PLC Communication Problems

Hi,

I have a KL connector (pre-wired connector), a USB to serial adapter, and VAGCOM 3.112. I can communicate with the engine control unit (ECU), but I cannot synchronize the baud rate for any other ECUs. It's a Ford Galaxy (new model) from 2000. Do I possibly need a connector with a double K-line (KKL)?

Best regards, Sirecki.

Hello,

No, your car does not use a double K-line.
First, I would check whether it's even possible to access the other control units using VAG-COM, because there's a chance that Ford uses different or software-modified control units here.
Otherwise, I would first get a decent USB diagnostic adapter. With your current additional conversion from USB to RS232 and back, timing problems in the diagnostic protocol are almost guaranteed.

Best regards, Rainer.

Hi,

I tried it today without the adapter, and indeed I was able to communicate with all the available ECUs. It was a bit misleading that the connection to the engine ECU worked, but not to the others.
Thank you for the tip, Rainer.

Best regards, Sirecki.

For your information,
It is the following plug that was purchased from e***:

* Description: INLINE® USB to Serial Adapter Cable, 9-pin.
* Compatible with USB standard V1.1.
* Easiest installation.
* Data transfer rate exceeding 500 kbit/s.
* does not require an interrupt.
USB Type A connector to 9-pin Sub D connector.
* Length approximately 0.2 meters.
* Drivers for Windows 98/ME/2000/XP and Mac OS (8.6, 9.0).
You can adjust quite a few settings when it comes to communication, so I don't want to say for sure that it's definitely the cable, but I just couldn't get it working.

Best regards, Sirecki.

Why don't you try using the search function? There's a lot of information about it there.

While I'm not entirely sure what your technical data is trying to tell me right now, I suspect it might be because your USB-to-RS232 adapter isn't compatible with some of the baud rates being used, or that the signal propagation times are increased by the adapter, which prevents VAG-COM from working correctly. However, the threads you find when using the search function explain possible phenomena and their effects in more detail.