C0079 indicates a malfunction in the variable effort steering (VES) system, which adjusts power steering assist based on vehicle speed. The control module has detected a circuit fault, performance issue, or communication error within the VES actuator or its control circuit.
The actuator or solenoid that modulates hydraulic pressure or electric assist can wear, stick, or develop an internal electrical fault, preventing proper pressure control.
Chafed, corroded, or loose wiring and connectors between the control module and actuator cause open/short circuits or high resistance.
The VES system relies on a valid vehicle speed input; a faulty speed sensor, wiring fault, or communication bus error can disable variable assist.
If the control module receives implausible steering angle or torque data, it may default to a fixed assist level and set the code.
Internal driver circuit or processor failure in the dedicated steering control module (or integrated body/chassis module) can cause the code, but this is less common than actuator or wiring issues.
Not necessarily. The code points to the variable effort control circuit or actuator, not the pump itself. The pump may be functioning normally while the modulation valve or solenoid fails.
Yes, but steering effort will not adjust for speed. Low-speed maneuvering may require more force, and high-speed stability may feel reduced. Repair is recommended for normal handling.
Rarely. The fault is most often the VES actuator, its wiring, or a missing speed signal. Control module failure is possible but should be the last conclusion after thorough circuit testing.
No. The code will return if the underlying circuit or component fault remains. Clearing only resets the warning lamp temporarily.