U0155 indicates a breakdown in data communication between the vehicle's primary control module and the Instrument Panel Cluster (IPC). This network error prevents the dashboard from receiving or sending signals required for gauge operation and system monitoring. The module setting this code has lost the ability to talk to the dash cluster over the serial data bus.
A failed fuse cuts electrical supply to the cluster, preventing it from powering up to communicate on the network.
Open or shorted circuits in the data bus wires physically prevent signals from reaching the instrument panel.
Corrosion or loose pins at the IPC connector disrupt the physical link required for data transmission.
Internal circuitry within the dashboard unit itself may have failed, stopping all network communication.
Intermediate modules that route network traffic may malfunction and block communication paths.
Internal PCM failure is a rare cause for this specific code and should only be considered after all other options are exhausted.
Rarely. The PCM usually sets this code because it cannot see the cluster, not because the PCM itself has failed. Replacing the PCM is often an unnecessary expense for this specific fault.
It is not recommended. Critical data like speed and fuel level may be unavailable, and safety systems could be disabled.
Some modules require a relearn procedure or time to re-establish network handshake after power loss.
Yes, because the check engine light and monitor status rely on cluster communication, causing inspection failure.