U0155 on Mercedes-Benz: How to Diagnose & Fix
Lost Communication with Instrument Cluster
2 Mercedes-Benz models · 2 documented issues · 2 critical
U0155 on Mercedes-Benz by model: symptoms, diagnosis and fix
Recall 20V246 directly covers 26 model-year 2020 GLB 250 vehicles whose body seam in the wheel-well area may allow water into the front footwells. Water can damage control units, causing the instrument cluster display to fail, an engine no-start or an engine stall. The 26-vehicle population is not an owner-report count, and the recall does not establish that every water leak shares this path.
Common Symptoms
- VIN checked for recall 20V246
- front footwells inspected for water
- cluster, no-start or stall symptoms documented
How to Fix
Check the VIN for recall 20V246. An authorized Mercedes-Benz dealer will seal the affected body area, inspect the front footwells for water and complete necessary repairs if intrusion is confirmed. Do not buy body seals, control units or wiring from this page; eligibility, damage and parts are VIN-specific.
Sources for this issue (1)
The main fuse box in the X296 EQS SUV (shared across the EVA2 EQE/EQS family) was built with improperly manufactured 80-amp fuses. The fuse element can fail prematurely under normal load, cutting the low-voltage supply that the drive, restraint, and cluster systems depend on. Mercedes-Benz recalled the vehicles under NHTSA campaign 24V-115; a fire risk could not be ruled out. A follow-up campaign (25V-255) was opened after dealers installed the wrong fuse box on some vehicles during the first repair, re-creating the same failure mode.
Common Symptoms
- Sudden loss of drive power while driving
- Instrument cluster goes blank
- Airbag/restraint system warning light
- Vehicle will not enter READY mode
- Multiple simultaneous electrical warning messages
How to Fix
Have the dealer perform recall 24V-115 (main fuse box inspection/replacement) free of charge, and verify with the VIN whether the vehicle also falls under the 25V-255 re-repair campaign because an incorrect fuse box was fitted the first time. There is no owner-serviceable repair - the correct part number must be matched to the VIN and coded.
Sources for this issue (2)
U0155 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does U0155 mean on a Mercedes-Benz?
U0155 stands for "Lost Communication with Instrument Cluster." This is a network communication code meaning a control module (usually the engine or body computer) has lost communication with the instrument cluster over the vehicle's data bus. Modern vehicles share information between modules over a network (such as CAN), and the cluster both displays data and relays messages. When messages from the cluster stop arriving, this code sets. You may see warning lights, dead or erratic gauges, missing displays, or other modules acting up. It usually points to wiring, power/ground, or the cluster itself rather than the engine. On Mercedes-Benz it is documented across 2 models: GLB, EQS SUV.
What are the most common causes of U0155?
The most common causes of U0155 are: Faulty instrument cluster, Loss of power or ground to the cluster, Damaged or corroded CAN bus wiring, Loose or corroded connectors at the cluster, Blown fuse feeding the cluster, Short or open on the communication bus, A different failed module dragging down the bus. The specific cause varies by vehicle.
How much does it cost to fix U0155 on a Mercedes-Benz?
Repair costs vary widely with the root cause and Mercedes-Benz model; each issue on this page carries its own estimate where one is published.
Looking for U0155 on a different make?
View U0155 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.