AutoCodes – Generic – U0221

U0221 Code - Lost Communication With Door Switch Module 'G'

Quick Answer

A Controller Area Network (CAN) is a vehicle bus standard designed to interconnect automotive devices without a host computer. Common causes include Faulty Door Switch Module 'G', Door Switch Module 'G' harness is open or shorted, Door Switch Module 'G' circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: U0221 indicates Lost Communication With Door Switch Module 'G'.
Common causes: Common causes include Faulty Door Switch Module 'G', Door Switch Module 'G' harness is open or shorted, Door Switch Module 'G' circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 1,903

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Apr 03, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U0221 Description

A Controller Area Network (CAN) is a vehicle bus standard designed to interconnect automotive devices without a host computer. Operating information and commands are exchanged among the devices. The devices have programmed information about what messages are needed to be exchanged on the serial data circuits. CAN bus uses two dedicated wires for communication. The wires are called CAN high and CAN low. When the CAN bus is in idle mode, both lines carry 2.5V. When data bits are being transmitted, the CAN high line goes to 3.75V, and the CAN low drops to 1.25V, thereby generating a 2.5V differential between the lines. Since communication relies on a voltage differential between the two bus lines, the CAN bus is NOT sensitive to inductive spikes, electrical fields, or other noise. The Diagnostic Trouble Code (DTC) sets when a periodic message from the Door Switch Module 'G' has not been received.

OBDII Code U0221 - Lost Communication With Door Switch Module 'G' - AutoCodes.com — U0221 Code - Lost Communication With Door Switch Module 'G'

What does this mean?

What are the Possible Causes of the DTC U0221?

Faulty Door Switch Module 'G'
Door Switch Module 'G' harness is open or shorted
Door Switch Module 'G' circuit poor electrical connection

How to Fix the DTC U0221?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U0221 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about U0221 Code

1. What does the OBDII code U0221 mean?

U0221 indicates that the vehicle's control modules have lost communication with Door Switch Module 'G.'

2. What are the common symptoms of code U0221?

Symptoms may include non-functional power door locks, windows, or mirrors, and an illuminated check engine or warning light.

3. What causes the U0221 code to appear?

Common causes include faulty wiring or connectors, a malfunctioning Door Switch Module 'G,' or issues with the CAN (Controller Area Network) bus system.

4. Can I drive my car with the U0221 code?

While the car may still be drivable, features like power door locks or windows may not work, which can be inconvenient and a potential safety issue.

5. How can I diagnose code U0221?

Start by inspecting the wiring and connectors to Door Switch Module 'G,' then check for continuity in the CAN bus system and test the module itself for functionality.

6. How do I fix the U0221 code?

Repairs may include replacing or repairing damaged wiring, reconnecting loose connectors, or replacing a faulty Door Switch Module 'G.'

7. Can a weak battery cause the U0221 code?

Yes, a weak or failing battery can cause communication errors between modules, including U0221.

8. Is it expensive to fix code U0221?

Repair costs vary depending on the issue. Replacing a module or repairing wiring can range from $100 to $500 or more, depending on labor and parts.

9. Will clearing the U0221 code with a scan tool fix the problem?

Clearing the code may temporarily turn off the warning light, but the underlying issue must be resolved to prevent the code from returning.

10. What vehicles are most commonly affected by code U0221?

Code U0221 can occur in any vehicle equipped with a CAN bus system and Door Switch Module 'G,' but the specific make and model of affected vehicles will depend on the manufacturer.