U0013 code meaning
Medium Speed CAN Communication Bus (+) Low
What U0013 means
U0013 indicates that CAN-High on the medium-speed bus, the (+) wire, is pulled toward ground. Where this network uses the same differential layout as high-speed CAN, as Saab's terminated mid-speed GMLAN suggests, a grounded CAN-High rules out any dominant bit; onsemi and NXP list this short among those that end all communication. Every node on the segment, usually body, climate and infotainment units, therefore goes quiet together, and the gateway or body controller stores missing-message codes for them. No manufacturer documents U0013 publicly. Powertrain functions on the separate fast bus normally carry on. With the battery off, a resistance of only a few ohms from CAN-High to ground locates the short; typical spots are door boots, seat rails and trim fasteners.
U0013 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor1 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0013
- All comfort and infotainment modules fail together
- Engine and transmission keep working normally
Common causes of U0013
- Most likelyMedium-speed CAN-High insulation damaged against body ground
- PossibleWires broken open in a door trunk or tailgate grommet
- Less likelyComfort module transceiver pulling CAN-High down
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
CAN high wireBody control module
What each part of U0013 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 13 | The exact fault in that area. |
What to do next
- Note U0013 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 U0013
What does U0013 mean?
U0013 means "Medium Speed CAN Communication Bus (+) Low". U0013 indicates that CAN-High on the medium-speed bus, the (+) wire, is pulled toward ground. It is a generic code, so it means the same on every make.
Is it safe to drive with U0013?
U0013 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U0013 fail an emissions test?
U0013 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 U0013 to fix?
Difficulty: medium. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will U0013 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.