Im digging out this old thread because Im also dealing with the PS cut off issue. After investigating this closely using TechStream live data, I found a trace how this issue is caused.
As commonly known, this issue apears under high load turns especially in cars with sticky tires and aggressiv setup. So my attempt was to monitor the PS motor torque and see what happens. The motor torque in my 2013 EUspec seems to be limited to 7Nm max. Now, since this is a full electric unit, it seems the manufacturer has implemented an intensional "overload cutoff" when the steering is turned against full lock.
This can easily be tested: Start engine on a parked car, turn steering wheel untill full lock towards random direction. When reaching lock, just try to turn the steering wheel further against lock. After about 1s the PS cuts off and stays off, also with no warning sign or fault code deployed, as long as the torque to the steering wheel stays applied. When the "input force" to the steering wheel is reduced by a certain amount, the PS returns service.
Watching this via TechStream data, it can be seen that the "overload cutoff" jumps in once the 7Nm maximum is reached for more then about 1s. This is the same thing what can be observed under high load turns on sticky tires.
Unfortunately the manufacturer seems to not have implemented a steering angle limit failsafe condition. Meaning, it is kind of poor programming, since the steering lock protection feature should only work when steering angle is somewhere below 10% away from maximum value. But this fail check seems to not be implemented.
So, when high load is applied to the steering wheel at any angle and the torque limit is reached for more then 1s, the system quits service. This is kind of crazy, because it is actually dangerous, especially for non spirited drivers possiby entering such a situation unintended. It is redicioulous to just turn of PS support without notice. It would be okay to flash warning lights, to limit support to the max torque or to even slightly reduce it. But switching off intensionally without notice is just damn dump and crazy.
In my point od view this is a tremendous safety issue and should cause a major recall for all vehicles equiped with that system. I dont know If a software update of the PS ECU would be possible without extracting the circuit board, but this beeing said, it's mostly a software issue and Im still looking for a solution.
-The esiest solution would be to raise the max allowed torque. But this ofcourse would just shift the actual issue.
-Maybe this could also bei achieved by an inline resistor in the torque sensor circuit in order to reduce steering support in general. But also this would be a bandaid.
Anyway, the baseline is that someone sopisticated in reading, reverse engineering and reprogramming the PS ECU would be needed. I wasnt able to find any support of this kind yet. So now I want to try my luck here. Maybe @
geraldjust could imagine to develop a workarround? Or does someone know about another company or forum member expierienced enough to maybe deal with that issue?