Off-Board Programming (Avalanche, Astro, Aztek, Blazer, Bravada, Cab & Chassis - 8.1L, Chevy Express - 5.0L, 5.7L & 8.1L, Cutaway - 5.7L & 8.1L, Envoy, Envoy XL, Escalade, Escalade EXT, Jimmy Canadian, Montana, Rendezvous, RV Cutaway - 5.7L & 8.1L, S10 Pickup - 4.3L, Safari, Savana - 5.0L, 5.7L & 8.1L, Savana Camper Special - 5.7L & 8.1L, Savana Special - 5.7L & 8.1L, Sierra - 4.3L, 4.8L, 5.3L, 6.0L & 8.1L, Silhouette, Silverado - 4.3L, 4.8L, 5.3L, 6.0L & 8.1L, Sonoma - 4.3L, Suburban, Tahoe, Trailblazer, Venture, Yukon & Yukon XL)

NOTE: DO NOT program a control module unless you are directed by a service procedure or you are directed by a technical service bulletin. Programming a control module at any other time will not permanently correct a customer's concern.

NOTE: DO NOT disturb the tool harnesses while programming. If an interruption occurs during the programming procedure, programming failure or control module damage may occur.

Before Off-Board Programming a Control Module

Ensure that all connections are secure at the following locations:
1. The Off-Board Programming Adapter.
2. The Tech 2™.
3. The control module.
4. The Techline™ terminal.

The Off-Board Programming is used in situations where a control module must be programmed without having the vehicle present. The Off-Board Programming Adapter must be used to perform the Off-Board Programming procedure. The adapter allows the control module to power up and allows the Tech 2™ to communicate with the control module.

Off-Board Programming Procedure

Obtain the VIN of the vehicle for which the control module is being programmed.
With the Techline™ terminal, select Service Programming.
Select Tech 2™, Reprogram ECU, and Off-Board Programming Adapter as the ECU location.
Connect the control module, Off-Board Programming Adapter, and the Tech 2™ as described on the Techline™ terminal. Ensure you use the correct harness connector from the Off-Board Programming Adapter kit.
With the Tech 2™, select Service Programming Request Information function. The Tech 2™ communicates with the control module and receives the access code.
With the Tech 2™, exit the Service Programming Request Information.
Disconnect the Tech 2™ from the Off-Board Programming Adapter.
Connect the Tech 2™ to the Techline™ terminal.
Turn ON the Tech 2™.
With the Techline™ terminal, enter the VIN of the vehicle that will be receiving the control module.
The Techline™ terminal will display the message, attaching to database.
Identify what type of programming that you are performing.
Select the appropriate calibration file.
Ensure all connections are secure.
The Techline™ terminal displays a summary screen that summarizes your selections. After confirming you choices, the Techline™ terminal automatically loads the calibration files to the Tech 2™.
After the download is complete, turn OFF the Tech 2™.
Disconnect the Tech 2™ from the Techline™ terminal.
Connect the Tech 2™ to the Off-Board Programming Adapter.
With the Tech 2™, select Service Programming.

NOTE: DO NOT turn OFF the Off-Board Programming Adapter if the programming procedure is interrupted or unsuccessful. Ensure the control module and the Off-Board Programming Adapter connections are secure and the Techline™ operating software is up to date. Attempt to reprogram the control module. If the control module cannot be programmed, replace the control module. See appropriate REMOVAL, OVERHAUL & INSTALLATION article.

With the Tech 2™, select Program.
After the download is complete, exit Service Programming.
Turn OFF the Off-Board Programming Adapter.