OBD Guide
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B1128

Driver Side Door Lock Switch Signal Error

B1128 is an OBD-II diagnostic trouble code meaning: Driver Side Door Lock Switch Signal Error. Common causes: door lock switch malfunction, open or shorted wiring harness. Estimated repair cost: $22–111.

Severity
⚠️ Medium
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$22–111 (est.)

Symptoms

  • Incorrect operation of the central locking
  • The driver's door does not open/close using the remote control
  • It is impossible to lock/unlock the door using the button inside the cabin

Causes

  • Door lock switch malfunction
  • Open or shorted wiring harness
  • Poor contact in connectors
  • Door control module malfunction

How to Fix

  1. Check the operation of the door lock switch
  2. Inspect the wiring harness for damage
  3. Check contacts in connectors
  4. Test the door control module
  5. Replace the faulty component

Related codes

B1129B1130B1131

FAQ

What does the B1128 code mean?

B1128 is an OBD-II diagnostic trouble code that indicates: Driver Side Door Lock Switch Signal Error

What causes a B1128 error code?

The most common causes of B1128 include: Door lock switch malfunction; Open or shorted wiring harness; Poor contact in connectors; Door control module malfunction.

How do I fix a B1128 diagnostic trouble code?

To fix B1128: Check the operation of the door lock switch. Inspect the wiring harness for damage. Check contacts in connectors. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B1128?

Do not drive — repair immediately

How much does it cost to fix B1128?

The estimated repair cost for B1128 is $22–111. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat