diff --git a/panda/board/safety.h b/panda/board/safety.h
index 88f708e..3600ab2 100644
--- a/panda/board/safety.h
+++ b/panda/board/safety.h
@@ -275,7 +275,7 @@ void generic_rx_checks(bool stock_ecu_detected) {
   regen_braking_prev = regen_braking;
 
   // check if stock ECU is on bus broken by car harness
-  if ((safety_mode_cnt > RELAY_TRNS_TIMEOUT) && stock_ecu_detected) {
+  if ((safety_mode_cnt > RELAY_TRNS_TIMEOUT) && stock_ecu_detected && !gm_skip_relay_check) {
     relay_malfunction_set();
   }
 }
diff --git a/panda/board/safety/safety_gm.h b/panda/board/safety/safety_gm.h
index f1073ab..c636a3e 100644
--- a/panda/board/safety/safety_gm.h
+++ b/panda/board/safety/safety_gm.h
@@ -66,6 +66,7 @@ const uint16_t GM_PARAM_HW_CAM_LONG = 2;
 const uint16_t GM_PARAM_HW_SDGM = 4;
 const uint16_t GM_PARAM_CC_LONG = 8;
 const uint16_t GM_PARAM_HW_ASCM_LONG = 16;
+const uint16_t GM_PARAM_NO_CAMERA = 32;
 const uint16_t GM_PARAM_NO_ACC = 64;
 const uint16_t GM_PARAM_PEDAL_LONG = 128;  // TODO: this can be inferred
 const uint16_t GM_PARAM_PEDAL_INTERCEPTOR = 256;
@@ -83,6 +84,7 @@ bool gm_pcm_cruise = false;
 bool gm_has_acc = true;
 bool gm_pedal_long = false;
 bool gm_cc_long = false;
+bool gm_skip_relay_check = false;
 bool gm_force_ascm = false;
 
 static void handle_gm_wheel_buttons(const CANPacket_t *to_push) {
diff --git a/panda/python/__init__.py b/panda/python/__init__.py
index d4eba58..fcc4e2b 100644
--- a/panda/python/__init__.py
+++ b/panda/python/__init__.py
@@ -237,6 +237,7 @@ class Panda:
   FLAG_GM_HW_SDGM = 4
   FLAG_GM_CC_LONG = 8
   FLAG_GM_HW_ASCM_LONG = 16
+  FLAG_GM_NO_CAMERA = 32
   FLAG_GM_NO_ACC = 64
   FLAG_GM_PEDAL_LONG = 128
   FLAG_GM_GAS_INTERCEPTOR = 256
diff --git a/selfdrive/car/gm/carstate.py b/selfdrive/car/gm/carstate.py
index 7b84784..3588ec9 100644
--- a/selfdrive/car/gm/carstate.py
+++ b/selfdrive/car/gm/carstate.py
@@ -49,7 +49,7 @@ class CarState(CarStateBase):
     self.loopback_lka_steering_cmd_updated = len(loopback_cp.vl_all["ASCMLKASteeringCmd"]["RollingCounter"]) > 0
     if self.loopback_lka_steering_cmd_updated:
       self.loopback_lka_steering_cmd_ts_nanos = loopback_cp.ts_nanos["ASCMLKASteeringCmd"]["RollingCounter"]
-    if self.CP.networkLocation == NetworkLocation.fwdCamera:
+    if self.CP.networkLocation == NetworkLocation.fwdCamera and not self.CP.flags & GMFlags.NO_CAMERA.value:
       self.pt_lka_steering_cmd_counter = pt_cp.vl["ASCMLKASteeringCmd"]["RollingCounter"]
       self.cam_lka_steering_cmd_counter = cam_cp.vl["ASCMLKASteeringCmd"]["RollingCounter"]
 
@@ -69,7 +69,10 @@ class CarState(CarStateBase):
     else:
       ret.gearShifter = self.parse_gear_shifter(self.shifter_values.get(pt_cp.vl["ECMPRDNL2"]["PRNDL2"], None))
 
-    ret.brake = pt_cp.vl["ECMAcceleratorPos"]["BrakePedalPos"]
+    if self.CP.flags & GMFlags.NO_ACCELERATOR_POS_MSG.value:
+      ret.brake = pt_cp.vl["EBCMBrakePedalPosition"]["BrakePedalPosition"] / 0xd0
+    else:
+      ret.brake = pt_cp.vl["ECMAcceleratorPos"]["BrakePedalPos"]
     if self.CP.networkLocation == NetworkLocation.fwdCamera:
       ret.brakePressed = pt_cp.vl["ECMEngineStatus"]["BrakePressed"] != 0
     else:
@@ -136,7 +139,7 @@ class CarState(CarStateBase):
 
     ret.cruiseState.enabled = pt_cp.vl["AcceleratorPedal2"]["CruiseState"] != AccState.OFF
     ret.cruiseState.standstill = pt_cp.vl["AcceleratorPedal2"]["CruiseState"] == AccState.STANDSTILL
-    if self.CP.networkLocation == NetworkLocation.fwdCamera:
+    if self.CP.networkLocation == NetworkLocation.fwdCamera and not self.CP.flags & GMFlags.NO_CAMERA.value:
       if self.CP.carFingerprint not in CC_ONLY_CAR:
         ret.cruiseState.speed = cam_cp.vl["ASCMActiveCruiseControlStatus"]["ACCSpeedSetpoint"] * CV.KPH_TO_MS
       if self.CP.carFingerprint not in SDGM_CAR:
@@ -175,7 +178,7 @@ class CarState(CarStateBase):
   @staticmethod
   def get_cam_can_parser(CP):
     messages = []
-    if CP.networkLocation == NetworkLocation.fwdCamera:
+    if CP.networkLocation == NetworkLocation.fwdCamera and not CP.flags & GMFlags.NO_CAMERA.value:
       messages += [
         ("ASCMLKASteeringCmd", 10),
       ]
@@ -235,6 +238,9 @@ class CarState(CarStateBase):
       messages += [
         ("ASCMLKASteeringCmd", 0),
       ]
+      if CP.flags & GMFlags.NO_ACCELERATOR_POS_MSG.value:
+        messages.remove(("ECMAcceleratorPos", 80))
+        messages.append(("EBCMBrakePedalPosition", 100))
 
     if CP.transmissionType == TransmissionType.direct:
       messages += [
diff --git a/selfdrive/car/gm/interface.py b/selfdrive/car/gm/interface.py
index af39160..d8a0a6b 100644
--- a/selfdrive/car/gm/interface.py
+++ b/selfdrive/car/gm/interface.py
@@ -23,6 +23,8 @@ BUTTONS_DICT = {CruiseButtons.RES_ACCEL: ButtonType.accelCruise, CruiseButtons.D
 FrogPilotEventName = custom.FrogPilotEvents
 
 ACCELERATOR_POS_MSG = 0xbe
+CAM_MSG = 0x320  # AEBCmd
+                 # TODO: Is this always linked to camera presence?
 PEDAL_MSG = 0x201
 
 NON_LINEAR_TORQUE_PARAMS = {
@@ -376,6 +378,11 @@ class CarInterface(CarInterfaceBase):
     if candidate in CC_ONLY_CAR:
       ret.safetyConfigs[0].safetyParam |= Panda.FLAG_GM_NO_ACC
 
+    # Exception for flashed cars, or cars whose camera was removed
+    if (ret.networkLocation == NetworkLocation.fwdCamera or candidate in CC_ONLY_CAR) and CAM_MSG not in fingerprint[CanBus.CAMERA] and not candidate in SDGM_CAR:
+      ret.flags |= GMFlags.NO_CAMERA.value
+      ret.safetyConfigs[0].safetyParam |= Panda.FLAG_GM_NO_CAMERA
+
     if ACCELERATOR_POS_MSG not in fingerprint[CanBus.POWERTRAIN]:
       ret.flags |= GMFlags.NO_ACCELERATOR_POS_MSG.value
 
diff --git a/selfdrive/car/gm/values.py b/selfdrive/car/gm/values.py
index eab288b..e74bf3b 100644
--- a/selfdrive/car/gm/values.py
+++ b/selfdrive/car/gm/values.py
@@ -1,6 +1,6 @@
 from collections import defaultdict
 from dataclasses import dataclass
-from enum import Enum, StrEnum
+from enum import Enum, IntFlag, StrEnum
 from typing import Dict, List, Union
 
 from cereal import car
@@ -181,6 +181,7 @@ class CanBus:
 class GMFlags(IntFlag):
   PEDAL_LONG = 1
   CC_LONG = 2
+  NO_CAMERA = 4
   NO_ACCELERATOR_POS_MSG = 8