U0017 code meaning
Medium Speed CAN Communication Bus (-) High
What U0017 means
U0017 means CAN-Low on the medium-speed CAN, the (-) wire, is held too high, as a rule by contact with battery or another supply voltage. On a differential bus of the high-speed type this short is fatal for traffic: the line cannot be pulled down, no dominant bit appears, and onsemi and NXP both class it among the shorts that make transmission impossible. All body and comfort modules on the segment drop out at once, the gateway records missing messages, and functions such as climate control, locking or the radio may stop responding until the short is removed. No manufacturer documents U0017 publicly; the analogy rests on Saab's terminated two-wire mid-speed GMLAN. With ignition on, CAN-Low near battery voltage confirms the fault.
U0017 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 U0017
- All comfort and infotainment modules out at once
- Climate, locking or radio not responding
Common causes of U0017
- Most likelyMedium-speed CAN-Low chafed against a supply wire
- PossibleMoisture or bent pin linking CAN-Low to a supply contact
- Less likelyAccessory wiring connected to the comfort bus by mistake
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 U0017 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 17 | The exact fault in that area. |
What to do next
- Note U0017 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 U0017
What does U0017 mean?
U0017 means "Medium Speed CAN Communication Bus (-) High". U0017 means CAN-Low on the medium-speed CAN, the (-) wire, is held too high, as a rule by contact with battery or another supply voltage. It is a generic code, so it means the same on every make.
Is it safe to drive with U0017?
U0017 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U0017 fail an emissions test?
U0017 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 U0017 to fix?
Difficulty: medium. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will U0017 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.