U0007 code meaning
High Speed CAN Communication Bus (-) Low
What U0007 means
U0007 reports that the (-) line CAN-Low on the fast bus is held below its valid band, normally by a short to ground. The physical layer copes with this particular case: onsemi recorded ongoing transmission with a distorted level pattern and raised transceiver current, and NXP counts it among the hidden failures. Traffic therefore continues, yet the reserve against interference shrinks, which may surface as an occasional lost frame or a brief warning. Only modules whose transceiver offers bus diagnosis can spot the condition directly. No manufacturer documents U0007 publicly; FCA field cases describe ground shorts on the CAN C (+) and (-) lines under U0001. Inspect sections near sheet-metal edges, brackets and seat rails, then measure CAN-Low to ground with the battery disconnected.
U0007 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyHard
- Typical labor1 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0007
- Usually no noticeable malfunction, code found during a scan
- Occasional short-lived warnings, worse with moisture
Common causes of U0007
- Most likelyCAN-Low insulation worn through against body metal
- PossibleWater in a connector bridging CAN-Low to a ground pin
- Less likelyModule transceiver internally shorted on its CAN-Low pin
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
CAN low wireCAN transceiver
What each part of U0007 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 07 | The exact fault in that area. |
What to do next
- Note U0007 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 U0007
What does U0007 mean?
U0007 means "High Speed CAN Communication Bus (-) Low". U0007 reports that the (-) line CAN-Low on the fast bus is held below its valid band, normally by a short to ground. It is a generic code, so it means the same on every make.
Is it safe to drive with U0007?
U0007 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U0007 fail an emissions test?
U0007 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 U0007 to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will U0007 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.