Automobile & Light Truck Certification Test A5 BrakesPower Assist Unit Diagnosis and RepairEasy
A vehicle with an electric power steering (EPS) system has a diagnostic trouble code (DTC) indicating a 'Steering Position Sensor Circuit Malfunction'. The customer reports intermittent heavy steering and occasional loss of power assist. Which of the following is the MOST appropriate next step for the technician?
- ABleed the power steering system.
- BPerform a road test to verify the symptom.
- CInspect the steering position sensor wiring and connectors.
- DReplace the EPS control module.
Show answer & explanationAnswer & explanation
Correct answer: C. Inspect the steering position sensor wiring and connectors.
A DTC specifically for a 'Steering Position Sensor Circuit Malfunction' points directly to an issue with the sensor or its wiring. Before replacing major components, inspecting the circuit for obvious faults like loose connections or damaged wires is the logical first step.
Why the other options are wrong
- A. EPS systems are electric and do not use hydraulic fluid, so bleeding is irrelevant.
- B. A road test has already been performed by the customer, and a specific DTC points to a component, so further verification without initial inspection is inefficient.
- D. Replacing the control module before checking the circuit is premature and likely unnecessary.
EPS Sensor Circuit Malfunction
A diagnostic trouble code indicating an electrical fault within the circuit of an Electric Power Steering (EPS) system's position sensor.
- Often caused by wiring issues, loose connectors, or sensor failure.
- Leads to intermittent or complete loss of power assist.
- Requires inspection of the circuit before component replacement.
Memory trick: DTCs point to circuits; circuits mean wires and connectors first.