U0167 is a generic OBD-II network communication diagnostic trouble code indicating that communication with the Vehicle Immobilizer Control Module has been lost. The immobilizer system is responsible for vehicle security and, depending on the vehicle, may verify the key or authorization status before the engine is allowed to start.
The exact immobilizer module name, location, communication network, wiring configuration, and starting authorization strategy vary by manufacturer, model, and model year. Some vehicles integrate immobilizer functions into the BCM, instrument cluster, keyless-entry module, steering-column module, or another control unit.
U0167 Code Details
Code: U0167
Meaning: Lost Communication With Vehicle Immobilizer Control Module
Type: Generic OBD-II Network Communication Code
Main System: Vehicle Immobilizer / Security / CAN Communication Network
What Does the Vehicle Immobilizer Control Module Do?
The Vehicle Immobilizer Control Module is part of the vehicle's anti-theft and starting-authorization system. It communicates with other electronic control units to determine whether the vehicle is authorized to start.
Depending on the vehicle, the immobilizer system may communicate with the engine or powertrain control module, body control module, instrument cluster, keyless-entry system, ignition system, or other security-related modules.
A loss of communication does not automatically prove that the immobilizer module itself has failed. A power-supply problem, poor ground, CAN wiring fault, connector problem, low battery voltage, or another module affecting the network can also cause U0167.
Immobilizer Module Abbreviations
Vehicle Immobilizer Control Module
Immobilizer System
Body Control Module
Powertrain Control Module
Engine Control Module
Passive Anti-Theft System
Controller Area Network
Diagnostic Trouble Code
Important: These abbreviations are not universal. The same immobilizer function may be integrated into another module or given a different manufacturer-specific name.
Symptoms of U0167
- Engine may crank but fail to start.
- Intermittent no-start condition.
- Security or immobilizer warning may appear.
- Immobilizer indicator may remain illuminated or flash.
- Key authorization may fail.
- Remote or keyless functions may become unavailable on some vehicles.
- Multiple communication-related trouble codes may be stored.
- Scan tool may be unable to communicate with the immobilizer-related module.
- Engine starting may become intermittent.
- Other body or security functions may be affected depending on vehicle design.
Common Causes of U0167
- Weak or discharged battery.
- Low or unstable system voltage.
- Blown fuse supplying the immobilizer system.
- Missing module power supply.
- Poor or damaged module ground.
- Open CAN High or CAN Low circuit.
- Shorted CAN communication wiring.
- Damaged or corroded electrical connector.
- Loose or damaged terminals.
- Water intrusion around the module or wiring.
- Damaged wiring near the steering column or body harness.
- Another control module interfering with CAN communication.
- Faulty immobilizer or security-related control module.
- Incorrect module configuration or programming after previous repairs.
How Serious Is U0167?
U0167 can be a serious communication fault because the immobilizer system may be involved in starting authorization. Depending on the vehicle, loss of communication may cause a no-start condition or intermittent starting problems.
The severity is therefore more significant when the code is active and accompanied by a security warning, key-authentication problem, or engine no-start condition.
Can You Drive With U0167?
If the vehicle starts and operates normally, it may remain drivable temporarily on some vehicles. However, U0167 should not be ignored because an intermittent immobilizer communication problem can develop into a no-start condition.
If the engine will not start or the security system is preventing starting, the vehicle should be diagnosed rather than repeatedly attempting to start it.
How to Diagnose U0167
1. Scan All Control Modules
Perform a complete vehicle scan and record U0167 together with all other stored communication, security, body, voltage, and powertrain codes.
Determine whether the immobilizer-related module is the only module that is offline or whether several modules are reporting communication problems.
2. Check Battery and Charging Voltage
Check battery condition and charging-system operation. Low voltage during starting can cause electronic modules to reset or temporarily disappear from the vehicle communication network.
3. Check Immobilizer System Fuses
Use the vehicle-specific fuse diagram to identify all fuses supplying the immobilizer, keyless-entry, body-control, or related security modules.
Do not simply replace a blown fuse. Determine why the fuse failed before returning the vehicle to service.
4. Test Module Power and Ground
Verify all required battery and ignition power supplies and test the module ground circuit according to manufacturer specifications.
A missing power or ground connection can make a properly functioning immobilizer module appear to be defective or offline.
5. Inspect Connectors and Wiring
Inspect the immobilizer-related module connectors for corrosion, loose terminals, bent pins, damaged locks, water contamination, and poor terminal tension.
Pay particular attention to wiring around the steering column, ignition area, body harnesses, fuse boxes, and locations where previous repairs may have disturbed the wiring.
6. Check CAN Communication Circuits
If the immobilizer module communicates through CAN, inspect CAN High and CAN Low circuits for opens, shorts, damaged insulation, corrosion, poor connections, or previous wiring repairs.
Do not assume that every vehicle uses the same CAN network or the same module connector pinout. Always use the wiring diagram for the exact vehicle.
7. Check for Another Module Affecting the Network
If several control modules report communication faults, investigate common power, ground, and CAN network circuits before replacing the immobilizer module.
A shorted or malfunctioning module elsewhere on the network can prevent multiple control units from communicating correctly.
8. Verify Key and Immobilizer Status
If the scan tool provides security or immobilizer data, check key authorization, immobilizer status, security status, and starting authorization parameters where available.
A key-related problem should not automatically be confused with a U0167 communication problem. The immobilizer module must first be able to communicate correctly before its authorization data can be evaluated reliably.
9. Test the Immobilizer Control Module
If power, ground, connectors, and communication circuits are confirmed to be correct, follow the manufacturer's diagnostic procedure to determine whether the immobilizer control module has an internal failure.
U0167 Oscilloscope Signal Patterns
An oscilloscope can be useful when U0167 is caused by intermittent or distorted CAN communication. The following simplified waveform cards illustrate general network conditions.
Normal / Active
Normal: Stable CAN communication activity with consistent signal transitions.
Abnormal / Distorted
Abnormal: Noise, distortion, irregular transitions, or intermittent communication activity.
Inactive / No Communication
Inactive: Expected communication activity is absent at the tested network point.
Important: These are simplified diagnostic illustrations, not manufacturer-specific waveform specifications. Actual CAN High and CAN Low voltage levels, timing, termination, and waveform characteristics must be compared with the specifications for the exact vehicle.
U0167 Diagnostic Signal Flow
↓
Immobilizer / Security System
↓
Vehicle Immobilizer Control Module
↓
CAN Communication Network
↓
BCM / ECM / PCM / Instrument Cluster
↓
Starting Authorization
U0167 OBD Live Data
Available parameters depend on the vehicle and scan tool. Where supported, useful data may include immobilizer communication status, key authorization status, security status, system voltage, starting authorization, module status, and related network information.
Live data should be combined with direct electrical testing because intermittent CAN faults, connector problems, and voltage drops may not remain present during a stationary scan.
OEM Notes for U0167
Although U0167 has a standardized generic description, the actual immobilizer architecture can vary significantly between manufacturers.
The immobilizer function may be integrated with the PATS system or another vehicle security module depending on the vehicle.
Security and immobilizer functions may involve the BCM, theft-deterrent system, ECM, or related modules depending on model and year.
The immobilizer/keyless operation system may communicate with the ECM through the CAN network. Manufacturer diagnostic procedures should be followed before replacing a module.
Security functions may involve the wireless ignition, keyless-entry, body-control, or intrusion-related systems depending on vehicle architecture.
The immobilizer function may be integrated into the BCM, instrument cluster, steering-column electronics, keyless system, or a dedicated module.
OEM warning: These examples are architectural guidance, not a substitute for the wiring diagram or factory service information for a specific vehicle. The exact module name and U0167 diagnostic procedure can vary by model year and market.
Common Repairs for U0167
- Repair missing immobilizer module power supply.
- Repair poor or damaged module ground.
- Replace a failed fuse after identifying the cause.
- Repair damaged CAN High or CAN Low wiring.
- Repair loose or corroded electrical connectors.
- Repair damaged wiring or terminals.
- Correct water intrusion.
- Repair another module that is disrupting CAN communication.
- Repair or replace the immobilizer control module when internal failure is confirmed.
- Perform required programming, coding, configuration, or initialization after module replacement.
- Perform required key or immobilizer relearn procedures according to manufacturer instructions.
U0167 Repair Cost
- Electrical/network diagnosis: approximately $100–$250+.
- Fuse or wiring repair: approximately $75–$300+.
- Connector or terminal repair: approximately $80–$250+.
- CAN network repair: approximately $100–$400+.
- Immobilizer module repair: approximately $150–$600+.
- Module replacement and programming: approximately $400–$1,500+ depending on the vehicle.
These are general estimates only. Actual costs vary according to vehicle, immobilizer design, parts availability, labor rates, programming requirements, and key-relearn procedures.
Common Repair Mistakes
- Replacing the immobilizer module before checking power and ground.
- Ignoring low battery voltage.
- Replacing a module without testing CAN communication.
- Failing to inspect connectors and terminals.
- Assuming U0167 automatically means the immobilizer module is defective.
- Ignoring other communication codes stored in other modules.
- Failing to check whether another module is disrupting the CAN network.
- Replacing a security module without checking programming requirements.
- Failing to perform the required key or immobilizer initialization procedure.
Related OBD-II Codes
- U0100 – Lost Communication With ECM/PCM.
- U0140 – Lost Communication With Body Control Module.
- U0155 – Lost Communication With Instrument Panel Cluster (IPC).
- U0164 – Lost Communication With HVAC Control Module.
- U0165 – Lost Communication With Auxiliary Heater Control Module.
- U0166 – Lost Communication With Auxiliary Heater Control Module.
- U0168 – Lost Communication With Vehicle Security Control Module.
Related U-codes should always be interpreted together with the vehicle's complete scan results. Multiple communication codes may indicate a common power, ground, CAN network, or gateway problem rather than several failed modules.
FAQ About U0167
What does U0167 mean?
U0167 means Lost Communication With Vehicle Immobilizer Control Module. It indicates that the vehicle network has lost expected communication with the immobilizer-related control unit.
Can U0167 cause a no-start condition?
Yes. Depending on the vehicle architecture, loss of communication with the immobilizer system can prevent the engine control system from receiving the required starting authorization.
Can a weak battery cause U0167?
Yes. Low or unstable system voltage can cause control modules to reset or temporarily stop communicating. Battery voltage should therefore be checked early in the diagnosis.
Can a CAN wiring problem cause U0167?
Yes. An open, shorted, damaged, or poorly connected CAN circuit can prevent the immobilizer module from communicating with other control modules.
Does U0167 mean the immobilizer module is bad?
No. Power, ground, fuses, connectors, CAN wiring, and other network modules should be tested before condemning the immobilizer control module.
Can an oscilloscope help diagnose U0167?
Yes. An oscilloscope can help identify abnormal CAN activity, electrical noise, distortion, intermittent communication, or loss of network activity when conventional electrical tests do not reveal the problem.
Does replacing an immobilizer module require programming?
Often, security-related modules require programming, coding, configuration, initialization, or key synchronization after replacement. The exact procedure is manufacturer-specific.
Can another module cause U0167?
Yes. A defective module or shorted communication circuit elsewhere on the vehicle network can interfere with communication and cause multiple control units to report U-codes.
Final Takeaway
U0167 is a generic OBD-II network communication code indicating Lost Communication With the Vehicle Immobilizer Control Module.
Because the immobilizer system can be involved in vehicle starting authorization, U0167 deserves careful diagnosis, particularly when accompanied by a security warning or no-start condition.
The most reliable diagnostic approach starts with battery voltage, fuses, module power and ground, connectors, CAN communication circuits, and a complete scan of all control modules. Do not replace the immobilizer module simply because U0167 is stored.
The exact immobilizer architecture, module name, wiring, CAN network, key authorization strategy, and programming requirements are manufacturer-specific. Always use the correct OEM service information for the exact vehicle before replacing or programming security-related components.