OBD Guide

B3123

Keyless Entry Antenna 5

B3123 is an OBD-II diagnostic trouble code meaning: Keyless Entry Antenna 5. Common causes: broken or damaged antenna wiring harness, malfunction of the antenna itself. Estimated repair cost: $167–333.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$167–333 (est.)

Symptoms

  • Problems with keyless entry
  • The system does not recognize the key in certain areas of the cabin
  • Error indication on the dashboard

Causes

  • Broken or damaged antenna wiring harness
  • Malfunction of the antenna itself
  • Problems with the keyless entry module

How to Fix

  1. Checking the antenna wiring harness for breaks and damage
  2. Checking Antenna Resistance
  3. Replacing antenna 5 if necessary
  4. Checking and updating the keyless entry module software

Related codes

Error B3123 by Vehicle Brand

FAQ

What does the B3123 code mean?

B3123 is an OBD-II diagnostic trouble code that indicates: Keyless Entry Antenna 5

What causes a B3123 error code?

The most common causes of B3123 include: Broken or damaged antenna wiring harness; Malfunction of the antenna itself; Problems with the keyless entry module.

How do I fix a B3123 diagnostic trouble code?

To fix B3123: Checking the antenna wiring harness for breaks and damage. Checking Antenna Resistance. Replacing antenna 5 if necessary. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B3123?

Yes, but get it checked soon

How much does it cost to fix B3123?

The estimated repair cost for B3123 is $167–333. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat