U0006 code meaning
High Speed CAN Communication Bus (-) Open
What U0006 means
U0006 points to an interrupted CAN-Low conductor, i.e. the (-) line on the high-speed network. That line rests near 2.5 V and sinks by about a volt whenever a dominant bit is sent. Nodes isolated by the break no longer receive a usable differential signal from the rest of the network, while the modules still joined on both wires can go on exchanging data. A line interruption is outside what common high-speed transceivers can diagnose themselves (NXP), so the code relies on module-specific checks such as missing acknowledgements. No manufacturer documents U0006 publicly. Frequent findings are a conductor fractured at a door or tailgate hinge, a backed-out terminal or a corroded splice. With the battery disconnected, a check across the two lines often shows about twice the normal 60 ohms when the break separates one of the terminators.
U0006 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 6 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0006
- Part of the modules unreachable, others still respond
- Warnings from the affected systems, sometimes only when moving doors or harness
Common causes of U0006
- Most likelyCAN-Low conductor fractured at a hinge or flex point
- PossibleCorroded splice or connector in the CAN-Low path
- PossibleCAN-Low terminal backed out after work on the harness
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
CAN low wireModule connector
What each part of U0006 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 06 | The exact fault in that area. |
What to do next
- Note U0006 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U0006
What does U0006 mean?
U0006 means "High Speed CAN Communication Bus (-) Open". U0006 points to an interrupted CAN-Low conductor, i.e. It is a generic code, so it means the same on every make.
Is it safe to drive with U0006?
Drive gently and only to a workshop. With U0006 the car can go into limp mode (reduced power) to protect itself.
Will U0006 fail an emissions test?
U0006 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is U0006 to fix?
Difficulty: hard. A typical repair takes 1 to 6 hours of work. This is a job for a workshop.
Will U0006 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.