OBD Guide

B3120

Keyless Entry Antenna 2

B3120 is an OBD-II diagnostic trouble code meaning: Keyless Entry Antenna 2. Common causes: antenna damage, open or short circuit in wiring harness. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • The keyless entry system does not respond to the key fob
  • Intermittent operation of the access system
  • The malfunction indicator on the dashboard lights up

Causes

  • Antenna damage
  • Open or short circuit in wiring harness
  • Access control unit malfunction
  • Contact corrosion

How to Fix

  1. Check antenna integrity
  2. Check wiring harness for damage
  3. Check connections and contacts
  4. Replace the antenna if necessary
  5. Test the system after repair

Related codes

Error B3120 by Vehicle Brand

FAQ

What does the B3120 code mean?

B3120 is an OBD-II diagnostic trouble code that indicates: Keyless Entry Antenna 2

What causes a B3120 error code?

The most common causes of B3120 include: Antenna damage; Open or short circuit in wiring harness; Access control unit malfunction; Contact corrosion.

How do I fix a B3120 diagnostic trouble code?

To fix B3120: Check antenna integrity. Check wiring harness for damage. Check connections and contacts. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B3120?

Limited driving only, diagnose soon

How much does it cost to fix B3120?

The estimated repair cost for B3120 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat