diff --git a/Train.cpp b/Train.cpp
index 98c7f185..e7a9b3b4 100644
--- a/Train.cpp
+++ b/Train.cpp
@@ -7420,6 +7420,11 @@ bool TTrain::Update( double const Deltatime )
 		btCabActived.Turn(false);
     }
 
+    if (mvControlled->Battery && mvControlled->CabActive == 0)
+		btAKLVents.Turn(true);
+	else
+		btAKLVents.Turn(true);
+
     if( true == lowvoltagepower ) {
         // McZapkie-141102: SHP i czuwak, TODO: sygnalizacja kabinowa
         if( mvOccupied->SecuritySystem.is_vigilance_blinking() ) {
@@ -10123,6 +10128,7 @@ bool TTrain::initialize_button(cParser &Parser, std::string const &Label, int co
         { "i-universal8:", btUniversals[ 8 ] },
         { "i-universal9:", btUniversals[ 9 ] },
         { "i-cabactived:", btCabActived },
+	    {"i-aklvents:", btAKLVents},
 	    {"i-compressorany:", btCompressors }
     };
     {
diff --git a/Train.h b/Train.h
index 5346e648..69eb99f2 100644
--- a/Train.h
+++ b/Train.h
@@ -773,6 +773,7 @@ public: // reszta może by?publiczna
     TButton btLampkaRearLeftEndLight;
     TButton btLampkaRearRightEndLight;
 	TButton btCabActived;
+	TButton btAKLVents;
 	TButton btCompressors;  // lampka pracy jakiejkolwiek sprezarki
     // other
     TButton btLampkaMalfunction;