Index: firmware/App/Services/SystemComm.c
===================================================================
diff -u -redd2e65f2ee38fbfdb3d5d3dd06412758ffb1f3a -r8c56613f3786e5605c61824fd75af59702dae648
--- firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision edd2e65f2ee38fbfdb3d5d3dd06412758ffb1f3a)
+++ firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision 8c56613f3786e5605c61824fd75af59702dae648)
@@ -60,7 +60,8 @@
 #define MAX_FPGA_CLOCK_SPEED_ERRORS     3       ///< maximum number of FPGA clock speed errors within window period before alarm
 #define MAX_FPGA_CLOCK_SPEED_ERROR_WINDOW_MS    (10 * SEC_PER_MIN * MS_PER_SECOND)    ///< FPGA clock speed error window
 
-#define PENDING_ACK_LIST_OVERRIDE_UI_CHANNEL    1                                     ///< Value for determining UI or DG channel when Pending ACKs are overriden.
+#define PENDING_ACK_LIST_OVERRIDE_UI_CHANNEL    1                                     ///< Value for determining UI channel when Pending ACKs are overriden.
+#define PENDING_ACK_LIST_OVERRIDE_DG_CHANNEL    2                                     ///< Value for determining DG channel when Pending ACKs are overriden.
 
 #pragma pack(push, 1)
 
@@ -878,15 +879,24 @@
 static BOOL matchACKtoPendingACKList( S16 seqNo )
 {
     BOOL result = FALSE;
-    U32  i;
+    U32  i;
 
     // Find match
     for ( i = 0; i < PENDING_ACK_LIST_SIZE; i++ )
     {
         if ( ( TRUE == pendingAckList[ i ].used ) && ( pendingAckList[ i ].seqNo == seqNo ) )
-        {   // Remove message pending ACK from list
-            pendingAckList[ i ].used = FALSE;
-            result = TRUE;
+        {
+            if ( ( ( getU32OverrideValue( &pendingACKOverride ) == PENDING_ACK_LIST_OVERRIDE_UI_CHANNEL ) && ( pendingAckList[ i ].channel == COMM_BUFFER_OUT_CAN_HD_2_UI ) ) ||
+                 ( ( getU32OverrideValue( &pendingACKOverride ) == PENDING_ACK_LIST_OVERRIDE_DG_CHANNEL ) && ( pendingAckList[ i ].channel == COMM_BUFFER_OUT_CAN_HD_2_DG ) ) )
+            {
+                pendingAckList[ i ].used = TRUE;
+                result = FALSE;
+            }
+            else // Remove message pending ACK from list
+            {
+                pendingAckList[ i ].used = FALSE;
+                result = TRUE;
+            }
             break;
         }
     }
@@ -910,7 +920,7 @@
     // Find expired messages pending ACK
     for ( i = 0; i < PENDING_ACK_LIST_SIZE; i++ )
     {   // Pending ACK expired?
-        if ( ( TRUE == pendingAckList[ i ].used ) && ( ( TRUE == didTimeout( pendingAckList[ i ].timeStamp, MSG_NOT_ACKED_TIMEOUT_MS ) ) ||  ( getU32OverrideValue( &pendingACKOverride ) > 0 ) ) )
+        if ( ( TRUE == pendingAckList[ i ].used ) && ( ( TRUE == didTimeout( pendingAckList[ i ].timeStamp, MSG_NOT_ACKED_TIMEOUT_MS ) ) ) )
         {   // If retries left, reset and resend pending message
             if ( pendingAckList[ i ].retries > 0 )
             {   // Re-queue message for transmit
@@ -925,8 +935,7 @@
 
                 memcpy( &msgID, (U08*)&pendingAckList[ i ].msg[ sizeof( U08 ) + sizeof( U16) ], sizeof( U16 ) );
 
-                if ( ( pendingAckList[ i ].channel != COMM_BUFFER_OUT_CAN_HD_2_DG ) ||
-                     ( getU32OverrideValue( &pendingACKOverride ) == PENDING_ACK_LIST_OVERRIDE_UI_CHANNEL ) )
+                if ( pendingAckList[ i ].channel != COMM_BUFFER_OUT_CAN_HD_2_DG )
                 {
                     SET_ALARM_WITH_1_U32_DATA( ALARM_ID_HD_CAN_MESSAGE_NOT_ACKED_BY_UI, (U32)msgID );
                 }