AutoCodes – GMC – B3387 GMC

B3387 GMC Code - Right Front Window Up Switch Circuit Low

Quick Answer

The window switch or window switch circuits that generate this Diagnostic Trouble Code (DTC) are built-in parts of the Driver Door Switch Assembly (DDSA). Common causes include Faulty Driver Door Switch Assembly (DDSA), Driver Door Switch Assembly (DDSA) harness is open or shorted, Driver Door Switch Assembly (DDSA) 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: B3387 GMC indicates Right Front Window Up Switch Circuit Low.
Common causes: Common causes include Faulty Driver Door Switch Assembly (DDSA), Driver Door Switch Assembly (DDSA) harness is open or shorted, Driver Door Switch Assembly (DDSA) 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 492

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Mar 06, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B3387 GMC Description

The window switch or window switch circuits that generate this Diagnostic Trouble Code (DTC) are built-in parts of the Driver Door Switch Assembly (DDSA). There are no external circuits. The DDSA internally supplies power and ground to the contacts of each of the integral window switches. When one of the switches is operated, the switch contacts close, providing the DDSA with a specific window switch signal. The DDSA processes this signal, assigns a digital message to it, and sends the message to the appropriate Driver Door Module (DDM), Passenger Front Door Module (PDM), Left Rear Door Module (LRDM), or Right Rear Door Module (RRDM), via the class 2 serial data circuit. The door module, upon receiving the message, examines other relevant information available on the class 2 serial data line in order to determine if conditions are correct for window operation to occur. If conditions are correct, the door module applies power and ground to the associated window motor and circuits in order to move the window. If the DDSA determines that one of its built in window switches is closed for more than 15 continuous seconds, it sets the DTC.

OBDII Code B3387 GMC - Right Front Window Up Switch Circuit Low - AutoCodes.com — B3387 GMC Code - Right Front Window Up Switch Circuit Low

What does this mean?

What are the Possible Causes of the DTC B3387 GMC?

Faulty Driver Door Switch Assembly (DDSA)
Driver Door Switch Assembly (DDSA) harness is open or shorted
Driver Door Switch Assembly (DDSA) circuit poor electrical connection
Faulty Passenger Front Door Module (PDM)
Faulty Driver Door Module (DDM)

How to Fix the DTC B3387 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 B3387 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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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 B3387 GMC Code

1. What does the OBDII code B3387 mean on a GMC vehicle?

The B3387 code indicates a "Right Front Window Up Switch Circuit Low," meaning thereâ€™s a problem in the electrical circuit for the right front window's "up" switch.

2. What are the symptoms of the B3387 code on a GMC?

Symptoms may include the right front window not rolling up, intermittent operation of the window, or the window switch not responding.

3. What causes the B3387 code to appear?

Common causes include a faulty window switch, damaged wiring or connectors in the circuit, or a malfunctioning window motor.

4. How do I diagnose the B3387 code on my GMC?

Start by inspecting the window switch, checking for damaged wires or loose connections, and testing the circuit with a multimeter to verify voltage and continuity.

5. Can a faulty window motor trigger the B3387 code?

Yes, if the window motor is drawing too much current or failing to respond, it can cause the circuit to register a low voltage, triggering this code.

6. Is it safe to drive with the B3387 code on a GMC?

Yes, itâ€™s generally safe to drive, but the right front window may not function properly, potentially causing inconvenience or safety concerns.

7. How can I fix the B3387 code on my GMC?

Repairs may involve replacing the window switch, repairing damaged wiring, cleaning corroded connectors, or replacing the window motor if necessary.

8. What tools are needed to fix the B3387 code?

Youâ€™ll typically need a multimeter, wiring diagrams, and potentially basic tools like a screwdriver and pliers to remove panels and access the switch or motor.

9. Can a blown fuse cause the B3387 code?

While a blown fuse can affect the window circuit, it typically wouldnâ€™t cause this specific code, which points to a low voltage issue in the switch circuit.

10. Do I need to clear the code after repairs?

Yes, after completing repairs, use an OBDII scanner to clear the code and verify that it doesnâ€™t return during operation.