Fault code 0778: Diagnosis/troubleshooting: Initialization

The steering angle sensor in Cayenne must be initialized after the following work is carried out:

Whenever the power supply is interrupted (level control system (NRA) indicator light on).
After all work on the running gear, the steering angle sensor must be calibrated.

NOTE: Calibration of the steering angle sensor must be performed on a measuring platform. First, the control unit (level control) must be coded successfully and the steering angle sensor must be initialized. The steering angle sensor must be calibrated after work has been carried out on the running gear in the area of the front axle.

DIAGNOSIS/TROUBLESHOOTING PROCEDURE

Work instruction			Display OK	If not OK
1	Initialize steering angle sensor	Switch on ignition. Position wheels straight ahead. From the straight-ahead position, turn the steering wheel approx. '15°' to the left and '15°' to the right (past the straight-ahead position). Drive the vehicle straight ahead at a speed of '> 4 km/h for at least 1 second'.	After successful initialization, the stored fault code is erased from the fault memory and the NRA control lamp goes out. → End	Go to Step 2
2	Check steering angle sensor calibration using 9588 Porsche System Tester II	Running gear set according to Porsche specifications. Wheels in straight-ahead position and steering wheel horizontal. Steering wheel may be turned by max. '± 2.0°' from the horizontal position for driving straight ahead.	After successful calibration, the stored fault code is erased from the fault memory. → End	Go to Step 3
3	Mechanical fault	Examine moving parts for damage and check mobility.	Go to Step 4	The steering angle sensor is integrated into the steering column switch and must be replaced along with this if its functionality is mechanically impaired. → End
4	Read out steering column switch control unit, fault memory and check circuit for short or open circuit	Implement fault restriction in accordance with 'Diagnosis/ troubleshooting' for steering column switch control unit.	If electric circuit is OK: Go to Step 5	Repair wiring harness circuit. → End
5	Check CAN drive	Implement fault restriction in accordance with 'Continue troubleshooting, refer to CHECKING INSTRUCTIONS/CAN DATA BUS '.	If CAN drive is OK: Go to Step 6	Repair wiring harness. → End
6	Replace steering angle sensor.		The steering angle sensor can only be replaced together with the steering column switch. → End	Go to Step 7
7	Replace instrument cluster		→ End