GM Service Manual Online
For 1990-2009 cars only

Important: The following steps must be completed before using the symptom tables.

  1. Perform the Power Take-Off (PTO) Diagnostic System Check before using the Symptom Tables in order to verify that all of the following are true:
  2. Refer to Diagnostic System Check - Power Take-Off (PTO) .

    • There are no DTCs set.
    • The control module(s) can communicate via the serial data link.
  3. Review the system Description and Operation in order to familiarize yourself with the system functions. Refer to Power Take-Off (PTO) Description and Operation .

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