No se puede enviar el comando ATZ al ELM 327 después de establecer la conexión con ELM327 en Android

He escrito un código que puede encontrar con éxito el OBD emparejado y establecer la conexión con ELM327, pero cuando intento enviar el comando ATZ, la aplicación se bloquea.

Aquí está el fragmento de código, puede que haya hecho mal

public HashMap<String, String> startOBDCommunicator(
            BluetoothSocket btSocketConnected, String paramClassName,
            String methodName) {

        HashMap<String, String> dataRetriever = new HashMap<String, String>();
        sendDataToOBD(btSocketConnected, "ATZ\r");
        dataRetriever.put("Reset", readDataFromOBD(btSocketConnected));

        sendDataToOBD(btSocketConnected, "ATS0\r");
        dataRetriever.put("Space Control", readDataFromOBD(btSocketConnected));

        sendDataToOBD(btSocketConnected, "ATE0\r");
        dataRetriever.put("Echo control", readDataFromOBD(btSocketConnected));

        sendDataToOBD(btSocketConnected, "ATL0\r");
        dataRetriever.put("Line feed", readDataFromOBD(btSocketConnected));

        sendDataToOBD(btSocketConnected, "ATAT0\r");
        dataRetriever
                .put("Adaptive Timing", readDataFromOBD(btSocketConnected));

        sendDataToOBD(btSocketConnected, "ATST10\r");
        dataRetriever.put("Time Out", readDataFromOBD(btSocketConnected));

        sendDataToOBD(btSocketConnected, "ATI\r");
        dataRetriever.put("Device Description",
                readDataFromOBD(btSocketConnected));

        sendDataToOBD(btSocketConnected, "ATDP\r");
        dataRetriever.put("Protocol Information1",
                readDataFromOBD(btSocketConnected));

        sendDataToOBD(btSocketConnected, "ATSPA0\r");
        dataRetriever
                .put("Auto Protocol",
                        readBytesFromOBD(btSocketConnected, paramClassName,
                                methodName));

        sendDataToOBD(btSocketConnected, "010C\r");

        dataRetriever
                .put("RPM param",
                        readBytesFromOBD(btSocketConnected, paramClassName,
                                methodName));

        sendDataToOBD(btSocketConnected, "010D\r");

        dataRetriever
                .put("Speed parameters",
                        readBytesFromOBD(btSocketConnected, paramClassName,
                                methodName));

        sendDataToOBD(btSocketConnected, "0104\r");

        dataRetriever
                .put("engine load value parameters",
                        readBytesFromOBD(btSocketConnected, paramClassName,
                                methodName));

        sendDataToOBD(btSocketConnected, "0105\r");

        dataRetriever
                .put("Engine coolant temperature parameters",
                        readBytesFromOBD(btSocketConnected, paramClassName,
                                methodName));

        sendDataToOBD(btSocketConnected, "012F\r");

        dataRetriever
                .put("Fuel Level Input",
                        readBytesFromOBD(btSocketConnected, paramClassName,
                                methodName));

        return dataRetriever;

    }

No estoy seguro de dónde he cometido errores, así que estoy compartiendo el flujo de todo el código como dos gist,https://gist.github.com/sankarganesh/6376031, esta esencia contiene el archivo de actividad y una información más para Bluetooth Socket Listenerhttps://gist.github.com/sankarganesh/6376039