User Manual

Power

PEAK Gauge comes in two versions: the Battery version, with a built-in battery, and the Plug-in version, which runs from USB power.

Turn on — press PWR.

Turn off — hold PWR for three seconds. If the screen is frozen, keep holding.

Auto power-off — PEAK Gauge turns itself off shortly after you switch off the engine. The Battery version stays on while it's plugged in. If the Plug-in version's USB port stays powered with the engine off, press PWR to turn it back on next time.

Low power mode — when the Battery version drops below 20%, the screen dims, readings update a little less often and LOW POWER shows beside the battery level. It ends at 25%, or as soon as you plug it in.

Screen orientation — at power-on the screen turns upright however the gauge is mounted. After moving it, turn it off and on again.

Connecting to your car

1. Plug an ELM327-compatible Bluetooth Low Energy (BLE) adapter into your car's OBD-II port.
2. Switch the ignition on.
3. Power on PEAK Gauge and pick your adapter.

The gauge remembers your adapter and reconnects to it by itself. To use a different one, tap DISCONNECT in System Settings and pick it from the list.

On a GR Supra the gauge disconnects from the adapter a few seconds after you switch off the engine, so it doesn't set off the car's alarm when you lock it. It reconnects the next time you turn it on. Don't connect to the adapter while the car is locked: that sets the alarm off too.

The USB-C cable is only for power. PEAK Gauge talks to the adapter over Bluetooth, so no cable runs between them.

Your vehicle profile

The profile is picked from your car's VIN. To choose one yourself, use VEHICLE in System Settings.

• OBD2 Generic — the standard readings, on any car.
• BRZ/GT86/FR-S (Gen 1) — adds oil temperature, and tire pressures and temperatures, which update every few minutes and read -- for a while after you start the car.
• BRZ/GR86 (Gen 2) — adds oil temperature, tire pressures and temperatures, wheel speeds, steering angle, brake pressure and the clutch. With a full GJP IO Box fitted, also its oil, fuel and coolant pressure, oil pressure ratio, ethanol content and fuel temperature, right from the OBD-II port. A GJP Mini IO Box's oil pressure needs one of the ASC profiles below.
• Toyota GR Supra A90 — adds oil temperature and pressure, oil pressure ratio (per 1000 rpm), tire pressures and temperatures, wheel speeds, steering angle, brake pressure, transmission temperature, boost target and fuel rail pressure.
• Mazda MX-5 (2016-2023) — adds tire pressures and temperatures, steering angle and brake position. The last two come from the car's own data bus, as Steering (CAN) and Brake pos. (CAN). No oil temperature.
• Mazda MX-5 (2024+) — adds oil temperature, brake position and steering angle. Tire pressures and temperatures are tried too, but no 2024+ car has been tested: if yours doesn't answer they read --.
• BRZ/GR86 (Gen 2, ASC+DD) — reads only these, not the full standard set: RPM, speed, coolant temperature, manifold pressure, gear, tire pressures, oil temperature, fuel level, the pedals, brake pressure and steering angle. Reads oil pressure and oil pressure ratio too, with an Ansix kit or a GJP Mini IO Box fitted.
• BRZ/GR86 (Gen 2, ASC+CAN) — the same channels as ASC+DD except manifold pressure, read from the car's own data bus with any adapter. Reads oil pressure and oil pressure ratio too, with an Ansix kit or a GJP Mini IO Box fitted.

On the gen-2 BRZ/GR86 profiles, the 2016-2023 MX-5 and the GR Supra A90 the screen dims while your headlights are on.

Turning off the fake engine sound

On a gen-2 BRZ or GR86, the ASC toggle on the main page switches the synthesised engine sound; on a GR Supra the same toggle is called ASD. The setting is saved in the car, and works with any adapter.

Custom vehicle profiles

Up to five profiles of your own, for a car the gauge doesn't know or to change what it shows. You build them on your phone, in a browser.

1. On the WIFI page, turn WiFi on.
2. Join the network shown and open the Profiles address in a browser.
3. Start a profile from scratch, or duplicate a built-in one and change it.
4. Pick it in VEHICLE, under CUSTOM PROFILES. The gauge restarts to load it. Changes to the profile in use apply when you turn WiFi off.

A profile lists the gauges you want, in page order. Besides the built-in readings it can have channels of its own:

• OBD — asks the car for a value, and your equation turns the reply into a reading.
• CAN (beta) — listens for data the car sends by itself. Only some cars allow this through the OBD-II port.
• Derived — works a reading out from other channels, like a sum or a ratio.

Equations use RaceChrono's syntax. With the gauge connected to your car, Live data in the editor shows each channel's real reply while you write it.

A channel can have its own warning and alert levels. For a pressure that should warn when it falls, as oil pressure does, tick Low-side.

Export saves a profile to your phone as a file, to keep or to share. Import… opens such a file as a new profile: check it, then Save. Anything this gauge can't show is left out, and the editor says what.

Getting around

Jump home — hold BOOT for one second.

At power-up the gauge returns to the gauge page you were last on.

Gauge pages

The thin line inside a ring or under a bar, and the numbers under a reading, show the range seen since you opened the page.

Multi-gauge pages

Swipe left from the page to change its layout.

Press and hold a tile to change what it shows.

The Track page

Each tire's temperature, and the outline of its card, turns yellow at the warning level and red at the alert level. Swipe left to set those levels.

Single-gauge pages

Warning and alert levels

Temperatures, boost, RPM, and brake and coolant pressure change color as they climb; oil and fuel pressure change color as they drop:

ALERTING is off for every gauge until you turn it on. The four tire temperatures share one set of levels.

System Settings

Gauge Link: two gauges at once

Two gauges can show the same car, each with its own pages. The primary connects to the adapter; the secondary gets its readings from the primary.

In System Settings, set GAUGE MODE to PRIMARY on one unit and SECONDARY on the other, restart both, then connect the primary to your adapter as usual. SINGLE, the default, is for a gauge on its own.

Trouble codes

The codes behind your check-engine light.

Updating the firmware

You'll need a phone or laptop and the new .bin file.

1. On the WIFI page, turn WiFi on.
2. Join the network shown, open the Update address in a browser and upload the .bin file.