AutoCodes – Generic – B3596

B3596 Code - Hazard Lamps Request Circuit Malfunction

Quick Answer

The hazard flashers may be activated in any power mode. Common causes include Faulty Turn Signal/Multifunction Switch, Turn Signal/Multifunction Switch harness is open or shorted, Turn Signal/Multifunction 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: B3596 indicates Hazard Lamps Request Circuit Malfunction.
Common causes: Common causes include Faulty Turn Signal/Multifunction Switch, Turn Signal/Multifunction Switch harness is open or shorted, Turn Signal/Multifunction 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.

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Code Popularity 2,998

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 Jun 13, 2023

Description
Possible Causes
How To Fix
Tech Notes ▶
Cost to Diagnose
FAQs
Comments
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Code B3596 Description

The hazard flashers may be activated in any power mode. The hazard warning switch signal circuit is momentarily grounded when the hazard warning switch is pressed. The Body Control Module (BCM) responds to the hazard warning switch signal input by supplying battery voltage to all four turn signal lamps in an ON and OFF duty cycle. When the hazard warning switch is activated, the BCM sends a serial data message to the instrument cluster requesting both turn signal indicators to be cycled ON and OFF. The Diagnostic Trouble Code (DTC) sets when the BCM detects a short to ground in the hazard warning switch signal circuit.

OBDII Code B3596 - Hazard Lamps Request Circuit Malfunction - AutoCodes.com — B3596 Code - Hazard Lamps Request Circuit Malfunction

What does this mean?

What are the Possible Causes of the DTC B3596?

Faulty Turn Signal/Multifunction Switch
Turn Signal/Multifunction Switch harness is open or shorted
Turn Signal/Multifunction Switch circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B3596?

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 does this mean?

Code Tech Notes

User Submitted Video

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B3596 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 B3596 code?

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Need Help with the Code?

Get the B3596 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B3596 Buick — Hazard Lamps Request Circuit Malfunction
B3596 Cadillac — Hazard Lamps Request Circuit Malfunction
B3596 Chevrolet — Hazard Lamps Request Circuit Malfunction
B3596 GMC — Hazard Lamps Request Circuit Malfunction

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 B3596 Code

1. What does OBDII code B3596 mean?

B3596 indicates a malfunction in the hazard lamps request circuit, which controls the activation of the vehicle's hazard warning lights.

2. What are the common symptoms of code B3596?

Symptoms may include hazard lights not functioning, hazard lights staying on continuously, or intermittent operation of the hazard lamps.

3. What causes the B3596 code to appear?

Common causes include a faulty hazard light switch, damaged wiring or connectors in the circuit, or a malfunctioning body control module (BCM).

4. Can a blown fuse trigger code B3596?

Yes, a blown fuse related to the hazard lamp circuit can cause this code, as it disrupts the electrical flow to the system.

5. How is the B3596 code diagnosed?

A technician will inspect the hazard light switch, check for damaged wiring or connectors, and use a scan tool to monitor the circuit's performance and detect faults.

6. Can I still drive my car with the B3596 code active?

Yes, but it is not recommended, as the hazard lights are a critical safety feature for signaling emergencies or roadside stops.

7. How can I fix code B3596?

Repairs may involve replacing the hazard light switch, repairing damaged wires or connectors, or reprogramming or replacing the BCM if necessary.

8. What tools are needed to diagnose the B3596 code?

A scan tool capable of reading body control module codes, a multimeter for checking electrical continuity, and basic hand tools are typically required.

9. Is the B3596 code specific to certain vehicles?

No, B3596 can appear on a variety of vehicles with OBDII systems, but the exact components involved may vary by manufacturer.

10. How much does it cost to repair the B3596 code?

Repair costs vary depending on the issue but can range from $50 for a simple switch replacement to several hundred dollars if BCM replacement is required.