B1359 DTC Code: Diagnosis, Causes, and Solutions


In the world of automotive diagnostics, DTC codes (Diagnostic Trouble Codes) play a significant role in identifying and resolving issues with vehicles. One such code is the B1359 DTC code, which is commonly encountered by mechanics and car owners. In this article, we will delve into the specifics of the B1359 code, its possible causes, and potential solutions to rectify the problem. So, let’s explore this DTC code in detail.

Understanding the B1359 DTC Code

The B1359 DTC code relates to a specific fault detected in the ignition key-in circuit. It commonly occurs in vehicles equipped with key-in switches as a safety measure. The purpose of this code is to alert the vehicle’s onboard computer system about any abnormality or malfunction in the key-in circuit. When this code is triggered, it typically indicates an issue with the ignition switch circuit, such as incorrect voltage or an open/short circuit.

Causes of the B1359 DTC Code

Several factors can contribute to the appearance of the B1359 DTC code. Here are some of the common causes:

  1. Faulty Ignition Switch: A malfunctioning ignition switch is a primary cause of the B1359 DTC code. The switch may fail due to wear and tear, electrical faults, or other internal issues.

  2. Wiring Issues: Faulty wiring or loose connections in the key-in circuit can trigger the B1359 code. Damaged wires, corroded connectors, or poor electrical connections can lead to an abnormal voltage supply to the vehicle’s computer system.

  3. Faulty Key-in Switch: The key-in switch itself may be defective. When the switch fails to send the correct signal to the computer system, it can trigger the B1359 DTC code.

  4. Faulty Key: In some cases, a faulty key may cause the B1359 code to appear. A damaged or worn-out key might not provide the necessary signal to the ignition switch, leading to a malfunction.

Symptoms of the B1359 DTC Code

When the B1359 DTC code is triggered, a vehicle may exhibit various symptoms indicating the underlying issue. These symptoms may include:

  • Illumination of the ‘Check Engine’ light on the instrument panel.
  • Inability to start the vehicle or intermittent starting problems.
  • An unexpected shutdown of the engine during operation.
  • Reduced engine performance or misfiring.

Diagnosing the B1359 DTC Code

To diagnose the B1359 DTC code, a mechanic or car owner can follow these steps:

  1. OBD-II Scanner: Connect an OBD-II scanner to the vehicle’s diagnostic port and retrieve the fault codes. The B1359 code will be logged in the scanner’s memory if it exists.

  2. Visual Inspection: Perform a visual inspection of the key-in switch circuit, looking for any obvious wiring issues such as damaged wires or loose connectors.

  3. Check Ignition Switch: Test the ignition switch for proper functionality using a multimeter or specialized diagnostic equipment. Ensure that the switch is operating correctly and providing the correct voltage to the key-in circuit.

  4. Check Key-in Switch: Verify the integrity of the key-in switch by conducting tests to determine if it is sending the appropriate signal to the computer system when the key is inserted or removed.

Resolving the B1359 DTC Code

Once the root cause of the B1359 DTC code has been identified, appropriate measures can be taken to address and resolve the issue. Potential solutions may include:

  1. Replacing the Ignition Switch: If the ignition switch is deemed faulty, replacing it with a new one is the most effective solution. Ensure that the replacement switch is compatible with the vehicle’s make and model.

  2. Repairing or Replacing Wiring: In cases where faulty wiring or loose connections are the cause, repair or replace the damaged wiring or connectors as necessary. Ensure the connections are tight and well-insulated.

  3. Replacing the Key-in Switch: If the key-in switch is diagnosed as faulty, it may need to be replaced. A new key-in switch should be sourced from a reputable dealer or manufacturer.

Frequently Asked Questions (FAQs) about the B1359 DTC Code

1. Can I drive my vehicle with the B1359 DTC code?

It is generally not recommended to drive a vehicle with an active DTC code, including the B1359 code. The underlying issue may worsen and potentially lead to more significant problems if not addressed promptly. It is advisable to have the vehicle inspected and repaired by a qualified mechanic before resuming regular driving.

2. How much does it cost to fix the B1359 DTC code?

The cost to repair the B1359 DTC code can vary depending on factors such as the specific cause, the make and model of the vehicle, and labor costs in your region. It is best to consult with a reputable mechanic or automotive service center to get an accurate estimate after diagnosing the issue.

3. Can I reset the B1359 DTC code myself?

While it is possible to reset the DTC codes using an OBD-II scanner, simply resetting the code will not fix the underlying problem. It is crucial to identify and address the root cause before attempting any code resets. Resetting the code without resolving the underlying issue may lead to the return of the B1359 code or other related codes.

In conclusion, the B1359 DTC code is a diagnostic trouble code commonly encountered in vehicles’ ignition key-in circuits. Understanding the causes, symptoms, and diagnostic process for this code is essential for proper diagnosis and resolution. If you come across the B1359 code, it is recommended to seek professional assistance to accurately diagnose and resolve the issue, ensuring optimal vehicle performance and safety.

About author


Meet Sam Mitchell, your experienced and reliable guide in the complex world of car fault codes. With a robust career spanning over 15 years as a professional car mechanic, John has the skills, knowledge, and practical experience to help you navigate car fault issues with confidence.


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