For 1990-2009 cars

### 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 customers concern.

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

• | Check the vehicle system voltage:

- | There is not a charging system concern. All charging system concerns must be repaired before programming a control module.

- | 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 vehicles 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 vehicles battery, including the following components:

• | Twilight sentinel

• | Interior lights

• | Daytime running lights (DRL)--Applying the parking brake, on most vehicles, disables the DRL system. Refer to the Owner's Manual.

• | HVAC systems

• | Engine cooling fans

• | Auxiliary coolant pumps

• | Radio, cassette or CD player

• | The ignition switch is in the proper position. The Techline terminal 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.

• | All tool connections are secure, including the following items:

- | The RS-232

- | The connection at the DLC

- | The voltage supply circuits

### Programming the ECM

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

Important: The ECM can only be programmed using the Pass-Thru Programming method. The Pass-Thru Programming method requires the use of a scan tool in series with the Techline Terminal and the DLC.

1. Turn OFF the ignition.
2. From the Techline terminal, select Service Programming System.
3. Select Pass-Thru as the Diagnostic Tool.
4. Select the Programming Process you are using.
5. Select Vehicle for the ECU location.
6. Complete the vehicle information on the Connect Scan Tool/Determine Vehicle screen.
7. Turn ON the ignition, with the engine OFF.
8. Install the Tech 2 to the data link connector (DLC).
9. Connect the RS-232 cable to the Tech 2 and the Techline terminal.
10. Turn ON the Tech 2 and wait for the Start screen.
11. Verify the displayed VIN on the Techline terminal with the vehicle VIN. Correct the VIN as necessary.
12. Select the type of module you are programming.
13. Select the type of programming that you are performing.
14. Select the appropriate calibration file.

Important: DO NOT turn OFF the ignition if the programming procedure is interrupted or unsuccessful. Ensure that all the ECM 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 Engine Control Module Replacement .

15. Verify the Current calibration with the Selected calibration then select Next. This will initiate the download of the calibration files.
16. After the download is complete, EXIT Service Programming.
17. Turn OFF the ignition for 30 seconds.
18. If the control module was replaced, the following procedures must be performed:

• | Idle Learn

• | Theft deterrent password learn procedure--Refer to Engine Control Module Replacement

• | Perform the Inspection/Maintenance (I/M) Complete System Set Procedure if the vehicle is from an area participating in OBD system inspections as part of a state I/M program.

### Programming Verification

1. Use the scan tool in order to 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 ECM.

• | 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.

4. Program the control module. If the control module still cannot be programmed properly, replace the control module. Refer to Engine Control Module Replacement .