C1747

SUSPENSION CONTROL: AIR SUSPENSION SYSTEM: C1747/47: Leveling Solenoid Valve Circuit
C1747/47 - Leveling Solenoid Valve Circuit

DESCRIPTION

The suspension control ECU opens the leveling solenoid valve (No. 2 height control valve) to allow compressed air to flow into the height control cylinder (pneumatic cylinder) and raise the vehicle height.

The No. 2 height control valve consists of a leveling solenoid valve and a gate solenoid valve.

The leveling solenoid valve opens and closes the passage between the height control compressor and the height control cylinder (pneumatic cylinder).





HINT
- Once the suspension control ECU stores DTC C1747/47 in memory, vehicle height control is suspended until a normal signal is input to the suspension control ECU from the height control valves. However, control is resumed if the engine switch is turned off and then on (IG) again.
- Malfunction in the leveling solenoid valve:
Height control operation is suspended and the height control indicator does not change by operating the height control switch.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
When replacing the suspension control ECU, perform registration Programming and Relearning.

HINT
If DTC C1782/82 is output at the same time as C1747/47, perform the inspection necessary for DTC C1782/82 first C1782.

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (REAR LEVELING SOLENOID)

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG).

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / Air suspension / Active Test.

Air Suspension





OK:

Operation of solenoid (clicking sound) can be heard.

Result





C -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

B -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Air Suspension System
A -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (LEVELING SOLENOID VALVE - SUSPENSION CONTROL ECU AND BODY GROUND)

(a) Disconnect the S6 leveling solenoid valve connector.

(b) Disconnect the A11 suspension control ECU connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. INSPECT NO. 2 HEIGHT CONTROL VALVE (LEVELING SOLENOID VALVE)

(a) Turn the engine switch off.

(b) Remove the No. 2 height control valve Removal.

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





Standard Resistance:





Text in Illustration





(d) Connect the positive (+) lead of the battery to terminal 3 (RH+) and the negative (-) lead to terminal 2 (E) of the solenoid valve connector. Then check that the valve makes an operating sound.

OK:

Operation of solenoid (clicking sound) can be heard.

NG -- REPLACE NO. 2 HEIGHT CONTROL VALVE ASSEMBLY Removal

OK -- REPLACE SUSPENSION CONTROL ECU Removal