Programming ECM For PTO Idle Up Operation On 6.6L Engine - keywords diesel engage fast high information input operation PCM reprogram RPM speed

This PI was superseded to update Recommendation/Instruction with (Or "Vehicle Control Systems" on later models) in step 2. Please discard PIT4507.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Programming ECM For PTO Idle Up Operation On 6.6L Engine.

Connect the Tech 2 and follow the steps below to program the ECM for idle up feature with PTO operation:

1. Turn on tech 2 and build the vehicle
2. select "Powertrain" (Or "Vehicle Control Systems" on later models)
3. select "Special Functions" (or "Module Setup" on later models)
4. select "PTO Options"
5. select "Change Options" (soft key at bottom of the screen)
6. select F1 "PTO Preset Speed Control"
7. select pto max engine speed set to 2200 -4400- rpm (not below 2200)

The steps below will not allow the engine rpm to exceed the rpm setting even during normal driving

8. select stand by speed (base fast idle ) set to 1200 (this setting is initial fast idle)
9. select PTO set speed -set to 1400 rpm
10. select PTO resume speed - set 1700 rpm
11. select PTO max engage speed - set to 1800 rpm (PTO engagement inhibit speed)
12. select PTO engine shutdown - no
13. select PTO engage relay - no
14. select PTO feed back - no
15. select "Reprogram" (soft key at bottom of screen) "Waiting For Data" displays on screen-once data comes back verify settings remain
16. key off- until tech 2 "beeps" and screen shows "no communication" (Very important step if missed setting will not store)
17. key on - verify settings remain on list
18. operate pto

Note: The above selections for PTO idle up on a 6.6L engine is the most common configuration. Other selections are available.

Inquiries regarding the PTO operation can also be referred to GM Upfitter Integration at their Engineering Support Hotline 1-800-875-4742. Or online at www.gmupfitter.com

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.