Alhambra CFFB: No Start, No TCU Communication

Hello everyone,

I'm having a strange problem and I'm not sure how to approach it right now...

The Alhambra was manufactured in 2011 and has a 2.0 TDI CFFB engine.
The engine is turning, but it's not firing.
Sometimes it does ignite and starts immediately, but then it turns off after 1 second --> WFS.

The reason I'm applying for a position in the vehicle electrical systems department is as follows:

I cannot select any STG at all.
The diagnostic cable receives power when plugged in (the LED lights up).
I have tested all the fuses and found no defects.

Is there a known vulnerability in this model?

Thank you in advance!

Best regards,
Christian.

Hi,

If no control unit is responding, either one of the corresponding pins for diagnostics in the OBD2 connector has slipped backward, or one or more control units are not receiving power.

I would therefore first check the OBD2 port in the car and then see if any control unit is responding and definitely working. If that doesn't work either, first check if the gateway control unit (control unit address 19) is receiving power.

Best regards, Rainer.

Thank you for the response.

All the pins in the connector are properly seated.
The speedometer is definitely not working and cannot be accessed, for example.

Is the gateway control unit located behind the fuses inside the car? (At least, I see a control unit there, and I quickly found only this location online.)
In the older Sharan model, the Comfort Control Unit (CCU) was located approximately in that area.

As far as I can see, this would require disassembling half the car, and they only want to do that if they are sure it's there.

Hi,

Quote:

Isn't the gateway control unit located behind the fuses inside the car? (at least, I see a control unit there, and I quickly found only this installation location online). In the older Sharan, the comfort control unit (STG) was located approximately there.

I have no idea where it's located in the Sharan/Alhambra, but try addressing it directly via the control unit address 19.

If that's not the issue, then either the electrical connection from the OBD2 port to the gateway is faulty, the gateway is not receiving power (in which case, you'd likely see a Christmas tree of warning lights), or the gateway itself is defective.

You still haven't written what the other control units do that should be active when "ignition is ON." Are they functioning, yes or no? Otherwise, it's obvious that these components are not receiving power.

Best regards, Rainer.

He says he can't select any STG channels.
Is the interface configured correctly?
hg
Herbert.

There aren't many settings you can adjust, and the interface is also used in other cars regularly, so everything should be working correctly.

Unfortunately, I don't have the Alhambra at home with me yet. Once I get it here, I will check the power supply from the gateway.

Quote:

The speedometer is definitely not working and, for example, cannot be accessed.

Thank you very much!

The body control module is installed in the driver's side footwell, below the relay carrier. This applies to vehicles with left-hand drive.

I just checked the VW repair manual, and it seems like the removal process isn't very complicated.

I now have the car, and unfortunately, nothing has changed, not even the 19th [item/issue].

As far as I've read so far, the part number 19 refers to the CAN diagnostic gateway 7N09075630A (located above the accelerator pedal). The body control module 5k0937087H is located above the fuse box.

Or am I getting something mixed up here?


My problem is that I can find the body control module in the wiring diagrams, but not the gateway... Is there a specific term used for it at VW?

Thank you very much!

I can't find the location of the gateway in the documentation I obtained from Erwin.

Check out "diagnostic interface for data bus".
With the wiring diagram from Erwin, you can also find the installation location.
hg
Herbert.

I've at least found the pin assignments.

Pin 1: Constant positive voltage (30).
Pin 2: Constant positive (+) (30) (until May 06).
Pin 3:
Pin 4:
Pin 5: Comfort CAN low.
Pin 6: CAN low drive.
Pin 7:
Pin 8: KI CAN low.
Pin 9: CAN low diagnostic.
Pin 10: Infotainment CAN low.
Pin 11: Ground.
Pin 12: Ground (until May 06).
Pin 13: K-Line.
Pin 14: Ignition power (15a)
Pin 15: Comfort CAN high.
Pin 16: CAN high driver.
Pin 17:
Pin 18: AI CAN high.
Pin 19: CAN high diagnostic.
Pin 20: Infotainment CAN high.

@Herbert, thank you very much for the term. In the other programs from VW, this part is usually called a CAN gateway...

Hi!

Have you ever tried disconnecting the power to the gateway?

Regards,
Brezelmann.

Hello,

Sorry, I completely forgot because of all the holidays.
It was the power supply. The cable with terminal 30 had a break. It's not always easy to figure that out.

Thank you very much for all the information!