U0083 code meaning
Vehicle Communication Bus F (+) Low
What U0083 means
U0083 means the (+) line of Vehicle Communication Bus F is held too low, normally by a short to ground. On FlexRay, which Audi links to Bus F, the line is bus plus (BP). NXP builds its TJA1081B to survive such a short and lists short-circuit detection on the bus lines among its diagnostic features; with BP at ground instead of its idle level of roughly half the 5 V supply, the difference to BM no longer swings the way the receivers expect. If Bus F is a CAN, a grounded CAN-High stops dominant bits, which onsemi found blocks the bus. Among Volvo's typical triggers for the truck code U008088 is CAN-High grounded. No manufacturer documents U0083 itself. With the battery disconnected, measure the (+) wire to chassis.
U0083 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0083
- Several functions on Bus F fail at once
- Many lost-communication codes in other modules
Common causes of U0083
- Most likely(+) wire of Bus F chafed through to body metal
- PossibleHarness pinched by a trim panel or bracket
- Less likelyFaulty transceiver pulling the (+) line to ground
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Bus f wiringCAN transceiver
What each part of U0083 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 83 | The exact fault in that area. |
What to do next
- Note U0083 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 U0083
What does U0083 mean?
U0083 means "Vehicle Communication Bus F (+) Low". U0083 means the (+) line of Vehicle Communication Bus F is held too low, 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 U0083?
Drive gently and only to a workshop. With U0083 the car can go into limp mode (reduced power) to protect itself.
Will U0083 fail an emissions test?
U0083 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 U0083 to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will U0083 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.