B3420
Automatic Headlamp Leveling Control Module Rear Axle Sensor Signal
B3420 is an OBD-II diagnostic trouble code meaning: Automatic Headlamp Leveling Control Module Rear Axle Sensor Signal. Common causes: malfunction of the level sensor on the rear axle, open or shorted wiring harness. Estimated repair cost: $56–167.
Symptoms
- Incorrect headlight angle
- Error message on the dashboard
- Flashing headlights
Causes
- Malfunction of the level sensor on the rear axle
- Open or shorted wiring harness
- Problems with the headlight level control module
- Contact corrosion
How to Fix
- Check the level sensor on the rear axle for damage
- Check the integrity of the wiring harness and contacts
- Scan the control module for errors
- Replace sensor or wiring harness if necessary
Related codes
Error B3420 by Vehicle Brand
FAQ
What does the B3420 code mean?
B3420 is an OBD-II diagnostic trouble code that indicates: Automatic Headlamp Leveling Control Module Rear Axle Sensor Signal
What causes a B3420 error code?
The most common causes of B3420 include: Malfunction of the level sensor on the rear axle; Open or shorted wiring harness; Problems with the headlight level control module; Contact corrosion.
How do I fix a B3420 diagnostic trouble code?
To fix B3420: Check the level sensor on the rear axle for damage. Check the integrity of the wiring harness and contacts. Scan the control module for errors. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with B3420?
Limited driving only, diagnose soon
How much does it cost to fix B3420?
The estimated repair cost for B3420 is $56–167. Actual cost depends on your vehicle, location, and labor rates.
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