B0521
Tachometer Signal Circuit Malfunction
B0521 is an OBD-II diagnostic trouble code meaning: Tachometer Signal Circuit Malfunction. Common causes: broken or damaged tachometer circuit wires, tachometer malfunction. Estimated repair cost: $56–167.
Symptoms
- Tachometer does not work
- Floating idle speed
- The engine may stall
Causes
- Broken or damaged tachometer circuit wires
- Tachometer malfunction
- Problems with the crankshaft speed sensor
- Corrosion or poor contact in connectors
- ECU malfunction
How to Fix
- Check the integrity of the tachometer circuit wiring
- Check contacts in connectors
- Check crankshaft speed sensor
- Check the serviceability of the tachometer
- If necessary, replace faulty components
Related codes
Error B0521 by Vehicle Brand
FAQ
What does the B0521 code mean?
B0521 is an OBD-II diagnostic trouble code that indicates: Tachometer Signal Circuit Malfunction
What causes a B0521 error code?
The most common causes of B0521 include: Broken or damaged tachometer circuit wires; Tachometer malfunction; Problems with the crankshaft speed sensor; Corrosion or poor contact in connectors.
How do I fix a B0521 diagnostic trouble code?
To fix B0521: Check the integrity of the tachometer circuit wiring. Check contacts in connectors. Check crankshaft speed sensor. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with B0521?
Limited driving only, diagnose soon
How much does it cost to fix B0521?
The estimated repair cost for B0521 is $56–167. Actual cost depends on your vehicle, location, and labor rates.
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