U0155 U0xxx · Network (U) Medium severity
Lost Communication with Instrument Panel Cluster
The cluster is off-line. Besides the obvious display loss, the cluster is often the gateway between buses — its absence can silence other modules.
Severity guidance: Medium — drivability or emissions affected, book it in this week
Symptoms you will notice
- Blank or dead instrument display
- No speedometer or warnings
- Other modules unreachable
Common causes
Ordered from most to least likely — start at the top.
- 1 Cluster power or earth fault
- 2 CAN fault
- 3 Failed cluster
- 4 Software fault
How to diagnose it
Cheapest and least invasive first — most of these codes are not a parts problem.
- ✓ Check cluster fuses and earths.
- ✓ Determine whether the cluster acts as gateway on this vehicle — if so, expect wider communication loss.
- ✓ Measure CAN at the cluster connector.
- ✓ Check for software updates or a reset procedure.
Repair options
- Repair supply or earth
- Repair the CAN wiring
- Replace and configure the cluster
U0155 — frequently asked questions
Why do other modules vanish when the cluster dies? +
On many vehicles the cluster is the gateway between the body and powertrain buses.
Can I drive with a dead cluster? +
Usually yes, but you have no speed, warnings or fuel level. Repair before normal use.
Confirm the diagnosis before you buy parts
Send us the code, freeze-frame data and the vehicle — our engineers will tell you what to test first.