title: Bluetooth OBDII / ELM giving duplicate data as response
body: <p>I a HC-05 connected to an Arduino's Serial 3. I have also been able to successfully pair with an OBD2-ELM adapter in the car,</p>
  
  <p>I have a code in my sketch to do simple communications with the OBD/ELM</p>
  
  <pre><code>if (Serial3.available()) {
      Serial.write(Serial3.read());
  }
  if (Serial.available()) {
      Serial3.write(Serial.read());
  }
  </code></pre>
  
  <p>The challenge is this:<br>
  If I type ATZ, I get "ELM327 v2.1>"<br>
  I type ATTP5, I get "OK>"<br>
  Typing ATRV, returns "12.6"<br>
  But if I type 0105 I get different responses such as:<br>
  <strong>"LM327410v2 ELMv241 M2.11099"</strong>, or <strong>"OK>LM7v41A"</strong> or <strong>"OK> OK > 41055.1 327v"</strong>  </p>
  
  <p>Other times I get the correct response of <strong>"4105 5A >"</strong>  </p>
  
  <p>I get the same result when I type in 0100 or any other PID code.</p>
  
  <p>Please does anyone have an idea as to what might be causing this and how to
  fix it.</p>
  
  <p>Thanks</p>