◆OBD Codes

B0221

Rear Window Defogger Circuit Open

Lowelectrical

Overview

The B0221 code indicates that the body control module has detected a rear window defogger circuit open condition. This relates to the vehicle's body electrical systems, which control comfort, convenience, and safety features. When this code is stored, the affected system or component may not operate correctly, potentially impacting safety or comfort features.

Symptoms

  • Erratic gauge readings
  • Multiple warning lights on dashboard
  • Vehicle not starting or cranking slowly
  • Intermittent electrical failures

Common Causes

  • Short or open circuit in wiring
  • Low battery voltage or failing battery
  • Failed relay or fuse
  • Water damage to electrical connectors

Diagnosis Steps

  1. 1Connect an OBD-II scanner and read all stored trouble codes and freeze frame data
  2. 2Check battery voltage and charging system output with a multimeter
  3. 3Inspect wiring and connectors related to the trouble code
  4. 4Test circuit voltage, ground, and resistance with a multimeter
  5. 5Check related fuses and relays

Estimated Repair Cost

$75 — $400

Cost varies by vehicle, location, and repair shop. Includes parts and labor.

Commonly Affected Vehicles

GMC CanyonRam 1500Nissan TitanFord F-150

Related Codes

P0120P0340P0560

More Electrical Codes

B0001Driver Frontal Airbag Deployment Loop Circuit Open
Critical
B0002Driver Frontal Airbag Deployment Loop Circuit Short to Ground
Critical
B0003Driver Frontal Airbag Deployment Loop Circuit Short to Battery
Critical
B0004Driver Frontal Airbag Deployment Loop Resistance Too High
Critical
B0005Driver Frontal Airbag Deployment Loop Resistance Too Low
Critical
B0006Passenger Frontal Airbag Deployment Loop Circuit Open
Critical

Frequently Asked Questions

Electrical codes can be challenging because they often involve intermittent issues. A thorough inspection of wiring, connectors, and grounds with a multimeter is essential for accurate diagnosis.