GM Service Manual Online
For 1990-2009 cars only

Powertrain Control Module Programming Onboard

Before Programming a Control Module

Important: Do NOT program a control module unless you are directed by a service procedure or you are directed by a General Motors Corporation service bulletin. Programming a control module at any other time will not permanently correct a customer's concern.

Ensure the following conditions are met before programming a control module:

    • Vehicle system voltage
       - There is not a charging system concern. All charging system concerns must be repaired before programming a control module.
       - The battery voltage is greater than 12 volts but less than 16 volts. The battery must be charged before programming the control module if the battery voltage is low.
       - A battery charger is NOT connected to the vehicle's battery. Incorrect system voltage or voltage fluctuations from a battery charger, may cause programming failure or control module damage.
       - Turn OFF or disable any system that may put a load on the vehicle's battery:
   • The twilight Sentinel
   • The interior Lights
   • The daytime running lights (DRL)--Applying the parking brake, on most vehicles, disables the DRL system. Refer to the Owners manual.
   • The HVAC systems
   • The engine cooling fans
    • The ignition switch is in the proper position. The scan tool prompts you to turn ON the ignition, with the engine OFF. Do NOT change the position of the ignition switch during the programming procedure unless instructed to do so.
    • Secure all tool connections:
       - The RS-232
       - The connection at the DLC is secure.
       - The voltage supply circuits
    • DO NOT disturb the tool harnesses while programming. If an interruption occurs during the programming procedure, programming failure or control module damage may occur.

PCM Programming Set Up with Special Tool

Notice: The PCM will be damaged if proper programming procedures are not followed.

  1. Ensure that the following conditions have been met:
  2. • The battery is fully charged.
    • The scan tool cable connection at the data link connector (DLC) is secure.
  3. Turn OFF the ignition.
  4. Remove the passenger side floor access panel. Refer to Front Floor Kick-Up Panel Replacement in Interior Trim.

  5. Object Number: 369961  Size: LH
  6. Remove the splice pack/star connector shorting bars from both splice pack/star connectors (2, 3). It may be necessary to remove splice pack/star connectors from the mounting positions.
  7. Install the star connector cable #1 from the J 42236 Serial Data Link Tester to the 12 pin splice pack/star (3). This is the connector with 8 or 10 wires.
  8. Install the star connector cable #2 from the J 42236 to the 12 pin splice pack/star (2). This is the connector with 4 wires.
  9. Select the star connector cable #1 on the J 42236 toggle switch.
  10. Select position B on the J 42236 .

Remote Programming

  1. Turn ON the ignition, with the engine OFF.
  2. Turn OFF all vehicle accessories.
  3. With the Tech 2, select Service Programming.
  4. Identify vehicle information as requested by the Tech 2.
  5. Verify the displayed VIN with the vehicles VIN. If the displayed VIN does not match the actual VIN, write down the actual VIN and correct the VIN at the Techline terminal.
  6. When complete, exit Service Programming.
  7. Turn OFF the Tech 2 and disconnect the Tech 2 from the vehicle.
  8. Turn OFF the ignition.
  9. Connect the Tech 2 to the Techline terminal.
  10. Select Service Programming.
  11. Select Tech 2 as the tool you are using.
  12. Select the type of programming to be performed.
  13. Verify the displayed VIN with the vehicles VIN. Correct the VIN as necessary.
  14. Select the type of module you are programming.
  15. Identify the type of programming that you are performing.
  16. • Normal--This type of programming is for updating an existing calibration or programming a new controller.
    • Vehicle Configuration Index (VCI)--This selection is used if the vehicle VIN is unavailable or not recognized by the Techline terminal. Observe, you will need to contact the Techline Customer Support center to use this option.
    • Reconfigure--This is to reconfigure a vehicle, such as tire size and axle ratio changes.
  17. Select the appropriate calibration file.
  18. Ensure all connections are secure.
  19. Select Reprog in order to initiate the download of the new calibration to the Tech 2.
  20. After the download is complete, turn OFF the Tech 2.
  21. Disconnect the Tech 2 from the Techline terminal.
  22. Install the Tech 2 to the data link connector (DLC).
  23. Turn ON the Tech 2.
  24. Turn ON the ignition, with the engine OFF.
  25. Select Service Programming.
  26. Important: DO NOT turn OFF the ignition if the programming procedure is interrupted or unsuccessful. Ensure that all the PCM and DLC 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. Refer to Powertrain Control Module Replacement .

  27. Select Program.
  28. After the download is complete, EXIT Service Programming.
  29. Turn OFF the ignition for 30 seconds.
  30. Turn OFF the Tech 2.
  31. If a control module is replaced the following service procedures must be performed:
  32. •  Crankshaft Position System Variation Learn
    •  GM Oil Life System Resetting
    •  Idle Learn
    •  Inspection/Maintenance (I/M) Complete System Set Procedure
    •  Programming Theft Deterrent System Components

Programming Verification

  1. With a scan tool, clear the DTCs.
  2. Attempt to start the engine.
  3. Repeat the service programming procedure if the engine does not start or operates poorly. Perform the following procedures before programming the PCM:
  4. • Ensure the control module and DLC connections are OK.
    • Ensure the Techline operating software is up to date.
    • Ensure the calibration part number is correct for the vehicle.
  5. Attempt to program the control module. If the control module still cannot be programmed properly, replace the control module. Refer to Powertrain Control Module Replacement .

Powertrain Control Module Programming Offboard

Before Programming a Control Module

Important: 

   • Do NOT program a control module unless you are directed by a service procedure or you are directed by a General Motors Corporation service bulletin. Programming a control module at any other time will not permanently correct a customer's concern.
   • 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.
   • DO NOT disturb the tool harnesses while programming. If an interruption occurs during the programming procedure, programming failure or control module damage may occur.

Ensure that all connections are secure at the following locations:

    • The Off-Board Programming Adapter
    • The Tech 2
    • The control module
    • The Techline terminal

Off-Board Programming

  1. Obtain the VIN of the vehicle for which the control module is being programmed.
  2. With the Techline terminal, select Service Programming.
  3. Select Tech 2, Reprogram ECU, and Off-Board Programming Adapter as the ECU location.
  4. 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.
  5. With the Tech 2, select Service Programming Request Information function. The Tech 2 communicates with the control module and receives the access code.
  6. With the Tech 2, exit the Service Programming Request Information.
  7. Disconnect the Tech 2 from the Off-Board Programming Adapter.
  8. Connect the Tech 2 to the Techline terminal.
  9. Turn ON the Tech 2.
  10. With the Techline terminal, enter the VIN of the vehicle that will be receiving the control module.
  11. The Techline terminal will display the message, attaching to database.
  12. Identify what type of programming that you are performing.
  13. Select the appropriate calibration file.
  14. Ensure all connections are secure.
  15. 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.
  16. After the download is complete, turn OFF the Tech 2.
  17. Disconnect the Tech 2 from the Techline terminal.
  18. Connect the Tech 2 to the Off-Board Programming Adapter.
  19. With the Tech 2, select Service Programming.
  20. Important: 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.

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