Hi, Porsche just issued a recall on 991S for possible fuel leak that might cause engine to stall.

I wonder that if the engine stalls during driving, do the fully electronic power steering wheel and brake still work? It is good to know for my own safety, it is not specific question for Porsche car but in general since my new BMW X3 also has the same fully electronic power steering.

Your comment is greatly appreciated.

 

I would imagine quite the opposite..With hydraulic steering if the engine is not rotating neither is the steering pump (IE no power assist), and same for the vaccuum brake booster. Conversely the engine not spinning does not mean the battery dies

 

Same goes for hydraulic... no?
p.s. I didn't know 991 had electronic brake?

 

EPS works off of the alternator, not the battery. If the engine dies, then the EPS will not work.

 

I found this

Electro Hydraulic Power Steering (EHPS): This design utilises a hydraulic steering pump driven by an electric motor. The pump powers a standard hydraulic power steering rack gear.

Electric Power Assisted Steering (EPAS): This design utilises a steering column which is powered by an electric motor. This assists a standard rack and pinion unit.

Electric Power Steering (EPS): This design brings together a rack and pinion steering unit and an integrated electric motor offering power assist.

Which one Porsche is using? I believe it is EPS system?

Electric power steering (EPS or EPAS) uses an electric motor to assist the driver of a vehicle. Sensors detect the position and torque of the steering column, and a computer module applies assistive torque via the motor, which connects to either the steering gear or steering column. This allows varying amounts of assistance to be applied depending on driving conditions. Engineers can therefore tailor steering-gear response to variable-rate and variable-damping suspension systems, optimizing ride, handling, and steering for each vehicle. These give more assistance as the vehicle slows down, and less at faster speeds. In the event of component failure that fails to provide assistance, a mechanical linkage such as a rack and pinion serves as a back-up in a manner similar to that of hydraulic systems.

Electric systems have an advantage in fuel efficiency because there is no belt-driven hydraulic pump constantly running, whether assistance is required or not, and this is a major reason for their introduction. Another major advantage is the elimination of a belt-driven engine accessory, and several high-pressure hydraulic hoses between the hydraulic pump, mounted on the engine, and the steering gear, mounted on the chassis. This greatly simplifies manufacturing and maintenance. By incorporating electronic stability control electric power steering systems can instantly vary torque assist levels to aid the driver in corrective maneuvers.