Diagnostic Process

When servicing the Speed Dependent Steering Electronic Variable Orifice system (EVO), the following steps should be followed in order. Failure to follow these steps may result in the loss of important diagnostic data and may lead to difficult and time-consuming diagnostic procedures:

1. Perform a vehicle preliminary diagnostic inspection. This should include:
- Inspection of the power steering fluid reservoir for proper power steering fluid level, signs of contamination and for proper power steering fluid type.
- Inspection of the Power Steering Control Module (PSCM) and system for any wiring damage.
- Inspection of Power Steering Fluid Flow Actuator, connector and wiring.
- Inspection for poor powering steering pump performance.
- Inspection of the power steering gear for leaks malfunction or poor performance.
- Inspection of the vehicle speed system and wiring.
2. Perform the Diagnostic System Check. If any DTC's are displayed, note the last malfunction that occurred. Diagnose and repair this malfunction first.
3. If no DTC's or mechanical component malfunctions are present, or if the failure is intermittent and not reproducible, test drive the vehicle while using the automatic snapshot feature of the Scan Tool. Perform normal acceleration, stopping, and turning maneuvers. If this does not reproduce the malfunction, refer to intermittent diagnosis.
4. Once all system malfunctions have been corrected, clear the EVO DTC's and test drive the vehicle.