C0559 - Variable Effort Steering

Circuit Description
The electrically erasable programmable read only memory (EEPROM) stores the electronic variable orifice (EVO)/Passlock(tm) module calibrations. The EVO/Passlock(tm) module performs internal tests on the EEPROM. The EVO/Passlock(tm) module indicates if any calibration faults (checksum errors) are current.
Conditions for Setting the DTC
A code sets when the EVO/Passlock(tm) module detects an internal calibration fault (checksum error).
Action Taken When The DTC Sets
The EVO/Passlock(tm) module will not send any current to the power steering solenoid actuator. This will cause the retraction of the power steering solenoid actuator valve, providing maximum fluid flow and full power steering assist at all times.
Conditions for Clearing the DTC
After the ignition is cycled, the properly programmed EVO/Passlock module indicates no internal calibration faults (checksum errors).
Diagnostic Aids
The EEPROM is not removable from the EVO/Passlock module. Replace the module, if service is required. Refer to Electronic Variable Orifice (EVO)/Passlock(tm) Module Replacement.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
1. This step makes sure that the Variable Effort Steering System Check is completed.
2. This step checks if the EVO/Passlock(tm) module was previously replaced.