U0167 indicates that the vehicle’s powertrain control module (PCM) has lost communication with the immobilizer control module over the CAN bus. The code is set when the PCM cannot receive expected messages from the immobilizer module for a defined period.
Open circuits, shorted wires, or oxidized connector pins prevent the immobilizer module from transmitting or receiving CAN messages.
The module’s transceiver or processor may have failed, causing it to stop communicating on the bus.
Missing or faulty termination resistors, a shorted bus line, or another node pulling the bus low can disrupt communication for all modules.
Insufficient voltage, a blown fuse, or a poor ground connection can cause the module to go offline.
A fault in the PCM’s CAN transmitter/receiver circuitry can prevent it from receiving immobilizer messages, though this is less common.
An incomplete or incorrect immobilizer software load can stop the module from participating in CAN communication.
Not usually. The code points to a loss of communication with the immobilizer module; the most common causes are wiring, connector, or immobilizer module faults. PCM failure is a rare cause and should be considered only after other possibilities are eliminated.
Low system voltage can cause temporary CAN communication loss, but the code typically sets only after voltage returns to normal and the communication fault persists.
Yes. After any immobilizer module replacement or wiring repair that affects the immobilizer circuit, the keys usually need to be relearned or the immobilizer system re‑initialized using a scan tool.
Aftermarket devices that tap into the CAN bus or the immobilizer wiring can introduce bus loading or wiring faults that lead to communication loss and set this code.