diff --git a/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehicleApPowerStateShutdownParam.aidl b/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehicleApPowerStateShutdownParam.aidl
index 923d42aef1..966ff65d88 100644
--- a/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehicleApPowerStateShutdownParam.aidl
+++ b/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehicleApPowerStateShutdownParam.aidl
@@ -20,33 +20,41 @@ package android.hardware.automotive.vehicle;
 @Backing(type="int")
 enum VehicleApPowerStateShutdownParam {
     /**
-     * AP must shutdown immediately. Postponing is not allowed.
+     * AP must shutdown without Garage mode. Postponing is not allowed.
+     * If AP need to shutdown as soon as possible, EMERGENCY_SHUTDOWN shall be used.
      */
     SHUTDOWN_IMMEDIATELY = 1,
     /**
      * AP can enter deep sleep instead of shutting down completely.
+     * AP can postpone entering deep sleep to run Garage mode.
      */
     CAN_SLEEP = 2,
     /**
-     * AP can only shutdown with postponing allowed.
+     * AP can only shutdown.
+     * AP can postpone shutdown to run Garage mode.
      */
     SHUTDOWN_ONLY = 3,
     /**
-     * AP may enter deep sleep, but must either sleep or shut down immediately.
+     * AP can enter deep sleep, without Garage mode.
      * Postponing is not allowed.
+     * Depending on the actual implementation, it may shut down immediately
      */
     SLEEP_IMMEDIATELY = 4,
     /**
-     * AP must hibernate (suspend to disk) immediately. Postponing is not allowed.
-     * Depending on the actual implementation, it may shut down immediately
+     * AP can hibernate (suspend to disk) without Garage mode.
+     * Postponing is not allowed.
+     * Depending on the actual implementation, it may shut down immediately.
      */
     HIBERNATE_IMMEDIATELY = 5,
     /**
      * AP can enter hibernation (suspend to disk) instead of shutting down completely.
+     * AP can postpone hibernation to run Garage mode.
      */
     CAN_HIBERNATE = 6,
     /**
-     * AP must shutdown (gracefully) without a delay.
+     * AP must shutdown (gracefully) without a delay. AP cannot run Garage mode.
+     * This type must be used only in critical situations when AP must shutdown as soon as possible.
+     * CarService will only notify listeners, but will not wait for completion reports.
      */
     EMERGENCY_SHUTDOWN = 7,
 }