AutoCodes – Buick – B320C Buick

B320C Buick Code - Middle Door Window Motor

Quick Answer

The front door, rear door and middle door power window motors communicate with the Drivers Door Module (DDM), Passenger Door Module (PDM) and Rear Door Modules and Middle Door Modules over the LIN BUS. Common causes include Faulty Middle Door Window Motor, Middle Door Window Motor harness is open or shorted, Middle Door Window Motor 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: B320C Buick indicates Middle Door Window Motor.
Common causes: Common causes include Faulty Middle Door Window Motor, Middle Door Window Motor harness is open or shorted, Middle Door Window Motor 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 459

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 Mar 05, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code B320C Buick Description

The front door, rear door and middle door power window motors communicate with the Drivers Door Module (DDM), Passenger Door Module (PDM) and Rear Door Modules and Middle Door Modules over the LIN BUS. The motors contain a logic module which must be normalized or programmed any time the window motor is serviced to provide proper operation and communication between door modules and window motors. The Diagnostic Trouble Code (DTC) sets when an internal malfunction has been detected by the DDM or PDM in the Front Door, Rear Door, or Middle Door window motor while commanding the window motor UP/DOWN.

OBDII Code B320C Buick - Middle Door Window Motor - AutoCodes.com — B320C Buick Code - Middle Door Window Motor

What does this mean?

What are the Possible Causes of the DTC B320C Buick?

Faulty Middle Door Window Motor
Middle Door Window Motor harness is open or shorted
Middle Door Window Motor circuit poor electrical connection
Faulty Middle Door Module

How to Fix the DTC B320C Buick?

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 does this mean?

Code Tech Notes

B320C 39 Middle Door Window Motor Internal Electronic Failure/Discard
B320C 42 Middle Door Window Motor Calibration Data Set Not Programmed
B320C 4B Middle Door Window Motor Calibration Not Learned

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B320C Buick 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 B320C Buick Code

1. What does the OBDII code B320C mean on a Buick?

The B320C code indicates an issue with the middle door window motor, which may involve a malfunction in the motor itself or its related circuitry.

2. What are the common symptoms of the B320C code on a Buick?

Symptoms may include the middle door window not operating, unusual noises from the motor, or erratic window movement.

3. What causes the B320C code to appear on a Buick?

Common causes include a faulty window motor, damaged wiring, a blown fuse, or a malfunctioning control switch.

4. How do I diagnose the B320C code on a Buick?

Start by checking the fuse and wiring for damage, test the window motor with a multimeter, and inspect the control switch for proper functionality.

5. Can I drive my Buick with the B320C code?

Yes, you can drive the vehicle, but the affected window may not function until the issue is resolved, which could be inconvenient.

6. How do I fix the B320C code on a Buick?

Repairs may involve replacing the window motor, repairing damaged wiring, or replacing a faulty control switch.

7. How much does it cost to fix the B320C code on a Buick?

The cost can range from $100 to $300 depending on whether the motor, wiring, or switch needs replacement and labor costs.

8. Can a blown fuse cause the B320C code on a Buick?

Yes, a blown fuse in the window motor circuit can trigger the B320C code and prevent the window from operating.

9. What tools do I need to troubleshoot the B320C code on a Buick?

You may need a multimeter, a basic socket set, and access to the vehicle's wiring diagram for proper diagnostics.

10. Is it necessary to reprogram anything after fixing the B320C code on a Buick?

In most cases, reprogramming is not required, but you may need to reset the code using an OBDII scanner after completing the repair.

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