U0067: Vehicle Communication Bus E (+) Low
What to do
Expect a group of systems to have stopped or to be misbehaving. A network wire is being held down by a short to the bodywork.
One observation from you is worth more than any test, and it is easy to make: what is the car doing when it happens?
A wire that has rubbed nearly through does not short all the time — it shorts when the wiring moves. So:
- Only on rough roads?
- Only pulling away, or under hard acceleration?
- Only when a door is slammed?
Each of those points at a different part of the car, and all three are things you notice and a garage cannot. Write down what you see and give it to them — it can locate the fault to within a few centimetres.
And mention anything fitted to the car, since an added earth beside the network wires is a common cause and unplugging the device is a free test.
What this code means
The positive line of vehicle communication bus E is being held low. See U0004 for the short-to-earth argument and U0040 for why a failed module can hold a line down exactly as a damaged wire does.
One note follows from U0064's method and it is the useful one for a short that comes and goes.
A wire that is nearly through against a body panel does not short continuously. It shorts when the loom moves — over a bump, under acceleration, when a door slams, as the engine rocks on its mounts.
So the observation that identifies it is not what fails but what the vehicle was doing. "Only on rough roads", "only pulling away", "only when a door is slammed" each point at a different section of loom, and all three are things a driver notices and a workshop cannot.
And the physical test that follows is the same one: flex the harness by hand along its accessible length while the error counters are watched. A fault that responds to that has been located to within a few centimetres in minutes.
Likely causes
Start here
- Wiring shorted to ground · moderate
- Intermittent wiring fault · moderate
- Damaged data bus wiring · moderate
- Poor wiring splice in an aftermarket installation · moderate
Less common
- Another module holding the bus down · specialist
- Water ingress into connector · moderate
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about U0067.