diff --git a/ECU/Application/Inc/Pinging.h b/ECU/Application/Inc/Pinging.h
new file mode 100644
index 00000000..97e7ca16
--- /dev/null
+++ b/ECU/Application/Inc/Pinging.h
@@ -0,0 +1,13 @@
+#include <stdint.h>
+
+#ifndef PINGING_H
+#define PINGING_H
+
+#define PINGTIMEOUT_TIME 250U		  // time in ms before a ping is considered timed out
+#define PINGTIMEOUT_VALUE (UINT8_MAX - 1) // return time value representing a timed out ping
+
+void pingAll(void);				       // ping all IDs specified, to be run every PINGTIMEOUT_TIME milliseconds
+uint32_t getRTT(uint8_t id);			       // get latest RTT by ID
+void respondToPing(uint8_t srcID, uint32_t timestamp); // "callback"
+
+#endif
diff --git a/ECU/Application/Src/CANdler.c b/ECU/Application/Src/CANdler.c
index cd12c47e..f00fa29e 100644
--- a/ECU/Application/Src/CANdler.c
+++ b/ECU/Application/Src/CANdler.c
@@ -6,6 +6,7 @@
 #include "GR_OLD_MSG_ID.h"
 #include "GR_OLD_NODE_ID.h"
 #include "Logomatic.h"
+#include "Pinging.h"
 #include "StateData.h"
 #include "bitManipulations.h"
 
@@ -48,7 +49,7 @@ void ECU_CAN_MessageHandler(ECU_StateData *state_data, GR_OLD_BUS_ID bus_id, GR_
 				ReportBadMessageLength(bus_id, msg_id, sender_id);
 				break;
 			}
-			// TODO See Issue #143
+			respondToPing(sender_id, ((GR_OLD_PING_MSG *)data)->timestamp);
 			break;
 
 		case MSG_BCU_STATUS_1:
diff --git a/ECU/Application/Src/Pinging.c b/ECU/Application/Src/Pinging.c
new file mode 100644
index 00000000..858c41df
--- /dev/null
+++ b/ECU/Application/Src/Pinging.c
@@ -0,0 +1,58 @@
+#include "Pinging.h"
+
+#include "CANutils.h"
+#include "GR_OLD_MSG_DAT.h"
+#include "GR_OLD_MSG_ID.h"
+#include "GR_OLD_NODE_ID.h"
+#include "StateUtils.h"
+
+// add new pingable devices here, arrays are updated automagically
+#define PING_LIST(X)                                                                                                                                                                                   \
+	X(GR_BCU, 0)                                                                                                                                                                                   \
+	X(GR_DASH_PANEL, 1)                                                                                                                                                                            \
+	X(GR_CCU, 2)
+
+const uint8_t IDsToBePinged[] = {
+#define AS_ID(id, idx) id,
+    PING_LIST(AS_ID)};
+
+const uint8_t PingsToBeIDed[] = {
+#define AS_LOOKUP(id, idx) [id] = idx,
+    PING_LIST(AS_LOOKUP)};
+
+#define NUMBER_OF_PING_DEVICES (sizeof(IDsToBePinged) / sizeof(IDsToBePinged[0]))
+
+static volatile uint32_t sentTimestamps[NUMBER_OF_PING_DEVICES];
+static volatile uint32_t receivedTimestamps[NUMBER_OF_PING_DEVICES];
+static uint8_t RTTs[NUMBER_OF_PING_DEVICES];
+
+void pingAll(void)
+{
+	for (uint8_t i = 0; i < NUMBER_OF_PING_DEVICES; i++) {
+		uint32_t timestamp = MillisecondsSinceBoot();
+
+		if (receivedTimestamps[i] >= sentTimestamps[i]) {
+			// no timeout
+			RTTs[i] = receivedTimestamps[i] - sentTimestamps[i];
+		} else {
+			// timeout
+			RTTs[i] = PINGTIMEOUT_VALUE;
+		}
+
+		sentTimestamps[i] = timestamp;
+		ECU_CAN_Send(GR_OLD_BUS_PRIMARY, IDsToBePinged[i], MSG_PING, &(GR_OLD_PING_MSG){timestamp}, sizeof(GR_OLD_PING_MSG));
+	}
+}
+
+uint32_t getRTT(uint8_t ID)
+{
+	return RTTs[PingsToBeIDed[ID]];
+}
+
+void respondToPing(uint8_t srcID, uint32_t timestamp)
+{
+	uint8_t index = PingsToBeIDed[srcID];
+	if (timestamp == sentTimestamps[index]) {
+		receivedTimestamps[index] = MillisecondsSinceBoot();
+	}
+}
diff --git a/ECU/CMakeLists.txt b/ECU/CMakeLists.txt
index 26953c93..41327e2a 100644
--- a/ECU/CMakeLists.txt
+++ b/ECU/CMakeLists.txt
@@ -77,6 +77,7 @@ target_sources(
 		Application/Src/StateTicks.c
 		Application/Src/StateUtils.c
 		Application/Src/CANutils.c
+		Application/Src/Pinging.c
 		Application/Src/Lights.c
 )
 
diff --git a/ECU/Core/Src/main.c b/ECU/Core/Src/main.c
index 3457c251..3ea450de 100644
--- a/ECU/Core/Src/main.c
+++ b/ECU/Core/Src/main.c
@@ -35,6 +35,7 @@
 #include "CANutils.h"
 #include "Lights.h"
 #include "Logomatic.h"
+#include "Pinging.h"
 #include "StateTicks.h"
 #include "StateUtils.h"
 #include "adc.h"
@@ -431,15 +432,34 @@ int main(void)
 		/* USER CODE END WHILE */
 
 		/* USER CODE BEGIN 3 */
+		static uint32_t nextPing;
+		if (MillisecondsSinceBoot() >= nextPing) {
+			pingAll();
+
+			if (nextPing != 0) {
+				if (getRTT(GR_BCU) == PINGTIMEOUT_VALUE) {
+					LOGOMATIC("ERROR: BCU is not responding to pings!\n");
+				}
+				if (getRTT(GR_DASH_PANEL) == PINGTIMEOUT_VALUE) {
+					LOGOMATIC("ERROR: Dash Panel is not responding to pings!\n");
+				}
+				if (getRTT(GR_CCU) != PINGTIMEOUT_VALUE) {
+					// halt if CCU is connected
+					return 1;
+				}
+			}
+			nextPing = MillisecondsSinceBoot() + PINGTIMEOUT_TIME;
+		}
+
 		read_digital();
 		// TODO: determine alpha
 		ADC_UpdateAnalogValues_EMA(ADC_buffers, NUM_SIGNALS, 0.3, ADC_outputs);
 		SendECUStateDataOverCAN(&stateLump);
+
 		write_adc_values_to_state_data();
 		ECU_State_Tick();
 		lightControl(&stateLump);
 		LOGOMATIC("Main Loop Tick Complete. I use Arch btw\n");
-		LL_mDelay(250); // FIXME Reduce or remove de
 	}
 	/* USER CODE END 3 */
 }