OBD Guide

B129A

LIN Bus D Signal Invalid

B129A is an OBD-II diagnostic trouble code meaning: LIN Bus D Signal Invalid. Common causes: open or short circuit in lin d bus wiring, damage to connectors or corrosion of contacts. Estimated repair cost: $56–167.

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

Symptoms

  • Inoperability of some electronic systems
  • Check Engine Light Illuminates
  • Unstable climate control operation

Causes

  • Open or short circuit in LIN D bus wiring
  • Damage to connectors or corrosion of contacts
  • Fault in one of the modules connected to the LIN D bus
  • Problems with power supply or grounding of modules

How to Fix

  1. Check the integrity of the LIN D bus wiring
  2. Inspect connectors and contacts for damage or corrosion
  3. Check power supply and grounding of connected modules
  4. Replace the faulty module if it is the problem

Related codes

FAQ

What does the B129A code mean?

B129A is an OBD-II diagnostic trouble code that indicates: LIN Bus D Signal Invalid

What causes a B129A error code?

The most common causes of B129A include: Open or short circuit in LIN D bus wiring; Damage to connectors or corrosion of contacts; Fault in one of the modules connected to the LIN D bus; Problems with power supply or grounding of modules.

How do I fix a B129A diagnostic trouble code?

To fix B129A: Check the integrity of the LIN D bus wiring. Inspect connectors and contacts for damage or corrosion. Check power supply and grounding of connected modules. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B129A?

Limited driving only, diagnose soon

How much does it cost to fix B129A?

The estimated repair cost for B129A is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat