AutoCodes – Buick – B3935 Buick

B3935 Buick Code - Transponder Authentication

Quick Answer

When an ignition key is inserted into the ignition lock cylinder and the ignition is switched ON, the transponder embedded in the key is energized by the exciter coil surrounding the ignition lock cylinder. Common causes include Faulty Key/Transmitter, Faulty Body Control Module (BCM). 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: B3935 Buick indicates Transponder Authentication.
Common causes: Common causes include Faulty Key/Transmitter, Faulty Body Control Module (BCM).
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 1,185

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 Jun 17, 2023

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 B3935 Buick Description

When an ignition key is inserted into the ignition lock cylinder and the ignition is switched ON, the transponder embedded in the key is energized by the exciter coil surrounding the ignition lock cylinder. The transponder transmits a signal to the immobilizer control module. The immobilizer control module translates this signal to a serial data message which is sent to the Body Control Module (BCM). The BCM then compares this value to a value stored in memory. If the value is correct, the BCM will send the prerelease password via the serial data circuit to the Engine Control Module (ECM) If the learned key code does not match or a transponder value is not received, the BCM will send the start disable password to the ECM.

OBDII Code B3935 Buick - Transponder Authentication - AutoCodes.com — B3935 Buick Code - Transponder Authentication

What does this mean?

What are the Possible Causes of the DTC B3935 Buick?

Faulty Key/Transmitter
Faulty Body Control Module (BCM)

How to Fix the DTC B3935 Buick?

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 B3935 Buick 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 B3935 Buick code?

Need more information on how to fix the B3935 Buick code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B3935 Buick 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 B3935 Buick Code

1. What does OBDII code B3935 for Buick Transponder Authentication mean?

This code indicates a communication error between the vehicle's immobilizer system and the transponder key.

2. What are the common symptoms of OBDII code B3935 Buick Transponder Authentication?

Symptoms may include the inability to start the vehicle, the security light staying on, or the engine starting and then immediately shutting off.

3. What are possible causes of OBDII code B3935 relating to Buick Transponder Authentication?

Common causes include a faulty transponder key, issues with the immobilizer system, or wiring problems in the transponder key circuit.

4. How can I diagnose OBDII code B3935 Buick Transponder Authentication?

Diagnosis typically involves using a scan tool to retrieve the code, checking the transponder key for proper functioning, and inspecting the immobilizer system components.

5. Can I fix OBDII code B3935 Buick Transponder Authentication myself?

Depending on the specific cause, you may be able to fix this issue yourself by replacing the transponder key, troubleshooting wiring problems, or resetting the immobilizer system.

6. Is it safe to drive with OBDII code B3935 Buick Transponder Authentication present?

It is not recommended to drive the vehicle with this code as it may result in the vehicle not starting or potentially shutting off while driving.

7. How much does it typically cost to repair OBDII code B3935 Buick Transponder Authentication?

The cost of repair can vary depending on the exact cause of the issue, but it may range from replacing a transponder key to repairing the immobilizer system.

8. Can OBDII code B3935 Buick Transponder Authentication be reset without fixing the underlying issue?

Resetting the code without addressing the root cause will likely result in the issue recurring. It is important to diagnose and repair the problem to prevent further issues.

9. Are there any preventive measures to avoid OBDII code B3935 Buick Transponder Authentication?

Regular maintenance of the immobilizer system, ensuring proper operation of transponder keys, and avoiding damage to key components can help prevent this issue.

10. How long does it typically take to repair OBDII code B3935 Buick Transponder Authentication?

The repair time can vary based on the cause of the issue and the complexity of the repair, but it may range from a quick key replacement to more extensive troubleshooting and repairs of the immobilizer system.