just calculate in function

selfdrive/car/ford/carcontroller.py

@@ -85,16 +85,14 @@ class CarController:
       if CC.longActive:
         accel = clip(actuators.accel, CarControllerParams.ACCEL_MIN, CarControllerParams.ACCEL_MAX)
         gas = accel
-        decel = accel < 0.0
         if accel < -0.5:
           gas = -5.0
       else:
         accel = 0.0  # -0.0008 m/s^2 on CAN
         gas = -5.0
-        decel = False
 
       stopping = CC.actuators.longControlState == LongCtrlState.stopping
-      can_sends.append(create_acc_msg(self.packer, CC.longActive, gas, accel, decel, stopping))
+      can_sends.append(create_acc_msg(self.packer, CC.longActive, gas, accel, stopping))
 
     ### ui ###
     send_ui = (self.main_on_last != main_on) or (self.lkas_enabled_last != CC.latActive) or (self.steer_alert_last != steer_alert)

selfdrive/car/ford/fordcan.py

@@ -101,7 +101,7 @@ def create_lat_ctl2_msg(packer, mode: int, path_offset: float, path_angle: float
   return packer.make_can_msg("LateralMotionControl2", CANBUS.main, values)
 
 
-def create_acc_msg(packer, long_active: bool, gas: float, accel: float, decel: bool, stopping: bool):
+def create_acc_msg(packer, long_active: bool, gas: float, accel: float, stopping: bool):
   """
   Creates a CAN message for the Ford ACC Command.
 
@@ -111,6 +111,7 @@ def create_acc_msg(packer, long_active: bool, gas: float, accel: float, decel: b
   Frequency is 50Hz.
   """
 
+  decel = 1 if accel < 0 and long_active else 0
   values = {
     "AccBrkTot_A_Rq": accel,                          # Brake total accel request: [-20|11.9449] m/s^2
     "Cmbb_B_Enbl": 1 if long_active else 0,           # Enabled: 0=No, 1=Yes