      ret.radarTimeStep = 0.0667  # GM radar runs at 15Hz instead of standard 20Hz
  
      if candidate == CAR.VOLT:
        ret.mass = 1607. + STD_CARGO_KG
        ret.wheelbase = 2.69
        ret.steerRatio = 17.7  # Stock 15.7, LiveParameters
        tire_stiffness_factor = 0.469  # Stock Michelin Energy Saver A/S, LiveParameters
        ret.centerToFront = ret.wheelbase * 0.45  # Volt Gen 1, TODO corner weigh
  
        ret.lateralTuning.pid.kpBP = [0., 40.]
 
</s> remove       ret.mass = 1363. + STD_CARGO_KG
 </s> add  </s> remove       ret.steerRatio = 17.3
 </s> add  </s> remove       # Handle ACCButtons changing buttons mid-press
 </s> add     # Enabling at a standstill with brake is allowed
    # TODO: verify 17 Volt can enable for the first time at a stop and allow for all GMs
    if ret.vEgo < self.CP.minEnableSpeed and not (ret.standstill and ret.brake >= 20 and
                                                  self.CP.networkLocation == NetworkLocation.fwdCamera):
      ret.radarTimeStep = 0.0667  # GM radar runs at 15Hz instead of standard 20Hz
  
      if candidate == CAR.VOLT:
        ret.mass = 1607. + STD_CARGO_KG

        ret.steerRatio = 17.7  # Stock 15.7, LiveParameters
        tire_stiffness_factor = 0.469  # Stock Michelin Energy Saver A/S, LiveParameters
        ret.centerToFront = ret.wheelbase * 0.45  # Volt Gen 1, TODO corner weigh
  
        ret.lateralTuning.pid.kpBP = [0., 40.]
keep keep keep keep replace keep keep keep keep keep
 GM camera ACC: show under enable speed alert (#26148)

* fix the fault more generically

* fix

* need this

* some clean up

* comment and use standstill

* comment

* add comment

* better fix

* rm

* better (for now)

* update docs 
selfdrive/car/gm/interface.py