diff --git a/firmware/CHANGELOG.md b/firmware/CHANGELOG.md
index c759e7021e..79ddeb84e9 100644
--- a/firmware/CHANGELOG.md
+++ b/firmware/CHANGELOG.md
@@ -34,6 +34,7 @@ All notable user-facing or behavior-altering changes will be documented in this
  - Toyota 4-1 VVT trigger
  - use extra RAM for lua if your microRusEFI unit has stm32f42x microcontroller 
  - VVT activation delay #3443
+ - ECU uptime into critical error message 
 
 ## March 2022 Release - "Day 22"
 
diff --git a/firmware/console/binary/tunerstudio.cpp b/firmware/console/binary/tunerstudio.cpp
index 63490d653c..d5f4e37083 100644
--- a/firmware/console/binary/tunerstudio.cpp
+++ b/firmware/console/binary/tunerstudio.cpp
@@ -433,7 +433,11 @@ static void handleTestCommand(TsChannelBase* tsChannel) {
 	tsChannel->write((const uint8_t*)testOutputBuffer, strlen(testOutputBuffer));
 
 	if (hasFirmwareError()) {
-		const char* error = getCriticalErrorMessage();
+		char* error = getCriticalErrorMessage();
+		extern int firmwareErrorUptimePosition;
+		if (firmwareErrorUptimePosition > 0) {
+			itoa10(error + firmwareErrorUptimePosition, getTimeNowSeconds());
+		}
 		chsnprintf(testOutputBuffer, sizeof(testOutputBuffer), "error=%s\r\n", error);
 		tsChannel->write((const uint8_t*)testOutputBuffer, strlen(testOutputBuffer));
 	}
diff --git a/firmware/controllers/core/error_handling.cpp b/firmware/controllers/core/error_handling.cpp
index fbcc61a658..158de519b7 100644
--- a/firmware/controllers/core/error_handling.cpp
+++ b/firmware/controllers/core/error_handling.cpp
@@ -22,7 +22,12 @@ bool hasFirmwareErrorFlag = false;
 const char *dbg_panic_file;
 int dbg_panic_line;
 
-const char* getCriticalErrorMessage(void) {
+/**
+ * position at which we would be dynamically appending uptime
+ */
+int firmwareErrorUptimePosition = -1;
+
+char* getCriticalErrorMessage(void) {
 	return criticalErrorMessageBuffer;
 }
 
@@ -220,10 +225,17 @@ void firmwareError(obd_code_e code, const char *fmt, ...) {
 
 	int errorMessageSize = strlen((char*)criticalErrorMessageBuffer);
 	static char versionBuffer[32];
-	chsnprintf(versionBuffer, sizeof(versionBuffer), " %d@%s", getRusEfiVersion(), FIRMWARE_ID);
+	chsnprintf(versionBuffer, sizeof(versionBuffer), "\n%d@%s\nup=",
+			getRusEfiVersion(),
+			FIRMWARE_ID);
 
-	if (errorMessageSize + strlen(versionBuffer) < sizeof(criticalErrorMessageBuffer)) {
+#define MAX_UPTIME_LEN 9
+	int versionBufferLength = strlen(versionBuffer);
+	if (errorMessageSize + versionBufferLength + MAX_UPTIME_LEN < sizeof(criticalErrorMessageBuffer)) {
 		strcpy((char*)(criticalErrorMessageBuffer) + errorMessageSize, versionBuffer);
+		firmwareErrorUptimePosition = errorMessageSize + versionBufferLength;
+	} else {
+		firmwareErrorUptimePosition = -1;
 	}
 
 #else
diff --git a/firmware/controllers/core/error_handling.h b/firmware/controllers/core/error_handling.h
index 9776c5e4d8..8ea76ff8ac 100644
--- a/firmware/controllers/core/error_handling.h
+++ b/firmware/controllers/core/error_handling.h
@@ -37,7 +37,7 @@ extern bool hasFirmwareErrorFlag;
 
 #define hasFirmwareError() hasFirmwareErrorFlag
 
-const char* getCriticalErrorMessage(void);
+char* getCriticalErrorMessage(void);
 const char* getWarningMessage(void);
 
 // todo: better place for this shared declaration?