AutoCodes – GMC – B3920 GMC

B3920 GMC Code - Seat Motors Group 1 Common Circuit

Quick Answer

The Seat Memory Control Module controls the seat, lumbar, and adjustable pedal motors via half bridges that are connected to power rails internal to the module. Common causes include Faulty Seat, Lumbar, or Adjustable Pedal Motors, Seat, Lumbar, or Adjustable Pedal Motors harness is open or shorted, Seat, Lumbar, or Adjustable Pedal Motors 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: B3920 GMC indicates Seat Motors Group 1 Common Circuit.
Common causes: Common causes include Faulty Seat, Lumbar, or Adjustable Pedal Motors, Seat, Lumbar, or Adjustable Pedal Motors harness is open or shorted, Seat, Lumbar, or Adjustable Pedal Motors 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 3,100

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 Jun 16, 2023

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code B3920 GMC Description

The Seat Memory Control Module controls the seat, lumbar, and adjustable pedal motors via half bridges that are connected to power rails internal to the module. The Seat Memory Control Module connects all of the motor control circuits on each power rail to a common reference point whenever they are not in operation. The module monitors all seat motor control circuits for a shorted to ground or voltage before enabling any seat motor.
When a power seat, lumbar, or adjustable pedal switch is pressed or when a memory recall is requested, each seat motor receives battery voltage and ground from the seat memory control module via the motor control circuits. All motors are reversible, so the direction the motor rotates depends on which control circuit voltage is applied and which control circuit ground is applied. When the switch is operated in the opposite direction, the module reverses the polarity and applies voltage and ground to the opposite circuits to move the seat in the opposite direction.
The Diagnostic Trouble Code (DTC) sets when the voltage on any power rail 1 motor control circuit exceeds 2.78 volts for 100 ms or is below 1.47 volts for 100 ms.

OBDII Code B3920 GMC - Seat Motors Group 1 Common Circuit - AutoCodes.com — B3920 GMC Code - Seat Motors Group 1 Common Circuit

What does this mean?

What are the Possible Causes of the DTC B3920 GMC?

Faulty Seat, Lumbar, or Adjustable Pedal Motors
Seat, Lumbar, or Adjustable Pedal Motors harness is open or shorted
Seat, Lumbar, or Adjustable Pedal Motors circuit poor electrical connection
Faulty Seat Memory Control Module

How to Fix the DTC B3920 GMC?

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

B3920 01 Group 1 Seat Motors Circuit Shorted to Battery or Open
B3920 02 Group 1 Seat Motors Circuit Shorted to Ground

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B3920 GMC 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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Information for Specific GMC Models

B3920 2014 GMC Sierra — Seat Motors Group 1 Common Circuit
B3920 2015 GMC Sierra — Seat Motors Group 1 Common Circuit
B3920 2016 GMC Sierra — Seat Motors Group 1 Common Circuit
B3920 2017 GMC Sierra — Seat Motors Group 1 Common Circuit
B3920 2018 GMC Sierra — Seat Motors Group 1 Common Circuit

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 B3920 GMC Code

1. What are the common symptoms of OBDII code B3920 GMC related to the Seat Motors Group 1 Common Circuit?

- Common symptoms include non-functioning seat motors, inability to adjust seat positions, and inoperative seat memory functions.

2. What are some possible causes of OBDII code B3920 GMC for the Seat Motors Group 1 Common Circuit?

- Potential causes include faulty seat motor components, damaged wiring or connectors, and issues with the seat control module.

3. How can I diagnose OBDII code B3920 GMC for the Seat Motors Group 1 Common Circuit?

- Diagnosis involves using a scan tool to retrieve the specific fault code, conducting a visual inspection of seat motor components, and testing the wiring and connectors for continuity.

4. What are some tips for repairing OBDII code B3920 GMC related to the Seat Motors Group 1 Common Circuit?

- Repair tips include repairing or replacing damaged wiring, connectors, or seat motor components, resetting the seat control module, and ensuring proper seat calibration.

5. Can OBDII code B3920 GMC for the Seat Motors Group 1 Common Circuit be fixed without professional help?

- While some basic troubleshooting and repairs can be done by DIY enthusiasts, complex issues may require the expertise of a professional mechanic familiar with automotive electronics.

6. Is it safe to continue driving with OBDII code B3920 GMC triggered for the Seat Motors Group 1 Common Circuit?

- It is not recommended to drive with this code active, as it may affect the functionality of the seat adjustment system, potentially compromising driver comfort and safety.

7. How can I prevent OBDII code B3920 GMC from recurring in the future?

- Regular maintenance of the seat adjustment system, avoiding overloading the seats, and addressing any issues promptly can help prevent the recurrence of this fault code.

8. Will resetting the OBDII code B3920 GMC for the Seat Motors Group 1 Common Circuit solve the issue?

- Resetting the code may temporarily clear the warning light, but if the underlying issue is not addressed, the code is likely to reappear once the system detects the fault again.

9. Are there any recalls or technical service bulletins related to OBDII code B3920 GMC and the Seat Motors Group 1 Common Circuit?

- It is recommended to check with the vehicle manufacturer or authorized service centers for any relevant recalls or technical service bulletins addressing this specific fault code.

10. Can weather conditions or environmental factors trigger OBDII code B3920 GMC for the Seat Motors Group 1 Common Circuit?

- Extreme temperatures, moisture exposure, or other environmental factors can contribute to electrical issues that may trigger this fault code. Regular inspection and maintenance can help mitigate these risks.