What the lateral G channel is for
Lateral G is sideways acceleration: how hard the car is being pushed toward the outside of a corner. Logged alongside RPM, throttle, speed and steering, it shows exactly where a driver is committing, where the car is running out of grip and whether a setup change helped. Its sibling, the longitudinal G sensor, measures acceleration and braking along the length of the car, and the two are usually installed together.
Setting it up in ESP comes down to three things: telling the ECU which input the sensor is wired to, loading a calibration so the voltage reads as G, and optionally setting fault limits.
Wiring tab
Under Connections, choose the input the sensor is wired to. ESP accepts either an AVI (analog voltage input) or an SPI (synchronized pulsed input). Most G sensors put out an analog voltage, so an AVI is the normal choice.
ESP presents the same connection options it uses for switch-type inputs, so you'll see these fields depending on the input type:
If you use an SPI
- Edge Select: Falling when the signal is pulled to ground to activate, Rising when it's driven up to a voltage to activate.
- Sensor Type: Hall Effect for switch-style signals.
- Pullup: turn it on if the signal needs a pull-up to produce a voltage in its off state.
If you use an AVI
For switch-style operation, the AVI needs a Switch On Voltage and a Switch Off Voltage. Leave a gap between them so small voltage wobbles can't make the state flicker. For example, if a signal sits near 0V when off and near 5V when on, setting On at 4.0V and Off at 1.0V gives plenty of margin both ways. For a proportional G signal, the calibration is what really matters, covered next.
Calibration tab
The calibration converts the sensor's voltage into G. ESP ships with a set of pre-installed calibrations. Use the yellow folder icon at the top left to load one, and the blue disk icon beside it to save your own.
If your sensor isn't in the list, build a custom calibration from the manufacturer's data sheet: the output voltage at zero G and how many volts it moves per G, over the sensor's range. Two quick checks once it's loaded:
- With the car parked on level ground, the channel should read very close to zero.
- Turn a steady circle in a parking lot one way and then the other. The reading should be similar in size and opposite in sign. If left and right look backward, the sensor is mounted reversed or the calibration slope is inverted.
Diagnostics tab
Two optional limits let the ECU flag a wiring fault. Both are disabled by default.
| Setting | What it does | Our advice |
|---|---|---|
| Raw Min | Sets code C1034 when the voltage drops below your limit, catching a short to ground or open circuit | Enable it, just below the lowest voltage the sensor produces in real use |
| Raw Max | Sets code C1035 when the voltage rises above your limit, catching a short to supply | Enable it, just above the highest voltage the sensor produces in real use |
If the Engine Protection function is active, you can also give each code a DTC severity. For a logging-only sensor like this we usually leave severity low, since a failed G sensor shouldn't stop the engine.
G-Force Filter Scale
You'll find this table under ECU Navigator > Sensor Properties > G-Force Filter Scale. It sets how much smoothing is applied to the G signal, and it's shared by the lateral and longitudinal sensors when both are set up. Chassis vibration and engine shake add a lot of fast noise to an accelerometer. A bit of filtering turns that into a readable trace. Too much makes the reading slow, so real transitions like turn-in look softer and later than they are. Start with light filtering, log a lap and add more only if the trace is hard to read.
Mounting tips
- Mount the sensor rigidly to the chassis, as close to the car's center of gravity as practical, and square to the direction of travel.
- Keep it away from the engine and exhaust, and off flexible panels that buzz.
- Route the signal wire away from ignition leads and injector wiring to keep noise down.
Troubleshooting
| Symptom | Usually |
|---|---|
| Reads a steady offset when parked | Sensor not level, or wrong zero point in the calibration |
| Signs reversed left to right | Sensor mounted backward, or calibration slope inverted |
| Very noisy trace | Soft mounting, poor wire routing, or not enough filtering |
| C1034 or C1035 logged | Open circuit, short, or a limit set inside the normal range |
G sensors are a natural fit with vehicle dynamics logging and tools like torque management. If you're setting up a data package for a track car, book a free consultation and we'll help you choose the channels that matter.
