My 1995 E320 has the check engine light on and I'm trying use my knock-off Star scanner to read the codes. This car has the 16 pin port with an LED. I put the black cable into #1 and red into #16 which powers up the multiplexer with it's green light on and the ignition on. Then I put the yellow signal wire into pin 3 and run the test. Then is says Fault in PC diagnostic multiplexer link. Voltage supply cable. So what am I doing wrong? There is also a white cable but where do I put that?