AutoCodes – Chevrolet – B1850 Chevrolet

B1850 Chevrolet Code - Driver Seat Lumbar Position Sensor Circuit

Quick Answer

The Driver Seat Module (DSM) monitors the positions of most of the seat adjuster motors using hall effect type position sensors. Common causes include Faulty Driver Seat Lumbar Position Sensor, Driver Seat Lumbar Position Sensor harness is open or shorted, Driver Seat Lumbar Position Sensor 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: B1850 Chevrolet indicates Driver Seat Lumbar Position Sensor Circuit.
Common causes: Common causes include Faulty Driver Seat Lumbar Position Sensor, Driver Seat Lumbar Position Sensor harness is open or shorted, Driver Seat Lumbar Position Sensor 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 4,216

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 Jul 31, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1850 Chevrolet Description

The Driver Seat Module (DSM) monitors the positions of most of the seat adjuster motors using hall effect type position sensors. The hall effect position sensors are supplied with battery positive reference and ground circuits from the DSM. The position sensor signal circuits are supplied battery positive voltage through a resistor then monitored within the DSM. During adjuster motor operation the hall effect position sensor provides a single pulse for every adjuster motor shaft rotation. The DSM counts the pulses from the position sensor signal circuits to determine the adjuster motor positions when storing or recalling memory seat position settings.

OBDII Code B1850 Chevrolet - Driver Seat Lumbar Position Sensor Circuit - AutoCodes.com — B1850 Chevrolet Code - Driver Seat Lumbar Position Sensor Circuit

What does this mean?

What are the Possible Causes of the DTC B1850 Chevrolet?

Faulty Driver Seat Lumbar Position Sensor
Driver Seat Lumbar Position Sensor harness is open or shorted
Driver Seat Lumbar Position Sensor circuit poor electrical connection
Faulty Driver Seat Module (DSM)

How to Fix the DTC B1850 Chevrolet?

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 B1850 Chevrolet 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 B1850 Chevrolet Code

1. What does the OBDII code B1850 mean on a Chevrolet?

The code B1850 indicates an issue with the driver seat lumbar position sensor circuit, which monitors and adjusts the lumbar support in the driverâ€™s seat.

2. What are the common symptoms of the B1850 code?

Symptoms may include lumbar support not working, lumbar adjustments being unresponsive, or an illuminated airbag or diagnostic warning light on the dashboard.

3. What causes the B1850 code to appear?

Common causes include a faulty lumbar position sensor, damaged sensor wiring, loose electrical connections, or a malfunctioning seat control module.

4. Can I drive with the B1850 code active?

Yes, the vehicle is typically safe to drive, but the lumbar support adjustment may not function properly, reducing comfort for the driver.

5. How do you diagnose the B1850 code?

Diagnosis involves using an OBDII scanner to confirm the code, visually inspecting the wiring and connectors, and testing the lumbar position sensor for proper operation.

6. What are the most likely fixes for the B1850 code?

Repairs may include replacing the lumbar position sensor, repairing damaged wiring, securing loose connections, or reprogramming or replacing the seat control module.

7. How much does it cost to fix the B1850 code?

Repair costs vary but typically range from $100 to $300, depending on whether the sensor or wiring needs replacement and labor rates.

8. Can I fix the B1850 code myself?

If you have basic automotive repair skills, you can check for loose connections or damaged wiring, but sensor replacement or module reprogramming may require professional help.

9. Does the B1850 code affect other vehicle systems?

In some cases, it could interfere with features controlled by the same module, but it generally does not impact critical systems like the engine or brakes.

10. How can I prevent the B1850 code from occurring again?

Regularly inspect the seatâ€™s wiring and connectors for damage or wear, and avoid applying excessive force to the lumbar adjustment mechanism.