B3920 2018 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 2018 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 2018 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 2018 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 2018 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 2018 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.
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Frequently Asked Questions about B3920 2018 GMC Sierra Code
1. What does the OBDII code B3920 mean on a 2018 GMC Sierra?
B3920 indicates an issue with the Seat Motors Group 1 Common Circuit, which involves the electrical system controlling seat movement.
2. What are common symptoms of code B3920 in a 2018 GMC Sierra?
Symptoms may include non-functional seat adjustments, limited movement of the seat, or intermittent operation of seat motors.
3. What causes code B3920 in a GMC Sierra?
Common causes include damaged wiring, a malfunctioning seat motor, a faulty control module, or poor electrical connections in the seat circuit.
4. How can I diagnose code B3920 on my 2018 GMC Sierra?
Use an OBDII scanner to confirm the code, then inspect the wiring, connectors, and seat motor for visible damage or loose connections.
5. Can a blown fuse cause the B3920 code in a GMC Sierra?
Yes, a blown seat circuit fuse can disrupt power to the seat motors and trigger the B3920 code.
6. Is it safe to drive my 2018 GMC Sierra with the B3920 code active?
Yes, the code does not impact vehicle drivability but may affect seat adjustment functionality, which could be inconvenient.
7. How do I repair the B3920 code on a 2018 GMC Sierra?
Repairs may include fixing or replacing damaged wiring, connectors, or the seat motor itself, and ensuring all connections are secure.
8. Can a faulty seat control module trigger code B3920?
Yes, a malfunctioning seat control module can cause the code if it fails to properly communicate with or power the seat motors.
9. How much does it cost to fix the B3920 code on a GMC Sierra?
Repair costs can vary widely, ranging from $50 for simple wiring fixes to several hundred dollars if the seat motor or control module needs replacement.
10. Will clearing the B3920 code solve the problem permanently?
Clearing the code may temporarily remove it, but if the underlying issue is not addressed, the code is likely to return.
Discuss the causes and fixes for B3920 2018 GMC Sierra OBDII Code
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