Power Steering: Overview Lexus SC II рестайлинг

SYSTEM DESCRIPTION

1. SYSTEM FUNCTION Progressive Power Steering (PPS) is a vehicle speed sensing type of power steering, which increases / decreases steering support in accordance with vehicle speed. The skid control ECU sends a control signal to the steering gear (PPS solenoid valve) based on a vehicle speed signal. As a result, the steering feels tighter when driving at high speeds.
2. FUNCTION OF MAIN COMPONENTS COMPONENT FUNCTION CHART Item Function Skid control ECU Skid control ECU receives vehicle speed signal from combination meter. It then sends signal to power steering solenoid valve. Power steering solenoid valve Power steering solenoid valve controls power steering fluid pressure after receiving signal from skid control ECU

DESCRIPTION

DTC DESCRIPTION REFERENCE

PS Solenoid Malfunction - Wiring Diagram. Scheme 1

Scheme 2

Scheme 3

1. PERFORM ACTIVE TEST BY INTELLIGENT TESTER (POWER STEERING SOLENOID VALVE) Select the ACTIVE TEST, use the intelligent tester (with CAN VIM) to generate a control command, and then check that the power steering solenoid valve operates. Skid control ECU ACTIVE TEST REFERENCE Item Test Details Diagnostic Note PPS solenoid Power steering solenoid valve ON / OFF - OK: Steering becomes tight. OK: REPLACE SKID CONTROL ECU NG: Go to Next step
2. INSPECT POWER STEERING SOLENOID VALVE Check the resistance of the solenoid. Remove the solenoid valve. Measure the resistance of the solenoid valve. Standard resistance RESISTANCE REFERENCE Tester Connection Specified Condition 1 - 4 6 to 11 ohms Check the operation of the solenoid. Apply battery voltage to the solenoid valve connector and check operation of the power steering solenoid valve. (Scheme 2): Identifying Solenoid Valve Connector Terminals OK VOLTAGE SPECIFICATION Tester Connection Specified Condition Battery positive (+) --> Terminal 1 Battery negative (-) --> Terminal 2 Solenoid valve makes a click sound NOTE: Do not apply voltage for more than 30 seconds to avoid burnout of the solenoid. When performing this step continuously, wait until the solenoid cools down enough so that it can be touched by hand. NG: REPLACE POWER STEERING SOLENOID VALVE OK: Go to Next step
3. CHECK WIRE HARNESS (SKID CONTROL ECU - POWER STEERING SOLENOID VALVE) Disconnect the S5 ECU connector. Disconnect the P2 valve connector. (Scheme 3): Identifying S5 ECU Connector Terminal And P2 Valve Connector Terminal Measure the resistance of the wire harness side connectors. Standard resistance RESISTANCE REFERENCE Tester Connection Specified Condition S5-14 (SOL+) - P2-1 Below 1 ohms S5-21 (SOL-) - P2-2 Below 1 ohms NG: REPAIR OR REPLACE HARNESS AND CONNECTOR OK: REPLACE SKID CONTROL ECU

Identifying Vane Pump Components With Torque Specifications (1 Of 3). Scheme 4

Identifying Vane Pump Components With Torque Specifications (2 Of 3). Scheme 5

Identifying Vane Pump Components With Torque Specification (3 Of 3). Scheme 6

Scheme 7

1. DRAIN POWER STEERING FLUID
2. REMOVE ENGINE UNDER COVER Remove the 16 screws and under cover.
3. REMOVE ENGINE UNDER COVER REAR RH Remove the 2 bolts and under cover.
4. REMOVE NO. 1 AIR CLEANER INLET Remove the bolt and No. 1 air cleaner inlet.
5. REMOVE AIR CLEANER ASSEMBLY Disconnect the MAF meter connector. Remove the clamp. Remove the 3 bolts and air cleaner.
6. REMOVE FAN AND GENERATOR V BELT Set a wrench on the drive belt tensioner set bolt. Turn the drive belt tensioner set bolt counterclockwise and hold it. HINT: The drive belt tensioner set bolt has a left-hand thread. The drive belt tensioner set bolt loosens when it is turned clockwise. Remove the fan and generator V belt. Release the drive belt tensioner. (Scheme 7): Turning Drive Belt Tensioner Set Bolt Counterclockwise
7. REMOVE VANE PUMP ASSEMBLY Remove the return hose, 2 vacuum hoses and 3 clips. Remove the pressure feed hose union bolt, pressure feed tube and gasket. Remove the 2 bolts, nut and vane pump.