diff --git a/selfdrive/car/toyota/carstate.py b/selfdrive/car/toyota/carstate.py
index 6f3b3d3..3b9b85e 100644
--- a/selfdrive/car/toyota/carstate.py
+++ b/selfdrive/car/toyota/carstate.py
@@ -24,6 +24,8 @@ TEMP_STEER_FAULTS = (0, 9, 11, 21, 25)
 # - prolonged high driver torque: 17 (permanent)
 PERM_STEER_FAULTS = (3, 17)
 
+ZSS_THRESHOLD = 4.0
+ZSS_THRESHOLD_COUNT = 10
 
 class CarState(CarStateBase):
   def __init__(self, CP):
@@ -49,6 +51,13 @@ class CarState(CarStateBase):
     self.acc_type = 1
     self.lkas_hud = {}
 
+    # FrogPilot variables
+    self.zss_compute = False
+    self.zss_cruise_active_last = False
+
+    self.zss_angle_offset = 0
+    self.zss_threshold_count = 0
+
   def update(self, cp, cp_cam, frogpilot_variables):
     ret = car.CarState.new_message()
     fp_ret = custom.FrogPilotCarState.new_message()
@@ -180,6 +189,33 @@ class CarState(CarStateBase):
       else:
         self.distance_button = cp.vl["SDSU"]["FD_BUTTON"]
 
+    # FrogPilot carstate functions
+
+    # ZSS Support - Credit goes to the DragonPilot team!
+    if self.CP.flags & ToyotaFlags.ZSS and self.zss_threshold_count < ZSS_THRESHOLD_COUNT:
+      zorro_steer = cp.vl["SECONDARY_STEER_ANGLE"]["ZORRO_STEER"]
+
+      # Only compute ZSS offset when acc is active
+      zss_cruise_active = ret.cruiseState.available
+      if zss_cruise_active and not self.zss_cruise_active_last:
+        self.zss_compute = True  # Cruise was just activated, so allow offset to be recomputed
+        self.zss_threshold_count = 0
+      self.zss_cruise_active_last = zss_cruise_active
+
+      # Compute ZSS offset
+      if self.zss_compute:
+        if abs(ret.steeringAngleDeg) > 1e-3 and abs(zorro_steer) > 1e-3:
+          self.zss_compute = False
+          self.zss_angle_offset = zorro_steer - ret.steeringAngleDeg
+
+      # Error check
+      new_steering_angle_deg = zorro_steer - self.zss_angle_offset
+      if abs(ret.steeringAngleDeg - new_steering_angle_deg) > ZSS_THRESHOLD:
+        self.zss_threshold_count += 1
+      else:
+        # Apply offset
+        ret.steeringAngleDeg = new_steering_angle_deg
+
     return ret, fp_ret
 
   @staticmethod
@@ -235,6 +271,8 @@ class CarState(CarStateBase):
         ("SDSU", 100),
       ]
 
+    messages += [("SECONDARY_STEER_ANGLE", 0)]
+
     return CANParser(DBC[CP.carFingerprint]["pt"], messages, 0)
 
   @staticmethod
diff --git a/selfdrive/car/toyota/interface.py b/selfdrive/car/toyota/interface.py
index decae79..13b6b40 100644
--- a/selfdrive/car/toyota/interface.py
+++ b/selfdrive/car/toyota/interface.py
@@ -41,6 +41,9 @@ class CarInterface(CarInterfaceBase):
       ret.steerActuatorDelay = 0.12  # Default delay, Prius has larger delay
       ret.steerLimitTimer = 0.4
 
+      if 0x23 in fingerprint[0]:  # Detect if ZSS is present
+        ret.flags |= ToyotaFlags.ZSS.value
+
     ret.stoppingControl = False  # Toyota starts braking more when it thinks you want to stop
 
     stop_and_go = candidate in TSS2_CAR
diff --git a/selfdrive/car/toyota/values.py b/selfdrive/car/toyota/values.py
index 9a3e730..e2a519b 100644
--- a/selfdrive/car/toyota/values.py
+++ b/selfdrive/car/toyota/values.py
@@ -59,6 +59,8 @@ class ToyotaFlags(IntFlag):
   # these cars are speculated to allow stop and go when the DSU is unplugged or disabled with sDSU
   SNG_WITHOUT_DSU = 512
 
+  # FrogPilot Toyota flags
+  ZSS = 2048
 
 class Footnote(Enum):
   CAMRY = CarFootnote(