Diagnostic Trouble Code (DTC) U0167, which indicates “Lost Communication With Vehicle Immobilizer Control Module,” is an OBD2 trouble code commonly encountered in vehicles equipped with an immobilizer system. The immobilizer system is a security feature designed to prevent unauthorized access to the vehicle by disabling the engine’s ability to start without the correct key or key fob.
When the onboard diagnostic system detects a communication failure with the Vehicle Immobilizer Control Module (VICM), it means that the module responsible for receiving data from this module is unable to establish a connection. The VICM is a critical component of the immobilizer system, responsible for verifying the authenticity of the key or key fob and allowing the engine to start if the correct credentials are provided.
What are the Causes of U0167 Trouble Code?
Diagnostic Trouble Code (DTC) U0167 can be caused by various factors. Here are some common causes of U167 trouble code:
- Faulty Vehicle Immobilizer Control Module: The VICM itself may be malfunctioning due to internal component failures, software glitches, or electrical issues.
- Wiring or Connector Problems: Issues with the wiring harness or connectors connecting the VICM to other vehicle modules can cause communication failures. This may include broken wires, corrosion, loose connections, or pinched wires.
- Power Supply Issues: Insufficient power supply to the VICM or other related modules can lead to communication failures. Problems with battery voltage, ground connections, or blown fuses can affect module operation.
- Module Failure: Other modules within the vehicle’s network that communicate with the VICM may be faulty or experiencing internal issues. This could include the engine control module (ECM), body control module (BCM), or other security-related modules.
- Software or Firmware Problems: Outdated software or firmware in the VICM or other related modules can cause communication errors. Software glitches or compatibility issues between different modules can also lead to communication failures.
- Environmental Factors: Extreme temperatures, moisture, vibrations, or physical obstructions can affect the performance of modules and electronic components. Exposure to harsh environmental conditions can lead to module malfunction or communication errors.
- Interference from External Sources: Electromagnetic interference from nearby electronic devices or radio frequency interference from external sources can disrupt communication between modules, leading to communication errors.
- Mechanical Damage: Physical damage to the vehicle, such as collisions, impacts, or improper repairs, can damage modules, wiring, or connectors, causing communication failures.
What are the Symptoms of DTC U0167?
The symptoms of Diagnostic Trouble Code (DTC) U0167, which indicates “Lost Communication With Vehicle Immobilizer Control Module,” can vary depending on the specific vehicle and its immobilizer system. However, here are some common symptoms that drivers may experience:
- Illumination of Warning Lights:
- One of the most noticeable symptoms of DTC U0167 is the illumination of the Immobilizer warning lights or specific warning lights related to the vehicle’s security system.
- These warning lights typically indicate a problem with the immobilizer system or communication issues with the Vehicle Immobilizer Control Module.
- Engine No-Start Condition:
- One of the primary functions of the immobilizer system is to prevent the engine from starting without the correct key or key fob.
- If communication is lost with the Vehicle Immobilizer Control Module due to DTC U0167, the engine may not start even with a valid key or key fob. This could include intermittent starting issues, where the engine occasionally fails to start, or difficulty disarming the immobilizer system even with a valid key or key fob.
- In some cases, drivers may notice that attempts to disarm the immobilizer system are unsuccessful, resulting in repeated failed start attempts.
- Reduced Vehicle Security:
- Communication errors with the Vehicle Immobilizer Control Module can compromise the security of the vehicle, potentially allowing unauthorized access or theft.
It’s important to note that while these symptoms are commonly associated with DTC U0167, other factors or diagnostic trouble codes may also contribute to similar issues. Therefore, if you experience any of these symptoms or notice warning lights illuminated on your vehicle’s dashboard, it’s recommended to have the vehicle inspected by a qualified automotive technician.
How to Diagnose and fix Diagnostic Trouble Code U0167?
Diagnosing and fixing Diagnostic Trouble Code (DTC) U0167, involves specific actions to identify the root cause of the communication failure and perform the necessary repairs. Here’s a step-by-step guide to diagnose and fix this issue:
- Scan for Additional Codes:
- Begin by using a professional-grade diagnostic scan tool to retrieve the DTC U0167 from the vehicle’s onboard computer system.
- Scan for additional diagnostic trouble codes that may provide further insight into related issues or components contributing to the communication failure.
- Visual Inspection:
- Conduct a visual inspection of the wiring harness, connectors, and related components associated with the Vehicle Immobilizer Control Module (VICM).
- Look for signs of physical damage, corrosion, loose connections, or wiring harness issues that could affect communication.
- Check Power and Ground Connections:
- Verify the power and ground connections to the VICM and the associated modules.
- Ensure that battery voltage is reaching the module and that ground connections are secure and free of corrosion.
- Perform Functional Tests:
- Use the diagnostic scan tool to perform functional tests on the VICM and related immobilizer components.
- Verify that the module is receiving power, sending data signals, and functioning as expected during system tests.
- Inspect Other Modules and Systems:
- Check for communication issues with other modules and systems connected to the same network as the VICM.
- Inspect the engine control module (ECM), body control module (BCM), or other security-related modules for faults or communication errors.
- Interference and Electrical Issues:
- Check for electromagnetic interference from nearby electronic devices or radio frequency interference from external sources.
- Inspect the vehicle’s electrical system for faults or issues that could disrupt communication between modules.
- Component Replacement or Repair:
- If a fault is found with the VICM or related components, replace or repair the affected parts as necessary.
- Ensure that replacement modules are properly programmed and calibrated according to the vehicle manufacturer’s specifications.
- Clear DTC and Test Drive:
- After performing repairs or adjustments, use the diagnostic scan tool to clear the DTC U0167 from the vehicle’s computer system.
- Conduct a test drive to verify that the immobilizer system is functioning properly and that the communication issue with the VICM has been resolved.
- Recheck for DTC:
- After the test drive, rescan the vehicle’s computer system to ensure that the DTC U0167 does not return.
- If the code persists, reevaluate the diagnostic process and consider seeking assistance from a qualified automotive technician or dealership service department.
If you are not confident in diagnosing and repairing DTC U0167 yourself, it’s advisable to seek assistance from a certified automotive technician or dealership service department. These professionals have the expertise, specialized tools, and resources to accurately diagnose and fix complex communication issues in modern vehicles with immobilizer systems.