AutoCodes – GMC – B3187 GMC

B3187 GMC Code - Left Rear Window Down Switch Circuit Low

Quick Answer

This Diagnostic Trouble Code (DTC) is generated by a passenger door window switch or a passenger door window switch circuit. Common causes include Faulty Left Rear Window Switch, Left Rear Window Switch harness is open or shorted, Left Rear Window Switch 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: B3187 GMC indicates Left Rear Window Down Switch Circuit Low.
Common causes: Common causes include Faulty Left Rear Window Switch, Left Rear Window Switch harness is open or shorted, Left Rear Window Switch 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 480

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 04, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code B3187 GMC Description

This Diagnostic Trouble Code (DTC) is generated by a passenger door window switch or a passenger door window switch circuit. Each passenger door window switch is mounted to the trim panel of the appropriate passenger door. The circuits and contacts of each passenger door window switch receive battery voltage and ground from the corresponding door module, i.e. Front Passenger Door Module (PDM), Left Rear Door Module (LRDM), or Right Rear Door Module (RRDM). When a passenger door window switch is operated, the switch contacts close and the associated door module interprets the flow of voltage as a specific request to move the window up or down. If conditions are correct for window operation to occur, the door module then powers the associated window motor and circuits to move the window.

OBDII Code B3187 GMC - Left Rear Window Down Switch Circuit Low - AutoCodes.com — B3187 GMC Code - Left Rear Window Down Switch Circuit Low

What does this mean?

What are the Possible Causes of the DTC B3187 GMC?

Faulty Left Rear Window Switch
Left Rear Window Switch harness is open or shorted
Left Rear Window Switch circuit poor electrical connection
Faulty Left Rear Door Module (LRDM)

How to Fix the DTC B3187 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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B3187 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.

Need more information about the B3187 GMC code?

Need more information on how to fix the B3187 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B3187 GMC code diagnosed by a professional: Find a repair shop in your area

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 B3187 GMC Code

1. What are the common symptoms of OBDII code B3187 GMC?

- The common symptoms include the left rear window not functioning properly, the window being stuck in the down position, and issues with the window switch.

2. What are some possible causes of the B3187 GMC code?

- Possible causes include a faulty left rear window switch, damaged wiring or connectors in the circuit, or a defective window motor.

3. How can I diagnose the issue related to the Left Rear Window Down Switch Circuit Low code?

- Use a diagnostic scanner to read the code and perform a visual inspection of the left rear window switch, wiring, and connectors to look for any visible damage.

4. Can a DIY enthusiast repair the B3187 GMC code at home?

- Depending on the specific cause, DIY repairs may be possible, such as replacing a faulty switch or repairing damaged wiring. However, for complex issues, it's recommended to seek professional help.

5. Are there any quick fixes for the B3187 GMC code?

- In some cases, resetting the OBDII code using a scanner may temporarily resolve the issue, but it's important to address the underlying cause to prevent the code from reappearing.

6. Is it safe to continue driving with the B3187 GMC code triggered?

- It is generally safe to drive with this code, but it's important to address the issue promptly to avoid further damage to the window system or potential safety hazards.

7. How much does it typically cost to repair the Left Rear Window Down Switch Circuit Low issue?

- Repair costs can vary depending on the cause of the problem, but it may range from a simple switch replacement costing around $50 to more complex repairs involving wiring or motor replacement costing several hundred dollars.

8. Will resetting the OBDII code make it go away permanently?

- Resetting the code without fixing the underlying issue will not make it go away permanently. The code is likely to reappear once the problem persists.

9. Can extreme weather conditions cause the B3187 GMC code to trigger?

- Extreme weather conditions can potentially exacerbate existing issues with the window switch circuit, leading to the triggering of the B3187 code.

10. How long does it typically take to repair the Left Rear Window Down Switch Circuit Low problem?

- Repair times can vary based on the complexity of the issue and the availability of parts, but simple repairs like switch replacement may take an hour or two, while more involved repairs could take longer.