U0146 on Rivian: How to Diagnose & Fix
Lost Communication With Gateway "A"
1 Rivian model · 1 documented issue · 1 critical
U0146 on Rivian by model: symptoms, diagnosis and fix
The Central Gateway Module is the routing hub of the R1T's vehicle network: it brokers messages between the CAN/Ethernet domains, gates OTA update delivery, and manages the wake/sleep state of the rest of the modules. When the CGM fails, the truck goes fully unresponsive — it will not wake from sleep, will not respond to the key fob, phone key, or Rivian app, will not unlock, and critically will not release a plugged-in EVSE connector, which leaves the truck physically tethered to the charger. Owners frequently misdiagnose this as a 12V battery problem first, and report replacing the 12V batteries with no improvement before a technician identifies the CGM. The distinguishing signature is that the truck is dead despite a healthy state of charge (owners report this at 80 percent-plus HV charge) and despite fresh 12V batteries. Related module failures with overlapping symptoms include the telematics module, and Rivian ran a separate service campaign covering some 2022 R1T trucks built roughly August through December 2021 for incorrectly assembled Body Control Modules that could fail suddenly. This is a tow-in event, not a roadside fix.
Common Symptoms
- Vehicle completely unresponsive and will not wake from sleep
- Key fob, phone key, and Rivian app all fail to unlock the truck
- Charge cable will not release from the charge port
- Truck dead despite a high high-voltage state of charge
- No response after replacing the 12V batteries
- App shows the vehicle offline or unreachable indefinitely
How to Fix
There is no owner-side remedy — the CGM is VIN-locked and must be replaced and programmed by Rivian. Before assuming the worst, have Rivian remote diagnostics confirm whether the vehicle is reachable at all, and rule out a flat 12V system (a genuinely dead 12V presents similarly but responds to a jump at the front 12V access point). If the truck stays dead with good 12V and good HV state of charge and will not release the charge cable, expect a CGM or telematics module replacement. Use the manual charge-cable release procedure to free the EVSE so the truck can be towed. Replacement is covered under the basic vehicle warranty; out of warranty, module plus programming and diagnostic labor runs into four figures. Owners of 2022 trucks built August-December 2021 should also ask Rivian whether their VIN falls under the Body Control Module service campaign.
Sources for this issue (4)
U0146 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 U0146 mean on a Rivian?
U0146 stands for "Lost Communication With Gateway "A"." Sets when a module loses data-bus communication with Gateway 'A' (the serial-data gateway module that bridges multiple vehicle networks). Because the gateway routes traffic between bus segments, loss can cascade into many lost-communication codes. On Rivian it is documented across 1 model: R1T.
What are the most common causes of U0146?
The most common causes of U0146 are: Open, shorted, or chafed bus wiring at the gateway module, Corroded or loose gateway connectors / poor ground, Blown fuse / lost power feed to the gateway, Low battery voltage, Failed gateway module. The specific cause varies by vehicle.
How much does it cost to fix U0146 on a Rivian?
Repair costs vary widely with the root cause and Rivian model; each issue on this page carries its own estimate where one is published.
Looking for U0146 on a different make?
View U0146 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.