Live data

The Live tab shows what your engine is doing right now. A stored code tells you what went wrong once. Live data tells you what is happening while you watch, which is how you catch a fault that has not stored a code yet.

The gauge groups

Along the top is a row of tabs, each a set of readings that belong together.

Drive is the everyday set: engine speed, vehicle speed, throttle position, coolant temperature and module voltage, plus oil temperature where the car reports it.

Fuel & Air is the mixture: engine load, mass air flow, manifold pressure and the short and long term fuel trims for each bank. This is the group to be in when chasing a lean or rich code like P0171.

Timing & Load is engine speed, calculated load, timing advance, absolute load and relative throttle position.

Climate & Trip is intake air temperature, ambient temperature, barometric pressure, fuel level and run time.

Custom is up to four readings you pick yourself. Because it polls only those four, they update noticeably faster than a full group does, which makes it the right place to watch one thing closely. Tap Choose gauges to build it.

Three ways to see it

One button cycles the view.

Gauge view is dials, which is easiest to read at a glance.

List view is numbers in rows, which fits more on screen.

Graph view plots each reading over time, which is what you want for anything that moves: watching a fuel trim swing as you raise the revs tells you far more than a single number does.

All PIDs

Every group above is a curated subset. Tap All PIDs to see every reading your particular vehicle actually publishes, which on a modern car is dozens of them. There is a search box at the top for name or number, and each row shows how recently it updated.

Tap any row to open it on its own.

Looking at one reading closely

The single reading screen polls that one value as fast as your adapter will answer, charts it, and tracks the minimum and maximum for the session. Underneath it explains what the reading is, what normal looks like, and what it means when it is off.

This is the screen for diagnosing something specific. Everything else is for looking around.

Why it pauses when you switch tabs

Live polling stops when you leave the Live tab, and picks up again when you come back. That is deliberate, not a bug: continuous polling while you read a code page would slow both screens down and drain your battery for readings nobody is looking at.

The app says so on screen the first time.

Why one gauge shows two dashes

Because your car does not report that sensor.

Every vehicle publishes a different subset of the standard readings, and the list a car advertises is often longer than the list it will actually answer. The app keeps asking anyway, at no cost to the rest of the screen, so the reading appears the moment your car starts answering. On a hybrid, for instance, several engine readings fill in only when the petrol engine restarts.

A permanently blank gauge is a car that does not have that sensor. It is not a fault and there is nothing to fix.

If readings update slowly

How fast the numbers move is a property of your adapter and of how many modules the app has to wait on. Some vehicles have several modules that answer slowly, and every reading in a group waits its turn.

Two things speed it up. Use the Custom group with only the readings you care about, or open a single reading on its own screen, which polls at the maximum rate the link allows.

You can see what the link is actually doing: press and hold the Live title to open Connection health, which reports what the adapter supports and how the connection is performing.

What to do next

Chapter ten covers the three purpose-built checks that use live data to answer a specific question.