What it means
The ABS module monitors the right rear inlet valve, which controls hydraulic pressure applied to that wheel. It sets this code when the valve circuit or operation does not respond as expected.
At a glance
- Usually lights the ABS or stability-control warning light
- The engine or gearbox may go into limp mode
How it works
The right rear inlet valve in the ABS hydraulic unit controls pressure applied to that wheel during ABS or stability-control operation. C001C is stored when the ABS module detects that the right rear inlet-valve circuit or operation does not respond as expected.
Common causes
Most likely first.
- Inlet valve coil failure
- Valve stuck or contaminated
- Damaged wiring or connector
- ABS module fault
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
How to diagnose it
- Read ABS-module codes and freeze-frame data to identify the conditions when the right rear inlet-control fault occurred and any related faults.
- Inspect the right rear inlet-valve connector and harness for corrosion, loose pins, chafing, or damaged insulation.
- Check ABS power and grounds before condemning the valve, since supply problems can disrupt its control.
- Test the right rear inlet-valve circuit for continuity and shorts using the manufacturer’s diagnostic procedure.
- If the circuit is sound, test the valve coil and commanded operation to determine whether the coil has failed or the valve is sticking.
- Investigate the ABS module only if the right rear valve and its circuit pass their checks.
Common fixes
- Clean and secure the right rear inlet-valve connector or repair its damaged wiring.
- Correct a faulty ABS power or ground connection.
- Replace the failed right rear inlet-valve coil or valve when confirmed by testing.
- Repair or replace the ABS hydraulic unit if the right rear inlet valve is stuck internally.
- Repair the ABS module if its control output is faulty after other causes are excluded.
Can I keep driving?
ABS or stability control may be disabled, reducing control during hard braking or on slippery roads. Drive cautiously and get the brake system checked promptly; stop if the pedal or braking response changes.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.