High Speed CAN Communication Bus (-) Low
What it means
U0007 means the high-speed CAN bus 'minus' (CAN-Low) wire is being pulled low, typically a short to ground or a wiring fault on the bus. The high-speed CAN is the shared network the engine, transmission, ABS, and other modules use to talk. When it's disrupted, many modules can lose communication at once, producing multiple warning lights and, depending on what's affected, limp mode, stalling, or a no-start.
Can I keep driving? Maybe not — a shorted CAN line can knock multiple modules offline, causing warning lights, limp mode, or a no-start/stall depending on which systems drop out; have it diagnosed before relying on the car.
Common symptoms
What you'll notice
- Multiple warning lights on at once (ABS, traction, engine, airbag, etc.)
- No-communication faults from several modules on a scan tool
- Erratic gauges, no-start, stalling, or limp mode
- Some modules unreachable by the scan tool
Common causes
Most likely first
- CAN-Low wire shorted to ground or shorted to another circuitLikely
- Chafed, pinched, or corroded bus wiring or a damaged connectorCommon
- A failed module dragging the bus lowCommon
- Water intrusion into a connector or module on the busLess often
How to diagnose & fix
Work through it in order
- Scan all modules to map which are online and which have lost communication.
- Inspect CAN wiring and connectors for chafing, water, and shorts; measure CAN-Low for a short to ground.
- Disconnect modules one at a time to isolate a module pulling the bus low.
- Repair the shorted wiring or replace the faulty module/connector, then clear and verify all modules communicate.
FAQ
Quick answers
Is it safe to drive with U0007?+
Can I just clear U0007?+
Related codes
Often seen with U0007
Read & clear U0007 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.