EPS

Heavy steering force with the static steering/light steering force during high-speed driving

1.POWER STEERING SOLENOID VALVE SIGNAL INSPECTION 1
1. Start engine.





2. Change the vehicle speed from 0 to 100 km/h (0 to 62 MPH) slowly, and then check voltage between power steering control unit harness connector M8 and ground.
Terminal 7 - ground: The voltage has changed from approximately 4.4 - 6.6 V to approximately 2.4 - 3.6 V
OK or NG
OK >> GO TO 2.
NG >> GO TO 7.

2.POWER STEERING SOLENOID VALVE SIGNAL INSPECTION 2
1. Activate fail-safe function by running the engine speed at 1,500 rpm or higher for 10 seconds with the vehicle stopped.





2. Change the engine speed to the idling, to approximately 1,600 rpm, and to approximately 3,000 rpm slowly, and then check voltage between power steering control unit harness connector M8 and ground.
Terminal 7 - ground: The voltage has changed from approximately 5.5 V to approximately 2.1 V step-by-step.
OK or NG
OK >> GO TO 3.
NG >> GO TO 8.

3.CHECK POWER STEERING SOLENOID VALVE CONNECTOR
Turn ignition switch OFF, disconnect power steering solenoid valve harness connector, and check terminal for deformation, disconnection, looseness, etc.
OK or NG
OK >> GO TO 4.
NG >> Harness or connector open or shorted. Repair or replace any inoperative parts.

4.CHECK POWER STEERING SOLENOID VALVE POWER SUPPLY CIRCUIT








Check continuity between power steering control unit harness connector M8 and power steering solenoid valve harness connector F25 (VQ35DE), E211 (VK45DE).
OK or NG
OK >> GO TO 5.
NG >> Open or short in harness. Repair or replace any inoperative parts.

5.CHECK POWER STEERING SOLENOID VALVE GROUND CIRCUIT





Check continuity between power steering solenoid valve harness connector F25 (VQ35DE), E211 (VK45DE) and ground.
Terminal 2 - Ground: Continuity exist.
OK or NG
OK >> GO TO 6.
NG >> Open or short in harness. Repair or replace any inoperative parts.

6.CHECK POWER STEERING SOLENOID VALVE





Apply voltage power steering solenoid valve connector, and then make sure that the operating sound (clicking sound) is heard.
Terminal 1 (+) - 2 (-): Operating sound is heard.
OK or NG
OK >> Perform steering wheel turning force inspection. Refer to PS-9, "On-Vehicle Inspection and Service". Steering Wheel
NG >> Power steering solenoid valve is inoperative. Replace.

7.CHECK VEHICLE SPEED SIGNAL CIRCUIT








Change the vehicle speed, and then check voltage waveform between power steering control unit harness connector M8 and ground.
OK or NG
OK >> Power steering control unit is inoperative. Replace it.
NG >> Check the following systems and replace if necessary.
^ Harness between unified meter & A/C amp and power steering control unit.
^ Unified meter & A/C amp and vehicle speed signal circuit.

8.CHECK ENGINE SPEED SIGNAL CIRCUIT








Warm up the engine, and then check voltage waveform between power steering control unit harness connector M8 and ground when the engine speed is the idling and at approximately 2,000 rpm.
OK or NG
OK >> Power steering control unit is inoperating. Replace it.
NG >> Check the following systems and replace if malfunction is detected.
^ Harness between ECM and power steering control unit
^ ECM engine speed signal circuit. Refer to EC-733, "CONSULT-III Function". P0011 P0021