The ABS and/or ESP warning light came on in my Citroën C4’s dashboard. Could the system fuse have blown? Which fuse should I check and where is it located?

The Anti-lock Braking System (ABS) and Electronic Stability Control (ESP) are crucial for safety. They share the same module (the hydraulic control unit) and have specific electrical protections. The warning light usually indicates a fault in the wheel sensor (the most common cause), but a blown power fuse could also be the cause.

• Focused Model: Citroën C4 Hatch, Pallas or Lounge (typical models 2004/2012).
• Location of Protection: The fuse is in Engine Service Module (BSM), under the hood, as it is a high-power circuit (ABS pump motor).

Correct Fuses (Important: ABS uses more than one fuse!):

1. ABS/ESP Module Power Supply Fuse (Low Amperage): It is the fuse that powers the control unit of the ABS. For the C4, a fuse of 10A (variable location, it could be the F07 or F06 (in BSM) protects the control circuit.
2. Power Fuses for the Electric Pump (High Amperage): The ABS pump motor, which requires high current, has larger fuses. They are usually identified as Fuse F02 and F03 (or similar, depending on the diagram) with high amperage, typically 30A or 50A, located in a larger fuse area of ​​the BSM.

Diagnosis: If the ABS/ESP lights have come on, check the control fuse. 10A and the power fuses of 30A to 50A. However, troubleshooting an ABS module is complex; if the fuse is blown, it may indicate a short circuit in the ABS hydraulic pump, which will require replacing the module.