DTC C1744/44: Tank Solenoid Valve Circuit: Procedure

1. Check DTCs. Refer to DTC CHECK / CLEAR .
   1. Confirm if the DTC C1761/61 and/or C1774/74 is recorded.

      OK

      DTC C1761/61 and/or C1774/74 is not output.

      HINT: 

      If either DTCC1761/61 (ECU malfunction). Refer to DTC C1761/61: ECU Malfunction  or C1774/74 (power source circuit). Refer to DTC C1774/74: Power Source Circuit  is displayed, carry out the necessary inspection. If they are output at the same time, carry out the necessary inspection for DTC C1774/74 first.

NG → REPAIR CIRCUIT INDICATED BY OUTPUT CODE 

OK: Go to next step 

HINT: 

When not using Techstream, go to step  3.

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to the ON position, and push the Techstream main switch on.
3. Select the item below in the ACTIVE TEST, and operate it with the Techstream.

   Air suspension

   Item	Vehicle Condition / Test Details	Diagnostic Note
   Low Pressure Tank Solenoid	Turn OFF tank solenoid valve one second after turning it ON	Operation of solenoid (clicking sound) can be heard

4. Check whether the tank solenoid valve has a continuity (will vibrate).

   OK

   The solenoid makes sound, and the tank solenoid valve has a continuity (will vibrate).

NG → Go to next step 

OK → REPLACE SUSPENSION CONTROL ECU 

1. Disconnect the tank solenoid valve connector.
   Fig 1: Identifying Tank Solenoid Valve Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the values in the table below.

   Standard resistance

   Tester Connection	Specified Condition
   1 (SLLO) - 2 (GND)	12 +- 2 Ω

3. Check the operating sound of the tank solenoid valve when positive battery voltage is applied to the terminals.

   Battery Positive	Battery Negative
   1 (SLLO)	2 (GND)

   OK

   It should make an operating sound (click).

   HINT: 

   When a malfunction is found in the tank solenoid valve, replace the pneumatic tank assembly.

NG → REPLACE PNEUMATIC W/TUBE TANK ASSEMBLY 

OK: Go to next step 

1. Disconnect the suspension control ECU S14 connector.
   Fig 2: Identifying Suspension Control ECU S14 Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the values in the table below.

   Standard resistance

   Tester Connection	Specified Condition
   S14-7 (SLLO) - P7-1 (SLLO)	Below 1 Ω
   S14-7 (SLLO) - Body ground	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Measure the resistance according to the values in the table below.
   Fig 3: Identifying Tank Solenoid Valve Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard resistance

   Tester Connection	Specified Condition
   P7-2 (GND) - Body ground	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE SUSPENSION CONTROL ECU