U0167: Lost Communication With Vehicle Immobilizer Control Module

U0167 is a network fault indicating the main vehicle CAN bus or LIN bus has lost communication with the immobiliser (transponder) control module. The immobiliser system verifies that the key in the ignition matches the vehicle's stored authorisation before allowing the ECM to enable fuel injection and ignition. When the immobiliser module goes offline, the ECM can't complete that handshake -- in most vehicles this results in the engine cranking but not starting, or a no-start condition entirely.

The immobiliser module is typically integrated into the instrument cluster, the steering column module, or a standalone unit near the ignition barrel. Loss of communication most often comes from a power or ground supply fault to the module, a break or corrosion in the bus wiring connecting it to the main network, or a failed module. On older vehicles, corrosion in the transponder antenna ring (the ring around the ignition barrel that reads the key chip) can also interrupt the signal path and trigger this code even if the wiring to the module itself is intact.

Because U0167 can cause a no-start condition, diagnosis priority is first confirming the module has a good power and ground supply. Check relevant fuses and run a voltage test at the module connector before ordering parts. If the module is powered and grounded correctly, a scan tool that can read individual module statuses will confirm whether the immobiliser module is present on the bus or completely absent. Replacement immobiliser modules typically require dealer-level programming to pair with the vehicle's ECM.