I've since fully charged the battery and the car starts fine again, but the Power Steering warning persists. Best guess right now is that the one of the failed jumps dropped voltage enough that Power Steering thought I disconnected the battery, so I tried to follow the reset instructions I found at https://www.porscheclubgb.com/forum/tm.aspx?m=770011:
Steering angle sensor (PSM)
The steering angle sensor must be re-initialised when the battery is disconnected and connected.
- Turn wheels to straight-ahead position.
- Switch ignition off and then on again twice.
- Start engine.
- From the straight-ahead position, turn steering wheel approx. 20° to the right, past the straight-ahead position.
- Drive the vehicle straight ahead for at least one second at a speed above 4 km/h (2.5 mph).
- The steering angle sensor segment is recognised again in this process.
- Once the sensor has been successfully initialised, the fault code that is stored in the fault memory is documented using the fault deletion counter.
- The fault memory erases itself automatically.
- The PSM indicator light in the instrument cluster goes out.
That didn't do it although I'm not sure whether I'm supposed to "drive straight" with the wheel at 20° or straighten it again first?
Regardless, does anyone else have any troubleshooting advice or failing that any recommendations on indie shops to take it to? Recently passed the extended CPA and have not had a Porsche in SD for over 10 years, so I no longer know the local shops.
thanks,
arne