ABS ESP Module Fault

The symptoms do sound like a problem with the lateral acceleration sensor, or the control unit that uses its data. The sensor is important for systems like ESC and traction control. If it fails, it can trigger the ABS warning and disable safety features. When you said 'affected control unit defective,' did you mean the ABS/ESP module? Have you checked the wiring to the sensor and control unit for corrosion or damage? A loose connection can act like a sensor failure. Also, did you scan for specific fault codes beyond just 'lateral acceleration sensor fault'? Knowing the code can help figure out if it's the sensor, wiring, or the control unit.

Thanks, that's helpful. Yes, 'affected control unit defective' is the ABS/ESP module. I looked at the wiring, but I should check it better for continuity. The scanner gave error code C1234, for a problem in the lateral acceleration sensor circuit. Does that mean the control unit is likely bad, or should I do more tests first?

Error code C1234 does point to a problem in the lateral acceleration sensor circuit. Since you checked the wiring, the code makes it more likely the control unit is bad. You could use an oscilloscope to check the sensor's signal, or a multimeter to check each wire's resistance, but that needs special tools and skills. I think a faulty ABS/ESP module is likely, given the code and symptoms. Before replacing it, check the sensor's power and ground with a multimeter to be sure it's getting the right voltage and has a good ground. If those are okay, I'd suggest getting a professional diagnosis. They can test it more thoroughly and confirm if the module is the problem before you spend money on a replacement.

Thanks for the advice; it was really helpful. I went to a workshop, and they said the ABS/ESP control module needs to be replaced because of an internal fault, like you thought. The repair was about 1000€.