/Physical Inspection
|     •  | Inspect the easily accessible and visible system components for obvious damage or conditions which could cause the symptom. | 
 
|     •  | Inspect the transmission for the proper transmission fluid level. | 
 
|     •  | Inspect the hydraulic reservoir for the proper hydraulic fluid level. | 
 
|     •  | Inspect the upfitter connections at the transmission. | 
 
Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:
|     •  | Power Take-Off Does Not Engage | 
 
|     •  | Engine RPM Does Not Increase With Power Take-Off Engaged | 
 
|     •  | Power Take-Off Indicator Inoperative |