B0121
Fluid Reservoir Level Sensor F
B0121 is an OBD-II diagnostic trouble code meaning: Fluid Reservoir Level Sensor F. Common causes: liquid level sensor malfunction, open or short circuit in wiring harness. Estimated repair cost: $56–167.
Symptoms
- The passive safety system fault indicator is on
- The passive safety system can be disabled
- Incorrect liquid level readings
Causes
- Liquid level sensor malfunction
- Open or short circuit in wiring harness
- Poor contact in the sensor connector
- Damage to the fluid reservoir
How to Fix
- Check the fluid level in the reservoir
- Inspect the sensor and its connector for damage
- Check the integrity of the sensor circuit
- Replace sensor if necessary
- Clean or replace connector if there is corrosion
Related codes
Error B0121 by Vehicle Brand
FAQ
What does the B0121 code mean?
B0121 is an OBD-II diagnostic trouble code that indicates: Fluid Reservoir Level Sensor F
What causes a B0121 error code?
The most common causes of B0121 include: Liquid level sensor malfunction; Open or short circuit in wiring harness; Poor contact in the sensor connector; Damage to the fluid reservoir.
How do I fix a B0121 diagnostic trouble code?
To fix B0121: Check the fluid level in the reservoir. Inspect the sensor and its connector for damage. Check the integrity of the sensor circuit. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with B0121?
Do not drive — repair immediately
How much does it cost to fix B0121?
The estimated repair cost for B0121 is $56–167. Actual cost depends on your vehicle, location, and labor rates.
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