GM Service Manual Online
For 1990-2009 cars only

Important: Consult the PTO driven accessory manufacturer for the engine speed requirements for the proper operation of the PTO accessory.

Important: The PTO/Fast Idle System must be reprogrammed using a scan tool whenever the PCM is replaced or reprogrammed.

The Power Take Off (PTO) engine speeds must be programmed into the PCM according to the installed aftermarket accessories /equipment manufacturers body builders recommendations requirements recommended PTO output speeds

When the Power Take OFF (PTO) unit is engaged, PTO output speed is proportional to the engine speed.

In order to program the PTO or Fast Idle System, perform the following:

  1. Turn On the ignition leaving the engine OFF.
  2. Using a scan tool, select the option for PTO programming.
  3. Select the proper engine speed options for the PTO and the fast idle.
  4. Start the engine and allow the engine speed to stablize.
  5. If you are checking the PTO engine speed, depress and release the PTO ENABLE switch.
  6. Turn ON the Cruise Control at the Multifunction lever.
  7. Attempt to control the engine speed by using the SET/COAST and RESUME/ACCEL switches or the body builder installed remote PTO controls (if equipped). If the engine speeds can not be controlled by the Cruise Control switches refer to (PTO Funtional Check).
  8. If you are checking the Fast Idle engine speed, depress and release the Fast Idle switch. The engine speed should increase to the value selected on the scan tool. If the engine speed did not increase to the value selected on the scan tool refer to (Fast Idle System Diag).