Wiring or connector fault between the ABS control unit or hydraulic unit and the vehicle harness (corrosion, damaged pins, chafed wires); Faulty right rear inlet valve or solenoid inside the hydraulic modulator; Low or unstable system voltage from a weak battery, poor charging or bad earth connections; Blown fuse or faulty relay supplying the valve or pump circuit; Internal fault in the ABS control unit driver circuit; Water ingress or contamination in the modulator connector or control unit.

C001C

Right Rear Inlet Control.

Generic
Chassis
Generic code
Medium severity

How this code is built

C: SystemChassis
0: Defined bySAE, the same on every car
0: AreaChassis area 0
1C: FaultThe specific fault in that area

What it means

C001C is defined generically as a Right Rear Inlet Control fault, which relates to the control circuit for the right rear inlet valve in the ABS or stability control hydraulic unit. The ABS control unit sets it when it sees an electrical or functional fault in that valve's circuit, such as an open circuit, short circuit or a valve that does not respond as commanded. The exact valve layout and test values depend on the vehicle and brake system, so check model-specific data.

Symptoms

ABS warning light on
Traction or stability control warning light on
ABS, traction or stability control not working
Possible harsh or uneven ABS operation, or none, on a low-grip surface
Other ABS or stability control codes stored at the same time

Possible causes

Wiring or connector fault between the ABS control unit or hydraulic unit and the vehicle harness (corrosion, damaged pins, chafed wires)likely
Faulty right rear inlet valve or solenoid inside the hydraulic modulatorlikely
Low or unstable system voltage from a weak battery, poor charging or bad earth connectionspossible
Blown fuse or faulty relay supplying the valve or pump circuitpossible
Internal fault in the ABS control unit driver circuitpossible
Water ingress or contamination in the modulator connector or control unitrare

How to diagnose

Read all stored codes and freeze frame data, noting whether other ABS or stability control codes are present and whether the fault is current or historic
Check battery condition and charging voltage, as low voltage can set valve circuit faults
Check the relevant fuses and relays against the vehicle wiring diagram
Visually inspect the wiring and connector at the hydraulic unit and control unit for corrosion, water, bent pins and chafing
Check the brake fluid level and look for leaks around the hydraulic unit
Check the supply and earth feeds to the ABS unit with a multimeter
Measure the valve circuit resistance and wiring continuity to manufacturer specification, where the unit allows access
Run an actuator or valve test if the system supports it, then clear the code and road test to see if it returns

How to fix

Repair or replace damaged wiring and clean or replace corroded or damaged connectors
Correct charging or battery faults and repair poor earth connections
Replace any blown fuse or faulty relay once the cause of the failure has been found
Repair or replace the hydraulic modulator or valve block if the inlet valve is confirmed faulty
Repair or replace the ABS control unit if it is confirmed faulty, with any coding or programming the manufacturer requires

Can I keep driving?

Medium severity

The normal braking system usually still works, but ABS and stability control may be disabled, so allow extra braking distance, especially in wet or icy conditions. Have it checked soon, and stop driving if the brake warning light is on or the pedal feels abnormal.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.