Mobileye Error ER-77 — G-Sensor Failure

What it means

ER-77 on a Mobileye unit means the internal G-sensor (accelerometer) has failed or is giving readings outside the expected range.
The G-sensor measures vehicle acceleration and deceleration to help calibrate certain warning functions.
ER-77 is a hardware fault in the camera unit that typically requires replacement.

Affected Models

Mobileye 6 Series
Mobileye 8 Connect
Mobileye Shield+
Mobileye 630
Mobileye 650

Common Causes

Internal accelerometer component failure in the camera unit
Physical shock or impact to the camera unit damaging the MEMS accelerometer
Firmware issue causing the G-sensor to report invalid data

How to Fix It

Power cycle the vehicle — ignition off for 30 seconds, then restart.

A transient firmware issue may cause a false ER-77 that clears after a power cycle.
If ER-77 persists, note whether the vehicle was in a recent impact or collision.

Even a minor collision or a hard kerb strike can physically damage the MEMS accelerometer chip inside the camera unit.
Report this information to the service technician.
Contact a Mobileye authorised installer for camera unit inspection.

The technician will confirm ER-77 and arrange unit replacement if the G-sensor has genuinely failed.

When to Call a Professional

ER-77 is an internal hardware fault.
The accelerometer is built into the sealed camera unit — it cannot be replaced separately.
Contact a Mobileye authorised service partner for camera unit replacement.

Frequently Asked Questions

Does ER-77 affect the forward collision warning?

The G-sensor contributes to calibration of certain warning thresholds.
With ER-77 active, some warning functions may be reduced or disabled.
Do not rely on the Mobileye system for collision protection while ER-77 is showing.

What is a MEMS accelerometer?

MEMS stands for Micro-Electro-Mechanical Systems — it is a tiny mechanical sensor etched onto a silicon chip.
The accelerometer in Mobileye detects forward/backward and side forces on the vehicle.
MEMS devices are reliable but can be damaged by strong physical shock.