Code EO40, Open Power Steering Pressure Switch Circuit
The power steering pressure switch is incorporated as an ECM input to signal for the load created on the engine under high power steering demand periods, such as parking. Because of the load created on the system which may cause the engine to stall under such high power steering pump pressure conditions, the ECM compensates by automatically increasing the engine idle speed whenever the switch opens and a "LOW" voltage is sensed at terminal D11. This low voltage signals a high demand by the power steering system.
To set a Code EO40, the following conditions must be met: ECM sees steering voltage as "LOW" (indicating a high pressure), and vehicle speed is above a calibrated value.
- Tests the power steering pressure switch for proper operation by using the "self-diagnostics" system.
- This step determines whether the fault is in the switch or the circuit. A jumpered switch connector should normally indicate "HIGH", if the circuit is complete.
- This step checks for ignition source to the switch.
- This step checks for an open circuit or faulty ECM.
- Check for intermittent in system.