AutoCodes – Chevrolet – B3935 Chevrolet

B3935 Chevrolet 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 Chevrolet 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.

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Code Popularity 17,390

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
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Code B3935 Chevrolet 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 Chevrolet - Transponder Authentication - AutoCodes.com — B3935 Chevrolet Code - Transponder Authentication

What does this mean?

What are the Possible Causes of the DTC B3935 Chevrolet?

Faulty Key/Transmitter
Faulty Body Control Module (BCM)

How to Fix the DTC B3935 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 B3935 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.

Need more information about the B3935 Chevrolet code?

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

Need Help with the Code?

Get the B3935 Chevrolet code diagnosed by a professional: Find a repair shop in your area

Information for Specific Chevrolet Models

B3935 2014 Chevrolet Silverado — Transponder Authentication
B3935 2015 Chevrolet Silverado — Transponder Authentication
B3935 2016 Chevrolet Silverado — Transponder Authentication
B3935 2017 Chevrolet Silverado — Transponder Authentication
B3935 2018 Chevrolet Silverado — Transponder Authentication

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 Chevrolet Code

1. What are the common symptoms of OBDII code B3935 (Chevrolet) related to Transponder Authentication?

The common symptoms include difficulty starting the vehicle, the engine not turning over, and the security light staying illuminated on the dashboard.

2. What does the OBDII code B3935 (Chevrolet) Transponder Authentication indicate?

This code indicates a problem with the transponder authentication process, which is the system that verifies the key being used to start the vehicle matches the one programmed into the car's computer.

3. What are the possible causes of OBDII code B3935 (Chevrolet) related to Transponder Authentication?

Possible causes include a faulty key or key fob, a damaged transponder antenna, a problem with the immobilizer system, or issues with the car's computer or wiring.

4. How can I diagnose the OBDII code B3935 (Chevrolet) Transponder Authentication issue?

Diagnosing this issue typically involves using a professional OBDII scanner to read the code, checking the key and key fob for damage, inspecting the transponder antenna for any issues, and testing the immobilizer system and related components.

5. Can I repair OBDII code B3935 (Chevrolet) Transponder Authentication issue myself?

While some DIY enthusiasts may attempt to address this issue, it is recommended to have a professional mechanic diagnose and repair the problem to ensure proper and accurate resolution.

6. Is it safe to continue driving with OBDII code B3935 (Chevrolet) related to Transponder Authentication?

It is not recommended to continue driving with this code present, as it can lead to potential starting or security issues that may leave you stranded.

7. How much does it typically cost to repair OBDII code B3935 (Chevrolet) Transponder Authentication issue?

The cost of repairing this issue can vary depending on the specific cause, but it may involve replacing a key or key fob, repairing or replacing the transponder antenna, or addressing other related components, which can range from a few hundred to a thousand dollars.

8. Can resetting the car's computer clear OBDII code B3935 (Chevrolet) related to Transponder Authentication?

Resetting the car's computer may temporarily clear the code, but if the underlying issue is not resolved, the code is likely to reappear once the problem is detected again during the transponder authentication process.

9. How long does it take to repair OBDII code B3935 (Chevrolet) Transponder Authentication issue?

The repair time can vary depending on the exact cause of the issue and the availability of parts, but it may take a few hours to a full day for a mechanic to diagnose and repair the problem.

10. Can a weak car battery cause OBDII code B3935 (Chevrolet) related to Transponder Authentication?

A weak car battery can potentially cause issues with the transponder authentication process, as it may not provide enough power for the system to function properly. It is recommended to ensure the car battery is in good condition when troubleshooting this code.