U0088 code meaning
Vehicle Communication Bus F (-) Shorted to Bus F (+)
What U0088 means
With U0088 the two conductors of Vehicle Communication Bus F are bridged to each other. Signalling on both FlexRay and CAN rests on the difference between the wires, so with them joined there is none: a FlexRay receiver such as NXP's TJA1081B sees a difference below its activity threshold and treats the line as idle, while every sending node reads back something other than what it transmits and sets its bus error flag. On a single channel this ends all exchange on Bus F, which is why modules elsewhere then log the silent partners as lost. Volvo names a short between CAN-High and CAN-Low as one cause of U008088 on its truck datalink 7. For CAN, onsemi's bench tests likewise show a bridged pair stopping all traffic. Isolate sections by unplugging connectors while measuring between the wires.
U0088 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 6 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0088
- Complete loss of the functions served by Bus F
- Lost-communication codes for several modules
Common causes of U0088
- Most likelyBus F pair crushed so both wires touch
- PossibleWater or corrosion bridging both wires in a splice or connector
- Less likelyTransceiver with an internal short between 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 f wiringModule connector
What each part of U0088 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 88 | The exact fault in that area. |
What to do next
- Note U0088 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 U0088
What does U0088 mean?
U0088 means "Vehicle Communication Bus F (-) Shorted to Bus F (+)". With U0088 the two conductors of Vehicle Communication Bus F are bridged to each other. It is a generic code, so it means the same on every make.
Is it safe to drive with U0088?
Drive gently and only to a workshop. With U0088 the car can go into limp mode (reduced power) to protect itself.
Will U0088 fail an emissions test?
U0088 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 U0088 to fix?
Difficulty: hard. A typical repair takes 1 to 6 hours of work. This is a job for a workshop.
Will U0088 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.