U0073: Control Module Communication Bus Off
2 vehicles · 2 makes · $150-$3,500 repair
Most Reported On
U0073 is an OBD-II diagnostic trouble code meaning “Control Module Communication Bus Off.” U0073 means the vehicle's communication bus has shut down, or 'gone off,' meaning a control module detected so many errors on the network that it stopped transmitting to protect the bus. On a CAN network, repeated faulty signals cause a module to take itself offline, which can cascade into multiple warning lights and disabled features. This is a network/wiring code rather than a single failed sensor, and it usually points to a wiring short, a defective module flooding the bus, or a power/ground issue affecting communication. It often requires checking the whole bus circuit, not just one part. This code is most commonly reported on 2013-2024 Chevrolet Malibu, and 2021-2025 Cadillac Escalade ESV, with repair costs ranging from $150 to $3,500.
Common Causes
Typical Repair Cost
Based on 3 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose U0073, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Vehicles Affected (2)
FAQ
What does U0073 mean?
U0073 stands for "Control Module Communication Bus Off." U0073 means the vehicle's communication bus has shut down, or 'gone off,' meaning a control module detected so many errors on the network that it stopped transmitting to protect the bus. On a CAN network, repeated faulty signals cause a module to take itself offline, which can cascade into multiple warning lights and disabled features. This is a network/wiring code rather than a single failed sensor, and it usually points to a wiring short, a defective module flooding the bus, or a power/ground issue affecting communication. It often requires checking the whole bus circuit, not just one part.
What are the most common causes of U0073?
The most common causes of U0073 are: Short to power or ground on the CAN bus wiring, CAN high/low wires shorted together, A failing module continuously corrupting bus traffic, Corroded, loose, or damaged bus connectors, Loss of power or ground to a network module, Faulty gateway/central communication module, Improper or missing bus terminating resistor. The specific cause varies by vehicle.
How much does it cost to fix U0073?
Repair costs for U0073 range from $150 to $3,500, depending on the vehicle and root cause.
Which vehicles are affected by U0073?
Au7o has documented U0073 across 2 vehicle models from 2 manufacturers: Cadillac, Chevrolet.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.