What U0155 means
CAN messages from or to the instrument cluster are missing.
How the engine computer detects it
The cluster is the user-facing interface — speedometer, tachometer, warning lamps, fuel level, odometer — so failure is immediately visible. On some cars warning lamps from other modules can no longer illuminate either.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Common causes
- Cluster unpowered or fuse blown Most likely
- Cluster internal failure (common on aged TFTs) Possible
- Gateway module routing CAN messages incorrectly Less likely
How to diagnose U0155
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: instrument cluster, can bus wiring.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Vehicles that report U0155 most
| Vehicle | Years | Reports | Share | Median miles |
|---|---|---|---|---|
| Ram 1500 | 2016–2025 | 3 | — |
Counts of owner complaints to the NHTSA that mention U0155 (26 in total), not failure rates: popular models get more complaints simply because more of them are on the road. Models with fewer than 3 complaints are left out.
Reading the code
- U
- Network
- 0
- Generic (SAE) code
- 155
- Specific fault
Questions drivers ask
Can I drive with code U0155?
It depends on which module stopped communicating. If the car drives normally, drive carefully to a shop. If the engine, transmission, brakes or steering act up, or many warning lights come on at once, stop and have it towed.
Often reported together
Codes that owners mention in the same NHTSA complaints as U0155. They can point to a shared cause, so it's worth checking them together.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.