U0072 code meaning
Vehicle Communication Bus E (-) Shorted to Bus E (+)
What U0072 means
U0072 describes the (-) and (+) wires of Vehicle Communication Bus E touching each other. On a high-speed CAN this ends communication: with the pair bridged there is no differential voltage, onsemi found transmission impossible, and NXP's TJA1041 note lists the short with the faults its bus diagnosis cannot detect. A fault-tolerant low-speed CAN degrades more gently. NXP's TJA1055 treats the short as a dominant level that never ends, confirms it in 0.3-1.6 ms, shuts down its CAN-Low driver and falls back to working over one wire, and returns to differential mode once the short is gone and the recessive state holds for a while. No manufacturer documents U0072 publicly. Separating connectors along the bus while measuring the resistance between the wires narrows the location down.
U0072 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 U0072
- All modules on Bus E unreachable (high-speed type)
- Several warning messages, gateway reports lost communication
Common causes of U0072
- Most likelyHarness crushed so that both Bus E wires touch
- PossibleWater in a splice or connector bridging the pair
- Less likelyDamaged module input shorting its bus pins
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Bus e wiring
What each part of U0072 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 72 | The exact fault in that area. |
What to do next
- Note U0072 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 U0072
What does U0072 mean?
U0072 means "Vehicle Communication Bus E (-) Shorted to Bus E (+)". U0072 describes the (-) and (+) wires of Vehicle Communication Bus E touching each other. It is a generic code, so it means the same on every make.
Is it safe to drive with U0072?
Drive gently and only to a workshop. With U0072 the car can go into limp mode (reduced power) to protect itself.
Will U0072 fail an emissions test?
U0072 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 U0072 to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will U0072 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.