diff --git a/java_console/io/src/main/java/com/rusefi/io/can/Elm327Connector.java b/java_console/io/src/main/java/com/rusefi/io/can/Elm327Connector.java
index 8967077ac1..4e82dbdd5d 100644
--- a/java_console/io/src/main/java/com/rusefi/io/can/Elm327Connector.java
+++ b/java_console/io/src/main/java/com/rusefi/io/can/Elm327Connector.java
@@ -63,10 +63,11 @@ public class Elm327Connector implements Closeable {
 		return tsStream;
 	}
 
-	public void start(String msg) {
+	public boolean start(String msg) {
     	log.info("* Elm327.start()");
 
-        if (initConnection(msg)) {
+		boolean initConnection = initConnection(msg);
+		if (initConnection) {
         	// reset to defaults
         	sendCommand("ATD", "OK");
 
@@ -109,7 +110,7 @@ public class Elm327Connector implements Closeable {
 			String voltage = sendCommand("ATRV", "([0-9\\.]+)V");
 			log.info("* Ignition voltage = " + voltage);
         }
-
+        return initConnection;
     }
 
     @Override
diff --git a/java_console/io/src/main/java/com/rusefi/io/can/IsoTpCanDecoder.java b/java_console/io/src/main/java/com/rusefi/io/can/IsoTpCanDecoder.java
index 48916343a0..e87cc53fb5 100644
--- a/java_console/io/src/main/java/com/rusefi/io/can/IsoTpCanDecoder.java
+++ b/java_console/io/src/main/java/com/rusefi/io/can/IsoTpCanDecoder.java
@@ -69,7 +69,7 @@ public class IsoTpCanDecoder {
         }
         byte[] bytes = Arrays.copyOfRange(data, dataOffset, dataOffset + numBytesAvailable);
         if (log.debugEnabled())
-            log.debug(numBytesAvailable + " bytes(s) arrived in this packet: " + IoStream.printHexBinary(bytes));
+            log.debug(numBytesAvailable + " bytes(s) arrived in this packet: " + IoStream.printByteArray(bytes));
         return bytes;
     }
 }
diff --git a/java_console/io/src/test/java/com/rusefi/binaryprotocol/test/Elm327Sandbox.java b/java_console/io/src/test/java/com/rusefi/binaryprotocol/test/Elm327Sandbox.java
index 91b8eaa0b2..50acab54d9 100644
--- a/java_console/io/src/test/java/com/rusefi/binaryprotocol/test/Elm327Sandbox.java
+++ b/java_console/io/src/test/java/com/rusefi/binaryprotocol/test/Elm327Sandbox.java
@@ -21,7 +21,9 @@ public class Elm327Sandbox {
         BaudRateHolder.INSTANCE.baudRate = ELM327_DEFAULT_BAUDRATE;
         String serialPort = "COM7";
         Elm327Connector connector = new Elm327Connector(SerialIoStream.openPort(serialPort));
-        connector.start(serialPort);
+        boolean initConnection = connector.start(serialPort);
+        if (!initConnection)
+            return;
 
         IoStream tsStream = connector.getTsStream();
 
@@ -68,7 +70,7 @@ public class Elm327Sandbox {
             byte[] fResponse = new byte[3];
             dataBuffer.waitForBytes("CRC", System.currentTimeMillis(), fResponse.length);
             dataBuffer.getData(fResponse);
-            System.out.println(" Got CRC response " + IoStream.printHexBinary(fResponse));
+            System.out.println(" Got CRC response " + IoStream.printByteArray(fResponse));
         }
 
         LinkManager linkManager = new LinkManager();
@@ -94,7 +96,7 @@ public class Elm327Sandbox {
         byte[] fResponse = new byte[3];
         dataBuffer.waitForBytes("hello", System.currentTimeMillis(), fResponse.length);
         dataBuffer.getData(fResponse);
-        System.out.println(prefix + " Got F response " + IoStream.printHexBinary(fResponse));
+        System.out.println(prefix + " Got F response " + IoStream.printByteArray(fResponse));
     }
 
 }