Inspection Procedure

NOTE:

Before performing troubleshooting, inspect the connectors of related circuits.
Before replacing the suspension control ECU, perform all of the following again: 1) symptom simulation (see ELECTRONIC CIRCUIT INSPECTION PROCEDURE ); 2) DTC inspection; and 3) Intelligent tester or Techstream inspection (Data List or Active Test). If no malfunctions are found in other areas, replace the suspension control ECU.
If the suspension control ECU or height control sensor is replaced, the vehicle height offset calibration must be performed (see INITIALIZATION ).
The system may output DTC C1761/61 even when the system is normal if one of the following occurs: 1) the vehicle is full of passengers and the luggage compartment is full; 2) the vehicle is being driven or is stopped on an irregular surface; or 3) the air ducts are frozen.

CLEAR DTC
1. Clear the DTC (see DTC CHECK / CLEAR ).
CHECK AIR LEAKAGE
1. Check for air leakage (see OPERATION CHECK ).
  OK: No leaks.
NG: REPAIR OR REPLACE AIR TUBE

OK: GO TO NEXT STEP
INSPECT IF FRONT HEIGHT CONTROL VALVE IS STUCK
1. Remove the front height control valve (see REMOVAL ).
2. Check the front height control valve RH valve.
  1. Connect terminal 1 (RH+) to the battery positive (+) terminal, and terminal 2 (E) to the battery negative (-) terminal.
  2. Check the operating sound of the height control valve.
    OK: It makes an operating sound (click).
  Fig 1: Checking Front Height Control Valve RH
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Check the front height control valve LH valve.
  1. Connect terminal 3 (LH+) to the battery positive (+) terminal, and terminal 2 (E) to the battery negative (-) terminal.
  2. Check the operating sound of the height control valve.
    OK: It makes an operating sound (click).
  Fig 2: Checking Front Height Control Valve LH
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPLACE FRONT HEIGHT CONTROL VALVE (See REMOVAL )

OK: GO TO NEXT STEP
INSPECT IF REAR HEIGHT CONTROL VALVE IS STUCK
1. Remove the rear height control valve (see REMOVAL ).
2. Check the rear height control valve RH valve.
  1. Connect terminal 1 (RH+) to the battery positive (+) terminal, and terminal 2 (E) to the battery negative (-) terminal.
  2. Check the operating sound of the height control valve.
    OK: It makes an operating sound (click).
  Fig 3: Checking Rear Height Control Valve RH
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Check the rear height control valve LH valve.
  1. Connect terminal 3 (LH+) to the battery positive (+) terminal, and terminal 2 (E) to the battery negative (-) terminal.
  2. Check the operating sound of the height control valve.
  Fig 4: Checking Rear Height Control Valve LH
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPLACE REAR HEIGHT CONTROL VALVE (See REMOVAL )

OK: GO TO NEXT STEP
INSPECT IF HEIGHT CONTROL COMPRESSOR IS STUCK
1. Remove the height control compressor (see REMOVAL ).
2. Inspect if exhaust valve is stuck:
  1. Connect terminal 1 (B) to the battery positive (+) terminal, and terminal 2 (L) to the battery negative (-) terminal.
  2. Check the operating sound of the height control valve.
    OK: It makes an operating sound (click).
  Fig 5: Inspecting Exhaust Valve If Stuck
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Inspect if compressor is stuck:
  1. Connect terminal 1 (B) to the battery positive (+) terminal, and terminal 2 (E) to the battery negative (-) terminal.
  2. Check that the motor rotates.
    CAUTION: If the compressor is shorted, locked, or has a similar type of malfunction, a large amount of voltage will be flowing. Therefore, if the motor does not operate, immediately stop this inspection.
    
    NOTE: Do not allow the motor to operate for approximately 60 seconds or more.
    
    Fig 6: Inspecting Compressor If Stuck
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    OK: Motor operates
NG: REPLACE HEIGHT CONTROL COMPRESSOR (See REMOVAL )

OK: GO TO NEXT STEP

INSPECT SUSPENSION CONTROL RELAY (AIRSUS)

Turn the engine switch off.
Remove the suspension control relay from the engine room No. 1 relay block.

Measure the resistance according to the value(s) in the table below.

Standard resistance

SUSPENSION CONTROL RELAY (AIRSUS)

Tester Connection	Condition	Specified Condition
3-5	When battery voltage is not applied to terminal 1 and 2	10 kΩ or higher
3-5	When battery voltage is applied to terminal 1 and 2	Below 1 Ω

Fig 7: Inspecting Suspension Control Relay (Airsus)

NG: REPLACE SUSPENSION CONTROL RELAY

OK: REPLACE SUSPENSION CONTROL ECU (See REMOVAL )