OBD-II Diagnostic Trouble Code
U0167 — Lost Communication With Vehicle Immobilizer Control Module
U0167 sets when the engine controller or another module stops receiving messages from the vehicle immobilizer control module, which checks the key or transponder before allowing the engine to start. Without valid immobilizer messages, the engine controller may block starting or fueling.
Severity 4/5
Truck-relevant
Stop within 50 mi
Severity
Stop within 50 mi
Lost Communication With Vehicle Immobilizer Control Module
Code
U0167
Category
Network
Subsystem
Network
Truck-relevant
Yes
What this means for truckers
U0167 (Lost Communication With Vehicle Immobilizer Control Module) — immobilizer offline. May prevent starting.
Before you replace parts — try this first
U0167 on the Network system is most often low battery voltage during cranking — not a dead part. On commercial diesels especially, work these in order before spending money on parts:
- Confirm the symptoms. Match what your truck is doing to the Symptoms section below. If the code is set but the symptoms are not there, clear the code and re-test after a drive cycle — it may not return.
- Clean and dry the sensor connector. Water, road salt, or oil seeping into a connector is the #1 fake sensor failure. Disconnect, look for green corrosion or moisture, spray with electrical contact cleaner, dry, reseat. Many faults clear here for $0.
- Inspect the wiring harness. Trace the wire from the sensor toward the ECM — look for chafing against the engine block, melted insulation near the turbo or exhaust, or pinch points where a clamp has rubbed through.
- Test the sensor before swapping it. Most Common Causes (below) list the expected voltage or resistance range — a $20 multimeter saves a $300 sensor swap that does not fix the problem.
- Only then, replace the part. Use the OEM or a tier-1 aftermarket. Cheap sensors throw the same code in two weeks.
Symptoms
The engine may crank but not start, or not crank at all, and a security or key light may flash. On some trucks the engine starts and then stalls after a few seconds. Problems often get worse in cold weather or with low batteries.
Common causes
- CommonLow battery voltage during cranking ($100–$700)
- CommonFuse, power or ground fault at the immobilizer module ($50–$250)
- OccasionalLoose connector or damaged wiring at the immobilizer or ignition switch area ($150–$500)
- OccasionalFailed immobilizer module, antenna ring or key transponder ($200–$1200)
How to fix
Load-test the batteries and check cranking voltage
When to use: First step, especially for cold-start or no-start complaints
Check power, ground and network circuits at the immobilizer module
When to use: When the batteries are good
Try a spare programmed key and check the antenna ring connection
When to use: When the module communicates intermittently
Replace the immobilizer module and program keys and the engine controller pairing with the manufacturer's software
When to use: After the wiring and keys have been verified
Affects most
No specific vehicle pattern found in our complaint database. This code can appear on any vehicle that supports OBD-II diagnostics.
Related
- → Browse all DTC trouble codes
- → Decode a VIN to check codes for your truck
- → Owner-operator maintenance guides
- → U0100 — Lost Communication With ECM/PCM A
- → U0101 — Lost Communication With TCM
- → U0102 — Lost Communication With Transfer Case Control Module
- → U0103 — Lost Communication With Gear Shift Module
- → U0104 — Lost Communication With Cruise Control Module
Frequently Asked Questions
Can I drive with code U0167?
Drive with caution. U0167 is severity 4 — stop within ~50 miles. Most commercial diesel codes at this severity (turbo, fuel rail, transmission solenoid) can damage adjacent expensive components if left unrepaired. Get to a service location before highway-speed loads.
How much does it cost to fix U0167 on a commercial truck?
Total repair cost ranges $50–$1200 depending on the root cause. The cheapest fix is usually the first one listed below — Low battery voltage during cranking — which is also the most common. On commercial trucks the cost is usually higher than passenger vehicles due to part availability and shop labor rates ($120–185/hour at most truck shops, vs $90–130 at general auto shops). DIY-capable fixes (sensors, hoses, filters) are at the low end; major component replacements (turbo actuator, high-pressure fuel pump, transmission solenoid pack) are at the high end. Always diagnose with a scan tool BEFORE replacing parts — guessing wrong on a $1,500 turbo actuator when the actual issue was a $30 boost hose is a common expensive mistake.
Will U0167 fail a DOT inspection?
U0167 is generally not a direct DOT inspection fail item by itself. Inspectors focus on safety-critical systems (brakes, steering, tires, lights, hours-of-service). However, the check engine light alone can trigger additional inspection scrutiny. Best practice: fix the code and clear it before a planned inspection.
What's the difference between U0167 and related codes?
U0167 is closely related to: U0100 (Lost Communication With ECM/PCM A), U0101 (Lost Communication With TCM), U0102 (Lost Communication With Transfer Case Control Module), U0103 (Lost Communication With Gear Shift Module). These codes share the same subsystem (network) and often appear together. If you see this code, scan for the full code list — fixing the root cause usually clears multiple companion codes at once. If only U0167 is set without the companions, the issue is more isolated.
How do I prevent U0167 from coming back after a repair?
For U0167 (Lost Communication With Vehicle Immobilizer Control Module), prevention centers on the network system. Pay attention to ground connections at every PM — bad grounds are 70% of communication codes. Inspect harness routing for chafe points. Don't disconnect modules with the key on.