diff --git a/selfdrive/controls/controlsd.py b/selfdrive/controls/controlsd.py
index 5e91138..1f330e2 100755
--- a/selfdrive/controls/controlsd.py
+++ b/selfdrive/controls/controlsd.py
@@ -88,9 +88,18 @@ class Controls:
     # exiting park, stay in keepalive-tick mode until SubMaster reports
     # everything healthy again, with an 8-second hard cap so we never get
     # stuck if some service is permanently broken.
+    #
+    # Park mode is suppressed for the first 10 seconds after init completes:
+    # card.initialize() runs in data_sample's not-initialized branch and is
+    # what hooks up CarInterface so controls_update actually generates CAN
+    # messages. If we entered park mode before that, the "heartbeat" would
+    # be silent — and only_onroad_active processes would never get a chance
+    # to come up cleanly the first time.
     self.park_mode = False
     self.park_exit_frame = -1
+    self.startup_complete_frame = -1
     self.PARK_GRACE_MAX_FRAMES = int(8.0 / DT_CTRL)
+    self.PARK_STARTUP_DELAY_FRAMES = int(10.0 / DT_CTRL)
 
     self.radarless_model = self.params.get("Model", encoding='utf-8') in RADARLESS_MODELS
 
@@ -1259,9 +1268,24 @@ class Controls:
     if (len(CS.buttonEvents) > 0):
       print (CS.buttonEvents)
 
+  def _park_mode_allowed(self):
+    # Don't allow park mode until init has completed AND we've run at least
+    # 10s of normal step() after init. card.initialize() (which hooks
+    # CarInterface up to send CAN) only runs on the init path, so we need
+    # to take that path at least once before short-circuiting into the
+    # minimal tick. The 10s buffer also lets only_onroad_active processes
+    # come up cleanly the first time before we ask manager to pause them.
+    if not self.initialized:
+      return False
+    if self.startup_complete_frame < 0:
+      self.startup_complete_frame = self.sm.frame
+    return (self.sm.frame - self.startup_complete_frame) >= self.PARK_STARTUP_DELAY_FRAMES
+
   def _update_park_mode(self, CS):
     # CLEARPILOT: track the gear-park flag and write ParkMode for manager.
     # On park→drive transition, capture the frame so the grace window starts.
+    if not self._park_mode_allowed():
+      return
     in_park = CS.gearShifter == GearShifter.park
     if in_park != self.park_mode:
       self.park_mode = in_park