Backup Park Lock Actuator Arming (with MHG): Introduction

The Backup Park Lock function is electrically isolated from the Transmission Range Control Module, and forces the transmission manual shaft to the Park position under specified conditions. Under these conditions the vehicle is put in Latent Fault Mode, refer to Latent Fault Mode Description . The procedures below are designed to assist in the arming of the Backup Park Lock Actuator when the position of the actuator becomes unknown. Before you start, read these procedures carefully and completely. For further information regarding the Transmission Range Selector system refer to Electronic Transmission Range Selector Description .

Before Running the Arming Procedure

• Ensure Transmission Range Control Module and Chassis Control Module software packages are the most current software available.
• Resolve any current DTC's that are present relating to the Electronic Transmission Range Selector system prior to running learn procedure. Refer to Electronic Transmission Range Selector Description . Faults in any component or module that work together in this system may cause a learn procedure failure.
• Ensure the MDI tool is equipped with the latest software and is securely connected to the data link connector. If there is an interruption during learn, learn failure or ECU damage may occur.
• Stable battery voltage is critical during programming. Any fluctuation, spiking, over voltage or loss of voltage will interrupt programming. When required, install a battery maintainer or power supply that provides a steady and stable voltage. Do not use a battery charger, as charging voltage will often fluctuate when connected to the vehicle. This may interrupt programing. If a battery maintainer is not available, connect a fully charged 12 V jumper or booster pack disconnected from the AC voltage supply.
• Turn OFF or disable systems that may put a load on the vehicles battery such as; interior lights, exterior lights (including daytime running lights), HVAC, radio, etc.

Starting the Arming Procedure

1. With your foot off the brake, press and hold the Start/Run Button for 10 seconds to set the ignition correctly.
2. Install a scan tool.
3. Verify that the transmission fluid temperature is 50°F (10°C) or greater before running the arming procedure.
4. In the scan tool under Transmission Range Control Module, Configuration / Reset Functions perform the Backup Park Lock Actuator Arming procedure. Follow all on-screen instructions.
5. If arming procedure failure occurs, refer to wiring diagnostics to resolve any electrical faults.
6. Attempt rerunning the arming procedure 2 additional times before replacing Transmission Range Control Module. If the test successfully completed, cycle the ignition OFF.
7. After the Backup Park Lock Actuator Arming procedure has completed successfully, perform the Diagnostic Repair Verification .
8. Clear DTCs after arming is complete. Clearing powertrain DTCs will set the Inspection/Maintenance (I/M) system status indicators to NO.