AutoCodes – GMC – B305C GMC

B305C GMC Code - Immobilizer Transponder Of Wrong Type Programmed

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: B305C GMC indicates Immobilizer Transponder Of Wrong Type Programmed.
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 469

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 03, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B305C GMC 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.CM.

OBDII Code B305C GMC - Immobilizer Transponder Of Wrong Type Programmed - AutoCodes.com — B305C GMC Code - Immobilizer Transponder Of Wrong Type Programmed

What does this mean?

What are the Possible Causes of the DTC B305C GMC?

Faulty Key/Transmitter
Faulty Body Control Module (BCM)

How to Fix the DTC B305C 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 B305C 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 B305C GMC Code

1. What are common symptoms of OBDII code B305C GMC (Immobilizer Transponder Of Wrong Type Programmed)?

- Common symptoms include difficulty starting the vehicle, the engine not turning over, and the vehicle going into an anti-theft mode.

2. What causes the OBDII code B305C GMC to appear?

- The code B305C typically appears when the vehicle's immobilizer system detects that the wrong type of transponder key has been programmed.

3. How can I troubleshoot the OBDII code B305C GMC?

- To troubleshoot this code, check if the correct transponder key is being used, ensure the key is in good condition, and inspect the immobilizer system for any faults.

4. Can using the wrong type of key cause the OBDII code B305C GMC to trigger?

- Yes, using an incorrect or incompatible transponder key is a common cause of the B305C code being triggered by the vehicle's immobilizer system.

5. Is it possible to reset the OBDII code B305C GMC without professional help?

- In some cases, you may be able to reset the B305C code by disconnecting the vehicle's battery for a few minutes. However, it is recommended to have the issue properly diagnosed and repaired.

6. How can I prevent the OBDII code B305C GMC from reoccurring?

- To prevent the B305C code from reoccurring, always use the correct transponder key for your vehicle, avoid using damaged keys, and ensure the key is properly programmed.

7. Can a malfunctioning immobilizer system cause the OBDII code B305C GMC to be triggered?

- Yes, if there is a fault in the vehicle's immobilizer system, such as a damaged transceiver or control module, it can lead to the appearance of the B305C code.

8. Are there any DIY repair tips for fixing the OBDII code B305C GMC?

- DIY repair tips may include checking and replacing the transponder key, ensuring proper key programming, and inspecting the immobilizer system wiring for any issues.

9. How can a mechanic diagnose the OBDII code B305C GMC?

- A mechanic can diagnose the B305C code using a professional OBDII scanner to read the code, inspect the immobilizer system components, and test the transponder key for compatibility.

10. Is it safe to continue driving with the OBDII code B305C GMC present?

- It is not recommended to drive with the B305C code present, as it may lead to starting issues or the vehicle going into anti-theft mode. It is best to address the issue promptly.