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. A dead 12V battery produces the same symptoms and is by far the more common cause, so the 12V system is checked first; the owner-reported CGM failures are rare and were identified only after jumping and replacing the 12V batteries did not revive the truck. The distinguishing signature is that the truck stays dead despite a healthy high-voltage state of charge and despite fresh 12V batteries. A related module failure with overlapping symptoms is the telematics module, and Rivian ran a separate service campaign covering some 2022 R1T trucks for incorrectly assembled Body Control Modules. 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 (3)
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.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.