This situation happened not on my car, but on my friend’s Porsche 911 GT3 RS 2025. The key point is that all errors appeared at the same time, not one after another. That detail is crucial for understanding what’s really going on.

Errors that appeared simultaneously

The dashboard showed the following warnings all at once: • Start/Stop Failure • Driving Light Control Fault • Rear Differential Lock Fault • Transmission Fault (Reverse Gear Not Available) • Pedestrian Protection System Fault • Engine Control Fault • ABS/PSM Failure • Chassis System Fault • Aerodynamics Fault

At first glance, this looks alarming. But when you break it down technically, the picture becomes much more logical.

What each error actually means

Start/Stop Failure This system is highly dependent on voltage and overall system health. When there’s a power or communication issue, start/stop is one of the first features to be disabled as a precaution.

Driving Light Control Fault Lighting systems are controlled by body control modules. Any instability in power supply or CAN communication can trigger this warning without an actual lighting failure.

Rear Differential Lock Fault The electronically controlled rear differential relies on data from ABS, wheel speed sensors, and the chassis control unit. If those signals are unavailable or inconsistent, the differential is automatically deactivated.

Transmission Fault (Reverse Gear Not Available) On the GT3 RS, the transmission is tightly integrated with stability and engine systems. When a systemic fault is detected, reverse gear may be temporarily locked as a safety measure.

Pedestrian Protection System Fault This system is extremely sensitive to voltage drops and communication errors. Even a brief CAN-bus interruption can cause it to throw a fault.

Engine Control Fault This does not necessarily indicate an engine problem. In many cases, it means the engine control unit is receiving invalid or missing data from other modules.

ABS/PSM Failure This is one of the most critical warnings. ABS and PSM act as central hubs for data used by the transmission, differential, chassis, and aerodynamics. A failure here often causes a cascade of secondary errors.

Chassis System Fault Suspension and damping systems depend on ABS/PSM and wheel-speed data. When that information is compromised, the chassis switches to a protective mode.

Aerodynamics Fault Active aerodynamics rely on vehicle speed, acceleration, and stability data. If those inputs are unreliable, the system disables itself immediately.

Why all errors appeared at once

For modern Porsche vehicles, this is a classic sign of a system-level electronic issue, not a simultaneous mechanical failure. The most likely causes include: • a temporary voltage drop or spike, • a fault in a central control unit, • a CAN-bus communication error, • a single sensor sending corrupted data to multiple systems, • or a software-related glitch or protective mode.

If all these systems had truly failed mechanically, the car would not have been drivable.

Why the errors can disappear all at once

This is another strong indicator of an electronic issue. Once power stabilizes, communication is restored, or the car is restarted, control units resynchronize and the vehicle exits its protective mode.

What happens next

The car will be sent to an official Porsche dealer for full diagnostics, including: • reading fault logs, • checking voltage history, • analyzing CAN-bus communication, • verifying software versions and updates, • testing sensors and control units.

Only after that can definitive conclusions be made.

Final thoughts

It looks dramatic on the dashboard, but from a technical standpoint this is almost certainly a centralized electronic fault, not “everything breaking at once.” Modern GT cars are extremely complex, and sometimes one single point of failure is enough to light up half the dashboard at the same time.