I have a problem with steering assist - it is too heavy in every conditions. I have no active DTCs, but there are some in the memory:

U0415-00 Invalid data received from ABS control module (Status: Intermittent)
B12FA-13 Servotronic valve circuit open circuit (Status: Untested)
B12FB-12 Servotronic valve circuit short circuit to power (Status: Untested)

I assume that last two of them were caused by my test - I connected 12V directly to servotronic valve. This results with light steering so the problem is signal from control module to the valve. Wiring up to junction box is ok.
My questions:
1. If any DTC (like this with ABS) causes disturbance of the control of servotronic valve - how to bring it back to action? I think the problem might be short lack of speed signal from ABS. But why steering assist is not restored when signal is ok?
2. Which module controls the valve - is there any method of diagnosis why it is not working correctly?

Thanks for any help or suggestions.

 

hi, I have the same dtcs, my steering is stiff, did you manage to solve your problem?

 

Unfortunately not.