B0940
Coolant Level Sensor Circuit Open
B0940 is an OBD-II diagnostic trouble code meaning: Coolant Level Sensor Circuit Open. Common causes: broken or damaged sensor wiring harness, oxidation of sensor contacts. Estimated repair cost: $22–56.
Symptoms
- Coolant level warning light comes on
- Incorrect coolant level readings on the dashboard
- Possible engine overheating
Causes
- Broken or damaged sensor wiring harness
- Oxidation of sensor contacts
- Coolant level sensor malfunction
- Problems with the on-board computer
How to Fix
- Check the coolant level in the expansion tank
- Inspect the wiring harness and sensor contacts for damage and oxidation.
- Check the resistance of the coolant level sensor (compare with factory values)
- If necessary, replace the sensor or repair the wiring harness
- Reset the error and check if it returns
Related codes
Error B0940 by Vehicle Brand
FAQ
What does the B0940 code mean?
B0940 is an OBD-II diagnostic trouble code that indicates: Coolant Level Sensor Circuit Open
What causes a B0940 error code?
The most common causes of B0940 include: Broken or damaged sensor wiring harness; Oxidation of sensor contacts; Coolant level sensor malfunction; Problems with the on-board computer.
How do I fix a B0940 diagnostic trouble code?
To fix B0940: Check the coolant level in the expansion tank. Inspect the wiring harness and sensor contacts for damage and oxidation.. Check the resistance of the coolant level sensor (compare with factory values). For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with B0940?
Limited driving only, diagnose soon
How much does it cost to fix B0940?
The estimated repair cost for B0940 is $22–56. Actual cost depends on your vehicle, location, and labor rates.
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