OBD Guide

B3820

Left Rear Window Down Control Circuit

B3820 is an OBD-II diagnostic trouble code meaning: Left Rear Window Down Control Circuit. Common causes: open or short circuit in wiring harness, window lift motor malfunction. Estimated repair cost: $56–167.

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

Symptoms

  • The left rear window does not go down
  • Intermittent operation of the window regulator
  • The malfunction indicator on the instrument panel lights up

Causes

  • Open or short circuit in wiring harness
  • Window lift motor malfunction
  • Problems in the power window control unit
  • Contact corrosion
  • Mechanical obstacles in the window lift mechanism

How to Fix

  1. Check the wiring harness for breaks and short circuits
  2. Check the window lift motor
  3. Inspect contacts for corrosion
  4. Check the window lift mechanism for mechanical obstructions.
  5. If necessary, replace faulty components

Related codes

Error B3820 by Vehicle Brand

FAQ

What does the B3820 code mean?

B3820 is an OBD-II diagnostic trouble code that indicates: Left Rear Window Down Control Circuit

What causes a B3820 error code?

The most common causes of B3820 include: Open or short circuit in wiring harness; Window lift motor malfunction; Problems in the power window control unit; Contact corrosion.

How do I fix a B3820 diagnostic trouble code?

To fix B3820: Check the wiring harness for breaks and short circuits. Check the window lift motor. Inspect contacts for corrosion. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B3820?

Limited driving only, diagnose soon

How much does it cost to fix B3820?

The estimated repair cost for B3820 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat