OBD Guide

B3125

Driver Door Only Unlock Circuit

B3125 is an OBD-II diagnostic trouble code meaning: Driver Door Only Unlock Circuit. Common causes: open or short circuit in wiring harness, solenoid valve malfunction. Estimated repair cost: $56–167.

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

Symptoms

  • The driver's door does not open when the button is pressed
  • The driver's door opens with a delay
  • Other doors work fine

Causes

  • Open or short circuit in wiring harness
  • Solenoid valve malfunction
  • Problems with the door control unit
  • Contact corrosion

How to Fix

  1. Check the wiring harness for opens and shorts
  2. Check the operation of the solenoid valve
  3. Diagnose the door control unit
  4. Clean contacts from corrosion

Related codes

Error B3125 by Vehicle Brand

FAQ

What does the B3125 code mean?

B3125 is an OBD-II diagnostic trouble code that indicates: Driver Door Only Unlock Circuit

What causes a B3125 error code?

The most common causes of B3125 include: Open or short circuit in wiring harness; Solenoid valve malfunction; Problems with the door control unit; Contact corrosion.

How do I fix a B3125 diagnostic trouble code?

To fix B3125: Check the wiring harness for opens and shorts. Check the operation of the solenoid valve. Diagnose the door control unit. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B3125?

Limited driving only, diagnose soon

How much does it cost to fix B3125?

The estimated repair cost for B3125 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

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