OBD Guide

B3634

Head-Up Display Dimming Switch Circuit

B3634 is an OBD-II diagnostic trouble code meaning: Head-Up Display Dimming Switch Circuit. Common causes: break in the wiring harness, 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

  • Non-adjustable head-up display brightness
  • Head-up display won't turn on
  • Display flashing

Causes

  • Break in the wiring harness
  • Short circuit in the circuit
  • Brightness switch malfunction
  • Damage to the head-up display
  • Control unit software failure

How to Fix

  1. Check the continuity of the wiring harness in the dimming control circuit.
  2. Test the brightness switch for malfunction
  3. Diagnose the HUD block for errors
  4. If necessary, replace damaged components
  5. Reset the error and check the system

Related codes

Error B3634 by Vehicle Brand

FAQ

What does the B3634 code mean?

B3634 is an OBD-II diagnostic trouble code that indicates: Head-Up Display Dimming Switch Circuit

What causes a B3634 error code?

The most common causes of B3634 include: Break in the wiring harness; Short circuit in the circuit; Brightness switch malfunction; Damage to the head-up display.

How do I fix a B3634 diagnostic trouble code?

To fix B3634: Check the continuity of the wiring harness in the dimming control circuit.. Test the brightness switch for malfunction. Diagnose the HUD block for errors. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B3634?

Limited driving only, diagnose soon

How much does it cost to fix B3634?

The estimated repair cost for B3634 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat