B1249 Code Meaning, Causes, Symptoms, & How to Fix

The B1249 code signifies a communication interruption between the Double Lock Door Control Relay and the Main Body ECU in a vehicle.

This can lead to various symptoms, such as the inability to lock or unlock the doors remotely, malfunctioning interior lights, or issues with the central locking system.

The causes of this code may include a faulty relay, damaged wiring or connectors, or a malfunctioning Main Body ECU.

To fix the B1249 code, it is essential to diagnose the underlying problem accurately. This can be done by inspecting the relay, checking the wiring and connectors for any damage or loose connections, and testing the Main Body ECU.

Once the issue is identified, appropriate repairs or replacements can be made to restore proper communication and resolve the code.

B1249: Failure between the Double Lock Door Control

What does it mean

The B1249 code indicates a communication failure between the Double Lock Door Control Relay and the Main Body ECU. Ignoring this code can compromise the vehicle’s security and may indicate larger electrical issues.

Promptly addressing the B1249 code is crucial for proper functioning of the double lock door system and overall vehicle safety.

What are the symptoms

The B1249 code may have several symptoms that can indicate a problem with the Double Lock Door Control Relay or related issues. Here are some common signs to watch out for:

• Engine Light ON: One noticeable symptom is when the engine light or service engine soon warning light illuminates on the vehicle’s dashboard.

What are the causes

One potential reason for the B1249 code is a faulty Double Lock Door Control Relay. Common problems that can cause a lack of communication between the Double Lock Door Control Relay and Main Body ECU include:

• The wiring harness for the Double Lock Door Control Relay is open or shorted, which interrupts the flow of electrical signals.
• The Double Lock Door Control Relay circuit may have a weak electrical connection, leading to communication issues.
• The Main Body ECU itself could be defective, resulting in a loss of communication.

What Tools are Needed to diagnose

To diagnose the B1249 code, you will need a diagnostic scanner and a multimeter. There are a few challenges that you might encounter when diagnosing this code:

1. Limited access to the Double Lock Door Control Relay and Main Body ECU may make it difficult to physically inspect and test the components.
2. Poor electrical connections or damaged wiring harnesses may cause intermittent communication issues, making it challenging to pinpoint the exact cause of the code.

To troubleshoot the B1249 code effectively, follow these best practices:

1. Start by connecting the diagnostic scanner to retrieve the trouble codes and freeze frame data for further analysis.
2. Visually inspect the wiring harness and connectors for any signs of damage or corrosion.
3. Use a multimeter to check for continuity and resistance in the Double Lock Door Control Relay circuit.
4. Test the Double Lock Door Control Relay and Main Body ECU for proper functionality using the diagnostic scanner’s bi-directional control and output tests.

How to fix Step by Step

Step 1: Start by visually inspecting the wiring harness and connectors related to the DTC B1249. Look for any signs of damage, such as frayed wires or loose connections.

Step 2: Check for broken, bent, pushed out, or corroded connector pins. If any are found, repair or replace as necessary.

Step 3: Use a multimeter to test the continuity of the wiring harness. Look for any open or shorted circuits.

Step 4: Test the Double Lock Door Control Relay for proper functioning. If faulty, replace it with a new one.

Step 5: If all wiring and components check out, the issue may lie with the Main Body ECU. Consider having it professionally diagnosed and repaired.

What are the Common Diagnosis Mistakes

Common diagnosis mistakes can occur when dealing with the B1249 code. It is important to be aware of the misconceptions about this code to avoid errors.

Here are some commonly overlooked diagnostic procedures for the B1249 code:

1. Ignoring communication issues: One mistake is overlooking communication problems between the Double Lock Door Control Relay and the Main Body ECU. It is crucial to check for any faults or poor electrical connections in this communication pathway.
2. Neglecting visual inspections: Another mistake is not conducting thorough visual inspections of the related wiring harness and connectors. Damaged components, broken or corroded connector pins can often go unnoticed if not visually inspected.

What is the Repair Cost

The repair cost for the B1249 code can vary depending on factors such as location, make, model, and engine type, with labor rates typically ranging between $75 and $150 per hour.

To diagnose the DTC B1249 without a scan tool, visually inspect the wiring harness and connectors for damage, and check for damaged components.

Regular maintenance is crucial to prevent code recurrence.

Can I drive safely with this code?

Driving safely with the B1249 code is not recommended due to potential issues with the Double Lock Door Control Relay and Main Body ECU communication.

Ignoring this code can lead to door lock system malfunctions, compromising vehicle safety.

Promptly addressing the B1249 code is crucial for ensuring the safe operation of the vehicle.

Wrapping Up

The B1249 code is a diagnostic trouble code that indicates a communication issue between the Double Lock Door Control Relay and the Main Body ECU in a vehicle. This code can be caused by various factors, such as a faulty relay or a poor electrical connection.

By properly diagnosing the issue and following the appropriate steps to fix it, the B1249 code can be resolved effectively. It is important to address this code in order to ensure safe driving and prevent further damage to the vehicle.