Inspection Procedure

1. GO TO NEXT STEP 

1. NG: REPAIR OR REPLACE AIR TUBE 
2. OK: Go To Next Step 

When using hand-held tester: 

1. Connect the hand-held tester to DLC3.
2. Turn the ignition switch ON, and push the hand-held tester main switch ON.
3. Select the item "LEVEL SOL REAR", "GATE SOL REAR", "LOW PRS TNK SOL" in the ACTIVE TEST, and operate it with the hand-held tester.

   HINT:

   The exhaust solenoid valve cannot be tested in ACTIVE TEST.

4. Check whether the solenoid makes sound.
5. Check whether the height control solenoid valve has a continuity (will vibrate).
   • Standard:  The solenoid makes sound, the height control solenoid valve has a continuity (will vibrate).

When not using hand-held tester: 

1. Disconnect the valve connector.
2. Check the operating sound of the valves when battery positive voltage is applied to the terminals .
   SOLENOID VALVE BATTERY VOLTAGE
   
   

   Solenoid valve	Battery positive	Battery negative
   Gate solenoid valve	1	2
   Leveling solenoid valve	3	2
   Exhaust solenoid valve	1	2
   Tank solenoid valve	2	1

   • Standard:  It make an operating sound (click).

HINT:

• When a malfunction is found in the gate solenoid valve, the leveling valve or the tank solenoid valve, replace the height control reservoir assy.
• When a malfunction is found in the exhaust solenoid valve, replace the height control compressor assy.
  Fig 1: Checking Operating Sound Of Height Control Solenoid Valve Or Exhaust Solenoid Valve

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. NG: REPLACE HEIGHT CONTROL RESERVOIR ASSY 
2. NG: REPLACE HEIGHT CONTROL COMPRESSOR ASSY 
3. OK: Go To Next Step 

1. Inspect and adjust the height control sensor link sub-assy (See ON-VEHICLE INSPECTION ).

1. Clear the DTC and repeat the procedure to re-check it (See PRE-CHECK ).

HINT:

If the DTC C1751/51 is still output, proceed to the next step.

1. Air tube is clogged (See ON-VEHICLE INSPECTION )
2. Compressor is faulty (See REPLACEMENT )
3. Relief valve is faulty (See REPLACEMENT )
4. Height control sensor sub-assy rear is faulty (See REPLACEMENT )
5. Foreign material entered in the height control solenoid valve (gate solenoid valve) and the exhaust solenoid valve
6. Suspension control ECU malfunctions (See TERMINALS OF ECU )