ER-77
Mobileye ADAS Collision Warning System
Severity: ModerateWhat Does This Error Mean?
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
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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.
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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.
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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.