B011E

What it means

B011E is the generic code for a fault in the circuit or signal of Fluid Reservoir Level Sensor C. The control unit that monitors it saw a reading that was implausible, out of range, or an open or short circuit, or it saw a genuinely low fluid level. Which fluid and reservoir 'C' refers to (for example screenwash, coolant, brake or another fluid) depends on the make, model and the module that stores the code.

Symptoms

• Warning light or message about low fluid level on the dashboard
• Level warning that stays on even though the reservoir is full
• Level warning that comes and goes, especially over bumps or on cornering
• Related system warning displayed alongside the code
• No visible symptoms apart from the stored code

Possible causes

• Fluid level genuinely low in the monitored reservoirlikely
• Faulty level sensor or float switch, or one that is contaminated or stickinglikely
• Damaged wiring, corrosion or a loose connector at the sensorlikely
• Leak in the system the reservoir serves, causing repeated low levelpossible
• Poor earth or supply voltage to the sensor circuitpossible
• Fault in the control module that reads the sensorrare

How to diagnose

1. Identify which fluid reservoir sensor C refers to for this exact make, model and year, using the manufacturer's information.
2. Read all stored codes and freeze frame data, noting whether the fault is current or intermittent.
3. Check the fluid level in the reservoir with the car on level ground and top up with the correct specification if it is low.
4. Inspect the sensor, its connector and the wiring for damage, corrosion, water ingress, chafing or fluid contamination.
5. Look around the reservoir and the related system for signs of leaks.
6. Check the sensor's supply, earth and signal circuits with a multimeter against the manufacturer's data.
7. Test the sensor's resistance or switching action as the fluid level changes, following the model-specific procedure.
8. Clear the code and road test to see if it returns, and if so, check the control module's connections and operation.

How to fix

• Top up the reservoir with the correct fluid and repair any leak found.
• Replace the faulty level sensor or float assembly.
• Repair or replace damaged wiring and clean or replace corroded connectors.
• Restore a good earth or supply to the sensor circuit.
• Replace or reprogram the control module only after the wiring and sensor have been proven good and the manufacturer confirms a module fault.

Can I keep driving?

Nearby codes

• B011DGenericFluid Reservoir Level Sensor B
• B011FGenericFluid Reservoir Level Sensor D