OBD Guide
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B1100

Door Multiplex Control Unit

B1100 is an OBD-II diagnostic trouble code meaning: Door Multiplex Control Unit. Common causes: wiring harness damage, short circuit in the circuit. Estimated repair cost: $56–167.

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

Symptoms

  • Power windows don't work
  • Problems with central locking
  • Door lights flashing
  • Error on the dashboard

Causes

  • Wiring harness damage
  • Short circuit in the circuit
  • Door control unit malfunction
  • Contact corrosion
  • Software glitch

How to Fix

  1. Check wiring harness for damage
  2. Check contacts for corrosion
  3. Scan the control unit for errors
  4. Replace the control unit if necessary
  5. Update unit firmware

Related codes

B1101B1102B1103

FAQ

What does the B1100 code mean?

B1100 is an OBD-II diagnostic trouble code that indicates: Door Multiplex Control Unit

What causes a B1100 error code?

The most common causes of B1100 include: Wiring harness damage; Short circuit in the circuit; Door control unit malfunction; Contact corrosion.

How do I fix a B1100 diagnostic trouble code?

To fix B1100: Check wiring harness for damage. Check contacts for corrosion. Scan the control unit for errors. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B1100?

Limited driving only, diagnose soon

How much does it cost to fix B1100?

The estimated repair cost for B1100 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat