Enabling or Disabling Passive Unlocking

The passive door unlocking feature, which uses the button on a door handle (Fig. 23) to unlock many 2019-2020 GM models, can be enabled and disabled using the Remote Keyless Entry transmitter (key fob). In addition, on some 2020 models, the passive door unlocking function can be changed in the Settings menu on the infotainment screen.

 

Fig. 23

 

Passive door unlocking is now widely available throughout the GM lineup. Refer to Bulletin #18-NA-279 for a complete list of models.

The passive door unlocking feature uses the door handle switch signal circuits to provide inputs to the keyless entry control module when a door handle button is pressed. The keyless entry control module provides a 12 V signal to each exterior door handle switch via the door handle switch signal circuits. When a door handle button is pressed, the switch closes and the voltage signal within the signal circuit is pulled to ground. The keyless entry control module will detect the voltage drop and a low frequency antenna will transmit a challenge to the key fob, which must be within three feet of the door. If the challenge is met, the key fob will respond and the keyless entry control module will send a serial data message to the Body Control Module to command the door or doors to be unlocked.

The passive door unlocking feature can be cycled between enabled and disabled using the key fob. The feature also may be turned on or off, or only the driver’s door or all doors can be selected to unlock, in the Settings > Vehicle > Remote Lock, Unlock, Start menu. (Fig. 24)

If the passive door unlocking feature is disabled, the doors will not unlock when pressing any door handle button, or the tailgate will remain locked when pressing the tailgate release, and the turn signals will flash quickly four times.

 

Fig. 24

 

Passive Unlocking Enable

To enable the unlocking feature if it is currently disabled, with the vehicle off, press and hold the Lock and Unlock buttons on the key fob for three seconds. The turn signals will flash four times to indicate that passive unlocking is now enabled.

With passive unlocking enabled, the doors will unlock when pressing the button on the door handle. On the driver’s door, press the button once to unlock only the driver’s door and press it a second time to unlock all doors, depending on the vehicle setting (if equipped).

 

Passive Unlocking Disable

To disable the unlocking feature, with the vehicle off, press and hold the Lock and Unlock buttons on the key fob (Fig. 25) for three seconds. The turn signals will flash four times to indicate that passive unlocking is now disabled.

With passive unlocking disabled, the doors will remain locked when pressing the button on the door handle.

 

Fig. 25

 

If there is a concern with the operation of the passive unlocking system, the system may have been disabled inadvertently. Demonstrate to customers how the system can be enabled and disabled so they are aware of how it operates for future use.

 

– Thanks to Bob Wittmann

 

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