U0146: Lost communication with gateway A

What U0146 means

Modern cars have several data networks (engine, chassis, comfort, infotainment) and the gateway acts as the bridge between them, and often with the diagnostic socket too. This code means it has stopped responding. Because everything passes through it, it is normal to see many other codes and warnings at the same time.

Most common causes

• Low or flat battery, very common after the car has stood unused for a long time
• Blown gateway fuse
• Loose, corroded or damp gateway connector
• Poor ground on the gateway
• A faulty module jamming one of the networks
• Faulty gateway

Symptoms

• Many warning lights and messages at once
• Instrument cluster glitching or dead
• Reader cannot connect to some control units
• Unrelated functions stop working
• On some cars, no start

Can you drive with U0146?

With care Depending on which networks are cut off, the car may drive almost normally or show many faults. If brake, steering or engine warnings are on, do not take chances and get it to a garage promptly.

How to check it

Charge the battery or check its voltage first; the fault often clears. Then clear the codes and see which return: if they all come back, the garage will need to inspect the gateway and its connections.

How to read and clear U0146 with Final OBD

Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see U0146 with this same explanation and whether it’s confirmed, pending or permanent.

With Free you read this code with its short description for nothing, and clear it if the engine stores it over standard OBD. With Pro you get the full explanation, how the car was running when it was logged (revs, temperature, load) and clearing in every control unit.

Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before the ITV. It’s all in how to read and clear fault codes and in the ITV and OBD.

Similar codes

• U0128 Lost communication with the park brake control module
• U0131 Lost communication with the power steering control module
• U0140 Lost communication with the body control module (BCM)
• U0141 Lost communication with body control module A
• U0151 Lost communication with the restraints control module
• U0155 Lost communication with the instrument cluster
• U0164 Lost communication with the HVAC control module
• U0168 Lost communication with the vehicle security module (immobiliser)
• U0100 Lost communication with engine control module (ECM/PCM A)
• U0101 Lost communication with transmission control module (TCM)
• U0102 Lost communication with transfer case control module
• U0103 Lost communication with the gear shift module

U0146 is a generic code, so it means the same on any make, for example on BMW, Ford, Mercedes-Benz, Renault, Volkswagen, Volvo. See what Final OBD does on your car in makes and models.