Customer Concern: The power steering is inoperative.
Tests: 1. At the 2-pin connector on the Electro-Hydraulic Power Steering pump unit (EHPS), check that the Red wire has constant battery voltage from fuse FL4 and that the Brown wire is a good ground.
2. At the 3-pin connector on the EHPS, the Green/White wire should have ignition-on battery voltage from fuse F39, and the Yellow wire should have battery voltage from the D+ circuit on the alternator with the engine running. The third wire, Violet/White, is the diagnostic wire from the EHPS to the car's diagnostic connector.
3. If the three power inputs and the ground are good, and the pump does not operate, it is bad and has to be replaced.
Potential Causes: Electro-Hydraulic Power Steering Pump (EHPS)
Confirmed Fix: Replaced Electro-Hydraulic Power Steering (EHPS) Pump
Tech Tips: 1. Make sure that the cooling fan for the EHPS, mounted under the pump, comes on when the radiator cooling fan does. Overheating can damage the EHPS.
2. The EHPS is a self-contained unit with its own control module that works automatically on demand as the steering wheel is turned.
3. On early production cars, up to 12/2002, there is a wiring update for the EHPS cooling fan, found under Technical Service Bulletin (TSB) # M32 03 04, that isolates the power supply of the EHPS cooling fan from that of the radiator cooling fan.