B1159 - Loss of Serial Data-Key Not Received

Introduction:

The B1159 diagnostic trouble code (DTC) signifies a communication failure within a vehicle's electronic systems, specifically indicating a "Loss of Serial Data - Key Not Received." This code generally points to a problem with the communication between the immobilizer system (which verifies the key's validity) and other modules, such as the engine control unit (ECU). Addressing this issue is crucial for restoring normal vehicle operation, as it often prevents the engine from starting.

Table: B1159 Troubleshooting and Information

Detailed Explanations

Definition:

The B1159 code indicates that the vehicle's immobilizer system is not receiving the correct data from the key's transponder, or the received data is corrupted. This communication failure prevents the vehicle from authorizing the engine to start, effectively immobilizing the vehicle. The immobilizer system is a security feature designed to prevent theft by ensuring that only authorized keys can start the engine.

Symptoms:

The most prominent symptom of a B1159 code is the inability to start the engine. The security light on the dashboard will likely be flashing, indicating that the immobilizer system is active and preventing engine operation. You may also experience a lack of key functionality, such as the remote lock/unlock buttons not working. The presence of the B1159 code itself, confirmed by a scan tool, is a key symptom.

Possible Causes (Detailed):

• Immobilizer Failure: The immobilizer module itself may have failed due to internal component damage or electrical issues. This is often the least likely cause, but it is still a possibility.
• ECU Failure: Although less common, a malfunctioning ECU can disrupt communication with the immobilizer system. Damage to the ECU's internal circuitry or corrupted software can lead to this issue.
• Wiring Harness Issues: Damaged, corroded, or shorted wiring between the immobilizer, key transponder antenna, and other modules is a frequent cause of communication problems. Look for frayed wires, loose connections, and signs of corrosion, especially in areas exposed to moisture or heat.
• Faulty Key Transponder: The transponder chip inside the key may be damaged or have lost its programming. Damage can occur from dropping the key, exposure to extreme temperatures, or simply from wear and tear.
• Key Programming Issues: The key may not be properly programmed to the vehicle's immobilizer system. This can occur after replacing a key or if the key's programming has been corrupted.
• CAN Bus Communication Problems: The Controller Area Network (CAN) bus is a communication network that allows various modules in the vehicle to communicate with each other. Problems with the CAN bus, such as a short circuit or a broken wire, can disrupt communication between the immobilizer and other modules.
• Antenna Coil Malfunction: The antenna coil, usually located around the ignition switch, is responsible for reading the transponder chip in the key. If the antenna coil is faulty, it may not be able to read the key's data, leading to a communication failure.
• Power Supply Issues: The immobilizer system requires a stable power supply to function correctly. Insufficient voltage or a fluctuating power supply can prevent the immobilizer from communicating with other modules.

Diagnostic Steps:

1. Scan for other DTCs: Use a scan tool to check for other diagnostic trouble codes that may be related to the B1159 code. Other codes can provide valuable clues about the underlying problem.
2. Inspect wiring harness and connectors: Carefully inspect the wiring harness and connectors associated with the immobilizer system, ECU, and key transponder antenna. Look for signs of damage, corrosion, or loose connections.
3. Check immobilizer power and ground: Use a multimeter to verify that the immobilizer module is receiving the correct voltage and has a good ground connection.
4. Test key transponder: Use a key programmer or diagnostic tool to test the key transponder and verify that it is transmitting a valid signal.
5. Verify key programming: Use a key programmer to verify that the key is properly programmed to the vehicle's immobilizer system. If necessary, reprogram the key.
6. Check CAN bus communication: Use a scan tool to check for CAN bus communication errors. If there are communication errors, troubleshoot the CAN bus network.
7. Test antenna coil: Use a multimeter to test the antenna coil for proper resistance and continuity. A faulty antenna coil should be replaced.
8. Consult vehicle-specific service manual: Refer to the vehicle-specific service manual for detailed information about the immobilizer system and troubleshooting procedures.
9. Test immobilizer module: If all other troubleshooting steps have failed, the immobilizer module may be faulty. Consider testing the immobilizer module with a specialized diagnostic tool or replacing it.
10. Test ECU (last resort): If all other troubleshooting steps have failed, the ECU may be faulty. This should be considered a last resort, as ECU replacement can be expensive.

Repair Strategies:

1. Repair or replace damaged wiring: Repair or replace any damaged, corroded, or shorted wiring in the immobilizer system.
2. Replace faulty key transponder: Replace the key if the transponder is faulty or damaged.
3. Reprogram keys: Reprogram the keys to the vehicle's immobilizer system if they are not properly programmed or if the programming has been corrupted.
4. Repair or replace faulty immobilizer module: Repair or replace the immobilizer module if it is faulty.
5. Repair or replace faulty ECU: Repair or replace the ECU if it is faulty, but only after exhausting other possible solutions.
6. Repair CAN bus communication issues: Troubleshoot and repair any CAN bus communication issues that may be disrupting communication between the immobilizer and other modules.
7. Replace faulty antenna coil: Replace the antenna coil if it is faulty.
8. Ensure proper power supply to the immobilizer: Verify that the immobilizer system is receiving a stable and adequate power supply.

Tools Required:

• Scan tool: To read and clear diagnostic trouble codes.
• Multimeter: To test voltage, continuity, and resistance in the wiring and components.
• Wiring diagram: To understand the wiring layout of the immobilizer system.
• Key programmer: To program or reprogram keys to the vehicle's immobilizer system.
• Test light: To check for power and ground connections.
• Socket set: To remove and install components.
• Wire strippers/crimpers: To repair or replace wiring.
• Soldering iron (optional): For making secure wiring connections.

Related DTCs:

• B1158 (Key Code Not Programmed): Indicates that the key code is not programmed into the immobilizer system.
• B1157 (Immobilizer Malfunction): Indicates a general malfunction within the immobilizer system.
• U0001 (High Speed CAN Communication Bus): Indicates a problem with the high-speed CAN communication bus.
• U0100 (Lost Communication With ECM/PCM): Indicates a loss of communication with the engine control module (ECM) or powertrain control module (PCM).
• B1000 (ECU Internal Fault): Indicates an internal fault within the ECU.

Vehicle Specifics:

The location and function of the immobilizer system can vary significantly between vehicle manufacturers and models. Some vehicles have the immobilizer integrated into the ECU, while others have a separate immobilizer module. Always consult a vehicle-specific repair manual for detailed information about the immobilizer system in your vehicle.

Severity Level:

The severity level of the B1159 code is high because it prevents the vehicle from starting. This can leave you stranded and requires immediate attention to resolve the issue.

Potential Costs:

The cost of diagnosing and repairing the B1159 code can vary depending on the cause of the problem. Diagnosis typically costs between $75 and $150. Key programming can cost between $50 and $200. Wiring repair can range from $50 to $500. Immobilizer replacement can cost between $200 and $800. ECU replacement can be the most expensive, ranging from $500 to $2000 or more.

Frequently Asked Questions:

What does the B1159 code mean? It means there's a communication problem between the immobilizer and other vehicle modules, preventing key verification.

Can I fix the B1159 code myself? Depending on your mechanical skills and the problem's complexity, you might be able to fix it. However, professional diagnosis is recommended.

Will a dead battery cause a B1159 code? A severely dead battery can sometimes corrupt the immobilizer system's memory and trigger the code.

How can I clear the B1159 code? Use a scan tool to clear the code after addressing the underlying problem. The code will return if the issue persists.

Is it safe to drive with a B1159 code? No, the vehicle won't start with this code, so driving is not possible until the problem is fixed.

Conclusion:

The B1159 code represents a significant communication failure within your vehicle's security system, preventing it from starting. Thorough diagnosis and repair, potentially involving key reprogramming, wiring repairs, or module replacement, are crucial for restoring normal vehicle operation.