Article 2019-07-28 17:42:58

_GM (UF3) - Fast Idle

Required Conditions

These conditions must be met for Fast Idle to work:

Park Brake must be set
Transmission/PRNDL must be in Park (P) or Neutral (N).
The Brake must not be pressed.
Vehicle Speed must be zero.

Fast Idle is controlled using the Cruise Control buttons located on the left-hand side of the steering wheel.

Enable Fast Idle

After the required conditions above have been met, you can Enable Fast Idle by pressing and releasing the Cruise Control “ON” switch, the LED indicator on the switch will illuminate and Fast Idle will engage to achieve the single preset fast idle speed of 1000 or 1200 rpm depending on vehicle model, year and engine application.

Disable Fast Idle

Any of these conditions will cancel Fast Idle:

- - Turn Cruise Off. Press and Release the Cruise Control “ON/OFF” switch.
  - Press and Release the Cruise Control “SET” switch while in high idle.
  - Press the brake pedal.
  - Press and Release the Cruise Control “CANCEL” switch.
  - Release the Park Brake.
  - Move the Transmission Shift Lever (PRNDL) from Park (P) or Neutral (N).
  - Apply the accelerator pedal greater than 25%

Installation

Engine idle up feature can be added by the dealer (at extra cost) on units provided it was available on your model but not ordered.

Available on these Models built after 2008:

- 2500HD/3500HD Pickup or Chassis Cab
- 2500/3500/4500 Passenger, Cargo, Cutaway Van.

Available with these Engines:

- Gasoline (LY6 or L96) with Cruise Control (K34).
- Diesel ( LGH, LML, LMM, LWN or L5P) with Cruise Control (K34).

Note: Fast Idle is not available on 1500 Models.

Adding the Fast Idle (UF3) feature is accomplished by reprogramming the Vehicle’s Body Control Module (BCM). GM Dealers can acquire a new Vehicle Configuration Index (VCI) by contacting Techline Customer Support Center (TCSC). A support center consultant will create the new VCI with UF3 option as part of the vehicle option content.

Note: TCSC typically imposes an administrative fee on the dealers requesting the updated VCI and this fee may be passed onto the customer. This fee is in addition to the labor charges for the reprogramming of the vehicle. The newly created VCI is readily available for use in the reprogramming of the vehicle’s BCM. Dealers simply need to perform a programming event on the BCM to now add the feature/option.

Bulletin available here: https://www.gmupfitter.com/files/media/photo/795/UI%20Bulletin_82b.pdf