diff --git a/ECU/Application/Inc/StateData.h b/ECU/Application/Inc/StateData.h
index 6ac3ebe94..ece6e9844 100644
--- a/ECU/Application/Inc/StateData.h
+++ b/ECU/Application/Inc/StateData.h
@@ -54,6 +54,7 @@ typedef volatile struct ECU_StateData {
 
 	float min_amk_heat_cap_throttle_percent;
 	float ts_voltage;
+	float glv_voltage_20V;
 	float max_cell_temp_c; /** Temperature of hottest cell, celsius */
 
 	float vehicle_speed_mph; /** Vehicle speed, MPH */
@@ -62,10 +63,8 @@ typedef volatile struct ECU_StateData {
 	float rr_wheel_rpm;	 /** RRv wheel, RPM */
 	float rl_wheel_rpm;	 /** RL wheel, RPM */
 
-	// 0.5V when things go to shit (X_OK low) (BAD)
-	// 3V when things almost poggers (X_OK high but SDC not reset) (BAD)
-	// 2.4V when things are actually poggers (X_OK high and SDC is not triggered)
-	float ams_sense;
+
+	float bms_sense;
 	float imd_sense;
 	float bspd_sense;
 
diff --git a/ECU/Application/Inc/StateUtils.h b/ECU/Application/Inc/StateUtils.h
index 0be6ed429..34bcee8a6 100644
--- a/ECU/Application/Inc/StateUtils.h
+++ b/ECU/Application/Inc/StateUtils.h
@@ -69,8 +69,17 @@ uint32_t MillisecondsSinceBoot(void);
  */
 #define RATE_LIMIT_10_HZ(x, y) (x - y > 100)
 
+typedef enum {
+    SDC_OK,
+    SDC_ONGOING_FAILURE,
+    SDC_LATCHED_FAILURE
+} SDC_Level;
+
 // Checks stateData for critical errors
 bool CriticalError(volatile const ECU_StateData *stateData);
+SDC_Level bmsLevel(volatile const ECU_StateData *stateData);
+SDC_Level imdLevel(volatile const ECU_StateData *stateData);
+SDC_Level bspdLevel(volatile const ECU_StateData *stateData);
 bool bmsFailure(volatile const ECU_StateData *stateData);
 bool imdFailure(volatile const ECU_StateData *stateData);
 bool bspdFailure(volatile const ECU_StateData *stateData);
diff --git a/ECU/Application/Src/CANdler.c b/ECU/Application/Src/CANdler.c
index 7e9b271af..6875b3d74 100644
--- a/ECU/Application/Src/CANdler.c
+++ b/ECU/Application/Src/CANdler.c
@@ -80,6 +80,7 @@ void ECU_CAN_MessageHandler(ECU_StateData *state_data, GRCAN_BUS_ID bus_id, GRCA
 			state_data->ir_minus = GETBIT(acu_status_2->precharge_latch_flags, 4);
 			state_data->ir_plus = GETBIT(acu_status_2->precharge_latch_flags, 5);
 			state_data->acu_software_latch = GETBIT(acu_status_2->precharge_latch_flags, 6);
+			state_data->glv_voltage_20V = acu_status_2->_20v_voltage * 0.1f;
 			break;
 
 		case GRCAN_INV_STATUS_1:
diff --git a/ECU/Application/Src/CANutils.c b/ECU/Application/Src/CANutils.c
index 4f1a04898..ea78cffb6 100644
--- a/ECU/Application/Src/CANutils.c
+++ b/ECU/Application/Src/CANutils.c
@@ -130,7 +130,6 @@ void SendECUAnalogDataOverCAN(ECU_StateData *stateData)
 	uint32_t millis_since_boot = MillisecondsSinceBoot();
 
 	static uint32_t last_can_tcm_request_millis = 0;
-
 	if (millis_since_boot - last_can_tcm_request_millis > 100) {
 		GRCAN_ECU_ANALOG_DATA_MSG message = {.bspd_signal = stateData->bspd_signal,
 						     .bse_signal = stateData->bse_signal,
diff --git a/ECU/Application/Src/Lights.c b/ECU/Application/Src/Lights.c
index 12817b010..f12effd15 100644
--- a/ECU/Application/Src/Lights.c
+++ b/ECU/Application/Src/Lights.c
@@ -18,11 +18,35 @@ void BrakeLightControl(ECU_StateData *stateLump)
 	}
 }
 
+static bool SDCStartupCondition = true; // prevent false positive TSSI on startup
+// PRECONDITION: IMD assumed to give valid readings before this is run
 void TSSILightControl(ECU_StateData *stateLump)
 {
 	// EV.5.11.5: Flash, 2 Hz to 5 Hz, 50% duty cycle
 	//     Here we chose a period of 286ms
-	if (stateLump->tssi_fault) {
+
+	bool redCar;
+
+	// if we are before SDC is reset, don't red car unless there is an active failure
+	if (SDCStartupCondition) {
+		redCar = false;
+
+		SDC_Level bms = bmsLevel(stateLump);
+		SDC_Level imd = imdLevel(stateLump);
+
+		if (bms == SDC_OK && imd == SDC_OK) {
+			SDCStartupCondition = false;
+		} else if (bms == SDC_ONGOING_FAILURE || imd == SDC_ONGOING_FAILURE) {
+			SDCStartupCondition = false;
+			redCar = true;
+		}
+	} else {
+		redCar = bmsFailure(stateLump) || imdFailure(stateLump);
+	}
+
+
+	// if red car blink tssi
+	if (redCar) {
 		LL_GPIO_ResetOutputPin(TSSI_G_CONTROL_GPIO_Port, TSSI_G_CONTROL_Pin);
 		if (MillisecondsSinceBoot() % 286 < 143) {
 			LL_GPIO_SetOutputPin(TSSI_R_CONTROL_GPIO_Port, TSSI_R_CONTROL_Pin);
diff --git a/ECU/Application/Src/StateTicks.c b/ECU/Application/Src/StateTicks.c
index 586dd056e..e3efbf94b 100644
--- a/ECU/Application/Src/StateTicks.c
+++ b/ECU/Application/Src/StateTicks.c
@@ -26,7 +26,7 @@
  * @remark Intentionally not a globally accessible variable
  */
 
-ECU_StateData stateLump = {.ecu_state = GR_GLV_ON, .acu_software_latch = 1, .powerlevel = 3};
+ECU_StateData stateLump = {.ecu_state = GR_GLV_ON, .acu_software_latch = 1, .glv_voltage_20V = 20.0f, .powerlevel = 3};
 
 static uint32_t millis_since_boot;
 void ECU_State_Tick(void)
@@ -39,27 +39,6 @@ void ECU_State_Tick(void)
 		last_ECU_status_msg_millis = millis_since_boot;
 	}
 
-	// light control
-	//  false or imd_sense  > 0.5 -> false -> no light
-	//  false or imd_sense < 0.5 -> true -> light
-	//  true or imd_sense > 0.5 -> true -> light stays on
-	//  stateLump.bms_light |= !(stateLump.ams_sense > 0.5f);
-	//  stateLump.imd_light |= !(stateLump.imd_sense > 0.5f);
-	// lgoht control reset
-
-	// true and no failiure -> flase
-	// true and failiure -> true
-	// false and failure -> false
-	// flase and no failure -> false
-	// stateLump.bms_light &= (bmsFailure(&stateLump));
-	// stateLump.imd_light &= (imdFailure(&stateLump));
-
-	stateLump.bms_light = (stateLump.ams_sense <= 0.4f) || (stateLump.bms_light && bmsFailure(&stateLump));
-	stateLump.imd_light = (stateLump.imd_sense <= 0.4f) || (stateLump.imd_light && imdFailure(&stateLump));
-
-	stateLump.tssi_fault = stateLump.bms_light || stateLump.imd_light;
-
-	// bmsFailure(&stateLump) || imdFailure(&stateLump);
 
 	if (stateLump.ts_active_button_press_interrupt) {
 		stateLump.ts_active_button_press_interrupt = false;
diff --git a/ECU/Application/Src/StateUtils.c b/ECU/Application/Src/StateUtils.c
index efef6b4a0..260a52309 100644
--- a/ECU/Application/Src/StateUtils.c
+++ b/ECU/Application/Src/StateUtils.c
@@ -58,9 +58,43 @@ bool CriticalError(volatile const ECU_StateData *stateData)
 	return problem;
 }
 
+SDC_Level bmsLevel(volatile const ECU_StateData *stateData) {
+	// TODO: DYNAMIC LOGIC HERE
+	if (stateData->bms_sense < 0.2f) {
+		return SDC_ONGOING_FAILURE;
+	} else if (stateData->bms_sense > 1.6f) {
+		return SDC_LATCHED_FAILURE;
+	}
+
+	return SDC_OK;
+}
+
+SDC_Level imdLevel(volatile const ECU_StateData *stateData) {
+	// TODO: DYNAMIC LOGIC HERE
+	if (stateData->imd_sense < 0.2f) {
+		return SDC_ONGOING_FAILURE;
+	} else if (stateData->imd_sense > 1.6f) {
+		return SDC_LATCHED_FAILURE;
+	}
+
+	return SDC_OK;
+}
+
+SDC_Level bspdLevel(volatile const ECU_StateData *stateData) {
+	if (stateData->bspd_sense < 0.6f) {
+		return SDC_ONGOING_FAILURE;
+	} else if (stateData->bspd_sense > 1.35f) {
+		return SDC_LATCHED_FAILURE;
+	}
+
+	return SDC_OK;
+}
+
+
 bool bmsFailure(volatile const ECU_StateData *stateData)
 {
-	return stateData->ams_sense < 0.5f || stateData->ams_sense > 1.6f; // 0.5 to 1.6 is valid
+	SDC_Level level = bmsLevel(stateData);
+	return level == SDC_ONGOING_FAILURE || level == SDC_LATCHED_FAILURE;
 }
 
 bool imdFailure(volatile const ECU_StateData *stateData)
@@ -71,16 +105,14 @@ bool imdFailure(volatile const ECU_StateData *stateData)
 		return false;
 	}
 
-	return stateData->imd_sense < 0.5f || stateData->imd_sense > 1.6f; // 0.5 to 1.6 is valid
+	SDC_Level level = imdLevel(stateData);
+	return level == SDC_ONGOING_FAILURE || level == SDC_LATCHED_FAILURE;
 }
 
 bool bspdFailure(volatile const ECU_StateData *stateData)
 {
-#ifdef PLAN_C
-	return false;
-#endif
-
-	return stateData->bspd_sense < 0.6f || stateData->bspd_sense > 1.35f; // possible values are 0.3, 1.2, 1.6
+	SDC_Level level = bspdLevel(stateData);
+	return level == SDC_ONGOING_FAILURE || level == SDC_LATCHED_FAILURE;
 }
 
 bool APPS_BSE_Violation(volatile const ECU_StateData *stateData)
diff --git a/ECU/Core/Src/main.c b/ECU/Core/Src/main.c
index 8e9fc3bea..422752064 100644
--- a/ECU/Core/Src/main.c
+++ b/ECU/Core/Src/main.c
@@ -209,7 +209,7 @@ void write_adc_values_to_state_data(void)
 	// TODO: determine conversion factors for all of these (uint to float)
 	stateLump.bspd_sense = ADC_outputs[ADC_BUFFER_SENSE_BSPD] / 4095.0 * 3.3;
 	stateLump.imd_sense = ADC_outputs[ADC_BUFFER_SENSE_IMD] / 4095.0 * 3.3;
-	stateLump.ams_sense = ADC_outputs[ADC_BUFFER_SENSE_AMS] / 4095.0 * 3.3;
+	stateLump.bms_sense = ADC_outputs[ADC_BUFFER_SENSE_AMS] / 4095.0 * 3.3;
 }
 
 void ADC_Configure(void)
@@ -540,7 +540,7 @@ int main(void)
 			// ADC_Logomatic();
 		}
 	}
-	/* USER CODE END 3 */
+/* USER CODE END 3 */
 }
 
 /**