def decode_0x03(data):
    """
    Decode the bit-encoding of Mode 01, PID 03 and return appropriate string.

    This is apparently bit-encoded, but only one bit may be set at any one time.
    If you want the raw value, just do int([0:1]) on the string.
    """
    if data == 1:
        return '01: Open loop due to insufficient engine temperature'
    elif data == 2:
        return '02: Closed loop, using oxygen sensor feedback to determine fuel mix'
    elif data == 4:
        return '04: Open loop due to engine load OR fuel cut due to deceleration'
    elif data == 8:
        return '08: Open loop due to system failure'
    elif data == 16:
        return '16: Closed loop, using at least one oxygen sensor but there is a fault in the feedback system'
    else:
        return 'NO DATA'