Possible causes, elimination, notes
If "Control module faulty" is displayed in combination with DTC 4226, 4231, 4236, 4241, 4246, 4251, 4256, or 4261, Test point 10 is relevant.
If the control module is damaged, the complete hydraulic unit with integrated control module must be replaced.
Important: Before replacing the hydraulic unit, check whether:
- there are voltage differences due to contact resistance (missing or poor ground connections).
Important: Poor ground connections can be present not only on the affected parts, but also at other important ground points.
- ground is connected to control module connector PIN 16 (from ground point 2) and PIN 19 (from electronics ground). The locations of the ground points are shown on the wiring diagram Ground points.
- positive voltage (vehicle voltage) is connected to control module connector PIN 17 and PIN 18.