Serial Port Communication using Bluetooth not Receiving Response, VC++, MFC - mfc

Question

I am developing a ELM327 Simulator device(http://en.wikipedia.org/wiki/ELM327) using VC++ in MFC..It implements Serial port communication with my PC and tab..My Pc contains BLuetooth plugged into it and the device (tab) is being paired with my PC..My program should send the required result for the received response..
Eg:
For Speed, Command : 010D should respond with output 41 0D 12
My problrm is that it is not receiving response from PC after sending command..What could probably the reason be..
Thanks to All
My code For ReceiveData is Like This.
LRESULT CELM327SimDlg::OnReceiveData(WPARAM wParam, LPARAM lParam)
{
int iLen = (int)wParam; // iLen has value 5
LPBYTE lpDataBuffer = (LPBYTE)lParam;
//lpDataBuffer has value AT Z
// Parse and handle the received here.
WORD wCmd = m_ELM327Cmd.ParseAndGetCmd(lpDataBuffer, iLen); //Goes to ParseAndGetCmd function
if( ELM327_CMD_SUP_CMD == wCmd ) //If condition fails program control goes to else part
{
for( int i = 0; i < 3; i++ )
{
m_objSerialPort.SendData(m_ELM327Cmd.GetSupBuf(i), m_ELM327Cmd.GetSupBufLen());
}
}
else
{
DWORD dwData = 0;
switch(wCmd) // Not getting to switch block
{
case ELM327_CMD_RPM:
dwData = m_ctrlRPMSlider.GetPos();
break;
case ELM327_CMD_SPEED:
dwData = m_ctrlSpeedSlider.GetPos();
break;
case ELM327_CMD_MAF:
dwData = m_ctrlMAFSlider.GetPos();
break;
case ELM327_CMD_FUELLVL:
dwData = m_ctrlFuelSlider.GetPos();break;
default:break;
}
if(m_ELM327Cmd.SetResponse(wCmd, dwData)) //Program calling SetResponse function.
{
m_objSerialPort.SendData(m_ELM327Cmd.GetResponseBuf(), m_ELM327Cmd.GetResponseLen());
}
}
if( NULL != lpDataBuffer )
{
delete [] lpDataBuffer;
lpDataBuffer = NULL;
}
return 0;
}
SendData Function is as follows
// Send data to comport
void CSerialPort::SendData(LPBYTE lpBuffer, DWORD dwBytes)
{
if(m_bConnected)
{
if( NULL == lpBuffer || dwBytes == 0 )
{
return;
}
LPBYTE lpDataBuffer = new BYTE[dwBytes];
if( NULL == lpDataBuffer )
{
return;
}
CopyMemory(lpDataBuffer, lpBuffer, dwBytes );
::PostMessage( m_hWnd, UWM_SEND_DATA, (WPARAM)dwBytes, (LPARAM)lpDataBuffer );
}
return;
}