Volkswagen up! ABS Fault

No Fault Found: £70+VAT checking fee retained; remaining repair cost refunded.
Beyond Repair: Full repair refund if deemed beyond economical repair.

This ABS pump and module are installed in the Volkswagen up! series of compact family vehicles, as well as in the Seat Mii and Skoda Citigo (which are rebranded versions of the up!).

If you encounter a common ABS function failure, you would typically use diagnostic tools to scan the vehicle or take it to a garage. In such cases, fault codes are often found stored in the ABS, with the most prevalent one being C107701 – ABS Hydraulic/Return Flow Pump. We receive a considerable number of these ABS pump and module units for testing, specifically for faults related to C107701. Symptoms of this fault include the absence of emergency ABS braking assistance and the constant illumination of the ABS and traction control warning lights.

Wheel speed sensor fault codes, primarily C101B01 – Wheel Speed Sensor Front Right Electrical Fault and C101A14 – Wheel Speed Sensor Front Left Electrical Fault

These fault codes trigger continuous ABS and traction control warning lights, hindering effective ABS assistance. Importantly, these codes are often caused by factors external to the ABS pump and module.

Solution

C107701 – ABS Hydraulic/Return Flow Pump

This fault is typically not caused by the ABS unit itself; more often, it results from a supply voltage error. Check the ABS pump fuse, a high-amperage fuse for the ABS located in the engine bay fuse box. The resistance of the ABS fuse should read 0 ohms; if it measures open circuit, replace the fuse and retest the ABS. Examine and replace the 40-amp fuse (F5) as needed, and conduct wiring checks to ensure there are no voltage drops.

Wheel speed sensor fault codes: predominately C101B01 – Wheel Speed Sensor Front Right Electrical Fault & C101A14 – Wheel Speed Sensor Front Left Electrical Fault

These codes often stem from wiring defects to/from the wheel speed sensor or the sensor itself. When reviewing live data, anticipate observing a defective or missing signal from the affected sensor.