OBD-II trouble code
U0167: Lost Communication With Vehicle Immobilizer Control Module
Another module has stopped receiving messages from the immobilizer control module — the anti-theft unit that authorizes engine start. Can cause a no-start, since the engine will not run without valid immobilizer authorization.
Quick facts
- System
- Network
- Category
- Network Communication
- Severity
- High severity
- Drivable
- No — stop driving until repaired
- Repair cost range
- $100 – $900
- DIY difficulty
- Shop recommended
What does U0167 mean?
U0167 is a module-specific network code that sets when a control module — usually the engine controller — stops hearing from the vehicle immobilizer control module on the communication bus. The immobilizer is the anti-theft system that reads the transponder in your key or fob, confirms it is authorized for the vehicle, and then tells the engine controller it is allowed to start and run. That handshake happens over the network every time you try to start the car. When the immobilizer module's messages disappear from the bus, the engine controller can no longer confirm authorization and logs U0167.
Unlike a generic bus fault, U0167 names the missing component: the network reports that the immobilizer control module specifically has gone silent. That can happen because the module lost power or ground, because the wiring to it is damaged, because the module itself has failed, or because the immobilizer and engine controller are no longer correctly synchronized after a battery, key, or module event. It can also be a downstream symptom of a wider bus problem, in which case other U-codes are usually stored at the same time.
In practice U0167 often shows up as a no-start or a start-then-stall, frequently with a security or key warning light on the dash, because the engine controller treats lost immobilizer communication as a failed authorization. That makes this a higher-urgency code than most lost-communication faults: even though nothing is mechanically wrong with the engine, the car may not run until communication and anti-theft synchronization are restored. It should be diagnosed before driving, and many repairs in this area require dealer-level tools to re-sync or program the immobilizer.
Common causes
- Blown fuse or lost power feed to the immobilizer control module
- Poor or corroded ground at the module
- Damaged, chafed, or corroded CAN wiring between the module and the bus
- Corroded or backed-out terminals at the module connector
- Immobilizer and engine controller out of sync after a battery, key, or module change
- Internally failed immobilizer control module (or host body control module)
- A wider CAN bus fault dragging this module off the network
Symptoms
- Engine cranks but will not start, or starts then immediately stalls
- Security / anti-theft or key warning light illuminated
- Key or fob not recognized; immobilizer message on the dash
- Intermittent no-start that comes and goes with wiring movement
- Additional lost-communication U-codes if a wider bus fault is present
Diagnostic steps
- 1.Scan all modules and record every stored code; several U-codes suggest a bus-wide fault rather than just the immobilizer module.
- 2.Confirm power and ground at the immobilizer control module (or host body control module) with the key on — check the feed fuse and verify a clean, tight ground.
- 3.Inspect the module connector and harness for corrosion, water intrusion, backed-out terminals, and chafing.
- 4.Check the CAN wiring from the module to the bus for continuity and for shorts to power or ground.
- 5.Verify the immobilizer recognizes the key/transponder and that the module is still synchronized with the engine controller; a recent battery or key event can require re-learning.
- 6.If power, ground, wiring, and key recognition are good but communication is still lost, suspect an internally failed module — re-sync or replacement often needs dealer-level programming.
Repair cost
$100 – $900
Diagnosis usually runs $100-$200. A power, ground, or wiring repair is often $150-$450. Re-synchronizing or relearning the immobilizer typically requires dealer-level tools and can run $100-$300. If the immobilizer or host module is internally failed, replacement and programming can run $400-$900+ depending on the vehicle's security system.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with module communication / can bus diagnosis preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
Leave this one to a qualified shop. It typically involves emissions-critical components, refrigerant handling, or other work that requires manufacturer-grade tooling, training, or certification. DIY attempts often produce a more expensive problem than the original code.