Index: firmware/App/Services/CommBuffers.c
===================================================================
diff -u -r30f049651877229042e3f8700c8596e5b9a1e0f4 -r421ffbd3887d136b66da26ee3eeb17dcd9a773b8
--- firmware/App/Services/CommBuffers.c	(.../CommBuffers.c)	(revision 30f049651877229042e3f8700c8596e5b9a1e0f4)
+++ firmware/App/Services/CommBuffers.c	(.../CommBuffers.c)	(revision 421ffbd3887d136b66da26ee3eeb17dcd9a773b8)
@@ -153,12 +153,6 @@
         // If buffer was full, check persistence - trigger s/w fault if persists
         if ( TRUE == bufferFull )
         {
-#ifdef DEBUG_ENABLED
-            char debugStr[ 100 ];
-            sprintf( debugStr, "Buf OF:#%3d,%3d, %02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X\n", buffer, len, data[0], data[1], data[2], data[3], data[4], data[5], data[6], data[7] );
-            sendDebugData( (U08*)debugStr, strlen(debugStr) );
-            sendDebugDataToUI( (U08*)debugStr );
-#endif
             clearBuffer( buffer );
             // Not first overflow?
             if ( firstBufferOverflowTimeStamp != 0 )
Index: firmware/App/Services/Interrupts.c
===================================================================
diff -u -rd3b7ae356aae29c99cb039713a2e120fdbce5a9c -r421ffbd3887d136b66da26ee3eeb17dcd9a773b8
--- firmware/App/Services/Interrupts.c	(.../Interrupts.c)	(revision d3b7ae356aae29c99cb039713a2e120fdbce5a9c)
+++ firmware/App/Services/Interrupts.c	(.../Interrupts.c)	(revision 421ffbd3887d136b66da26ee3eeb17dcd9a773b8)
@@ -54,14 +54,9 @@
 
 // ********** private data **********
 
-#ifdef DEBUG_ENABLED
-    static U32 sci1FrameErrorCnt = 0;
-    static U32 sci1OverrunErrorCnt = 0;
-#endif
 static U32 sci2FrameErrorCnt = 0;                                       ///< FPGA serial frame error counter.
 static U32 sci2OverrunErrorCnt = 0;                                     ///< FPGA serial overrun error counter.
 
-static U32 can1PassiveCnt = 0;                                          ///< CAN passive mode counter.
 static U32 can1WarningCnt = 0;                                          ///< CAN warning mode counter.
 static U32 can1BusOffCnt = 0;                                           ///< CAN buss off mode counter.
 static U32 can1ParityCnt = 0;                                           ///< CAN parity error counter.
@@ -78,7 +73,6 @@
 void initInterrupts( void )
 {
     // Initialize various time windowed counts for monitoring CAN & UART errors and warnings
-    initTimeWindowedCount( TIME_WINDOWED_COUNT_CAN_PASSIVE, MAX_COMM_ERRORS, COMM_ERROR_TIME_WINDOW_MS );
     initTimeWindowedCount( TIME_WINDOWED_COUNT_CAN_OFF, MAX_COMM_ERRORS, COMM_ERROR_TIME_WINDOW_MS );
     initTimeWindowedCount( TIME_WINDOWED_COUNT_CAN_PARITY, MAX_COMM_ERRORS, COMM_ERROR_TIME_WINDOW_MS );
     initTimeWindowedCount( TIME_WINDOWED_COUNT_FPGA_UART_FRAME_ERROR, MAX_COMM_ERRORS, COMM_ERROR_TIME_WINDOW_MS );
@@ -95,15 +89,6 @@
 void phantomInterrupt(void)
 {
     // TODO - what to do with phantom interrupts?
-#ifdef DEBUG_ENABLED
-    {
-        char debugStr[ 256 ];
-
-        sprintf( debugStr, "HD-phantom interrupt\n" );
-        sendDebugData( (U08*)debugStr, strlen(debugStr) );
-        sendDebugDataToUI( (U08*)debugStr );
-    }
-#endif
 }
 
 /*********************************************************************//**
@@ -171,63 +156,34 @@
  *************************************************************************/
 void canErrorNotification(canBASE_t *node, uint32 notification)
 {
-#ifdef DEBUG_ENABLED
-    char debugStr[ 256 ];
-#endif
-
     if ( node == canREG1 )
-    {
+    {
+        // Parity error - message RAM is corrupted
         if ( notification & canLEVEL_PARITY_ERR )
         {
             can1ParityCnt++;
             if ( TRUE == incTimeWindowedCount( TIME_WINDOWED_COUNT_CAN_PARITY ) )
             {
                 SET_ALARM_WITH_1_U32_DATA( ALARM_ID_HD_SOFTWARE_FAULT, SW_FAULT_ID_CAN_PARITY_ERROR )
             }
-#ifdef DEBUG_ENABLED
-            sprintf( debugStr, "CAN parity error:%5d \n", can1ParityCnt );
-            sendDebugData( (U08*)debugStr, strlen(debugStr) );
-            sendDebugDataToUI( (U08*)debugStr );
-#endif
-        }
+        }
+        // Bus off - our transmitter has counted 255+ errors
         else if ( notification & canLEVEL_BUS_OFF )
         {
             can1BusOffCnt++;
             if ( TRUE == incTimeWindowedCount( TIME_WINDOWED_COUNT_CAN_OFF ) )
             {
                 SET_ALARM_WITH_1_U32_DATA( ALARM_ID_HD_SOFTWARE_FAULT, SW_FAULT_ID_CAN_OFF_ERROR )
             }
-#ifdef DEBUG_ENABLED
-            sprintf( debugStr, "CAN bus off error:%5d \n", can1BusOffCnt );
-            sendDebugData( (U08*)debugStr, strlen(debugStr) );
-            sendDebugDataToUI( (U08*)debugStr );
-#endif
-        }
+        }
+        // Warning - our transmitter has counted 96+ errors
         else if ( notification & canLEVEL_WARNING )
         {
             can1WarningCnt++;
-#ifdef DEBUG_ENABLED
-            sprintf( debugStr, "CAN bus warning:%5d \n", can1WarningCnt );
-            sendDebugData( (U08*)debugStr, strlen(debugStr) );
-            sendDebugDataToUI( (U08*)debugStr );
-#endif
         }
-        else if ( notification & canLEVEL_PASSIVE )
-        {
-            can1PassiveCnt++;
-            if ( TRUE == incTimeWindowedCount( TIME_WINDOWED_COUNT_CAN_PASSIVE ) )
-            {
-                SET_ALARM_WITH_1_U32_DATA( ALARM_ID_HD_SOFTWARE_FAULT, SW_FAULT_ID_CAN_PASSIVE_WARNING )
-            }
-#ifdef DEBUG_ENABLED
-            sprintf( debugStr, "CAN passive warning:%5d \n", can1PassiveCnt );
-            sendDebugData( (U08*)debugStr, strlen(debugStr) );
-            sendDebugDataToUI( (U08*)debugStr );
-#endif
-        }
         else
         {
-            // Ignore - other notifications undefined
+            // Ignore - other notifications - unhandled
         }
     }
 }
Index: firmware/App/Services/SystemComm.c
===================================================================
diff -u -r1240b612f790f931825aba86ec37f37eccce9336 -r421ffbd3887d136b66da26ee3eeb17dcd9a773b8
--- firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision 1240b612f790f931825aba86ec37f37eccce9336)
+++ firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision 421ffbd3887d136b66da26ee3eeb17dcd9a773b8)
@@ -327,14 +327,6 @@
                     {
                         canTransmit( canREG1, lastCANPacketSentChannel, lastCANPacketSent );
                     }
-#ifdef DEBUG_ENABLED
-                    {
-                        char debugStr[100];
-                        sprintf( debugStr, "SystemComm-HD resend Last Frame. %2d\n", lastCANPacketSentChannel );
-                        sendDebugData( (U08*)debugStr, strlen(debugStr) );
-                        sendDebugDataToUI( (U08*)debugStr );
-                    }
-#endif
                 }
                 // We must be only node on CAN bus - nobody is ACKing our transmitted frames
                 else
@@ -343,13 +335,6 @@
                     canXmitRetryCtr = MAX_XMIT_RETRIES;
                     signalCANXmitsCompleted();          // Clear pending xmit flag
                     clearCANXmitBuffers();              // Clear xmit buffers - nothing is going out right now
-#ifdef DEBUG_ENABLED
-                    {
-                        char debugStr[100];
-                        sprintf( debugStr, "SystemComm-HD is only node.\n" );
-                        sendDebugData( (U08*)debugStr, strlen(debugStr) );
-                    }
-#endif
                 }
             }
         }
@@ -968,13 +953,6 @@
         SET_ALARM_WITH_1_U32_DATA( ALARM_ID_COMM_TOO_MANY_BAD_CRCS, (U32)ALARM_SOURCE_HD );
 #endif
     }
-#ifdef DEBUG_ENABLED
-    {
-        char debugStr[100];
-        sprintf( debugStr, "SystemComm-HD-Bad Msg CRC.\n" );
-        sendDebugDataToUI( (U08*)debugStr );
-    }
-#endif
 }
 
 /*********************************************************************//**
Index: firmware/source/can.c
===================================================================
diff -u -r2112e3143003eaf9584d4be068f7ca89b33c941a -r421ffbd3887d136b66da26ee3eeb17dcd9a773b8
--- firmware/source/can.c	(.../can.c)	(revision 2112e3143003eaf9584d4be068f7ca89b33c941a)
+++ firmware/source/can.c	(.../can.c)	(revision 421ffbd3887d136b66da26ee3eeb17dcd9a773b8)
@@ -517,8 +517,10 @@
     */
 
 /* USER CODE BEGIN (5) */
-    // Enable EIE (error interrupts)
+    // Enable EIE (error interrupts)  // Enable error interrupts for bus transmission issues.
     canREG1->CTL |= (uint32)0x00000008U;
+//    // Enable SIE (error interrupts)  // Enable status interrupts for errors on received frames.  Not Needed except for some engineering testing.
+//    canREG1->CTL |= (uint32)0x00000004U;
 /* USER CODE END */
 }