B3920 2015 GMC Sierra 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 2015 GMC Sierra 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.
Code B3920 2015 GMC Sierra Description
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.
What are the Possible Causes of the DTC B3920 2015 GMC Sierra?
- 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 2015 GMC Sierra?
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.
Code Tech Notes
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 2015 GMC Sierra 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.
Need more information about the B3920 2015 GMC Sierra code?
Need more information on how to fix the B3920 2015 GMC Sierra code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the B3920 2015 GMC Sierra code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about B3920 2015 GMC Sierra Code
1. What does the OBDII code B3920 mean on a 2015 GMC Sierra?
The B3920 code indicates an issue with the Seat Motors Group 1 Common Circuit, often related to a malfunction in the power seat motor or its wiring.
2. What are common symptoms of the B3920 code in a GMC Sierra?
Symptoms may include the power seat not moving in one or more directions, intermittent seat movement, or a complete failure of the seat adjustment system.
3. What causes the B3920 code to appear?
Common causes include faulty seat motor wiring, a damaged seat motor, a blown fuse, or a malfunctioning seat control module.
4. How can I diagnose the B3920 code on my 2015 GMC Sierra?
Start by inspecting the seat motor wiring and connectors for damage or corrosion. Use a scan tool to check for related codes and test the seat motor’s functionality.
5. Can a blown fuse trigger the B3920 code?
Yes, a blown fuse in the seat motor circuit can disrupt power and cause the B3920 code to be set.
6. Is it safe to drive with the B3920 code active?
Yes, the vehicle is still safe to drive, but the power seat adjustment may not work, which could affect comfort and driving ergonomics.
7. How do I fix the B3920 code on my GMC Sierra?
Repairs may involve replacing damaged wiring, cleaning corroded connections, replacing the seat motor, or reprogramming/updating the seat control module.
8. How much does it cost to fix the B3920 code on a 2015 GMC Sierra?
Repair costs vary depending on the issue, but replacing a seat motor typically costs between $200 and $500, while wiring repairs may cost less.
9. Can I clear the B3920 code without fixing the problem?
You can clear the code using an OBDII scanner, but it will likely return unless the underlying issue is resolved.
10. Do I need a professional mechanic to fix the B3920 code?
While basic inspections can be done at home, complex repairs like motor replacement or module programming may require professional assistance.
Discuss the causes and fixes for B3920 2015 GMC Sierra OBDII Code
Code B3920 2015 GMC Sierra comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
