C1736

SUSPENSION CONTROL: ACTIVE HEIGHT CONTROL SUSPENSION: C1736,C1737: Front Suspension Control Valve RH Malfunction


DESCRIPTION

In order to decrease roll angle/pitch angle, the suspension control ECU turns the spring rate switching valve in the front suspension control valve off/on to change the fluid lines when the acceleration sensor or yaw rate sensor signal is input into the suspension control ECU. Normally, the spring rate switching valve is open.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
- Before performing troubleshooting, inspect the connectors of related circuits.
- If the suspension control ECU or height control sensor is replaced, the vehicle height offset calibration must be performed Programming and Relearning.

HINT
Power is supplied to the front suspension control valve and No. 1 height control valve from the suspension control ECU. If a short occurs in the power supply circuit in the No. 1 height control valve, DTC C1736 and/or C1737 will be stored. In this case, DTC C1741, C1742, C1743, C1744, C1753, C1754 and/or C1755 will also be stored.

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (FRONT SPRING RATE SWITCHING VALVE)

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(c) Start the engine and turn the Techstream on.

(d) Enter the following menus: Chassis / AHC / Active Test.

(e) Check the operation of the front spring rate switching valve solenoid when operating the solenoid with the Techstream.

AHC





OK:

The front spring rate switching valve operates.

NG -- CHECK HARNESS AND CONNECTOR (SUSPENSION CONTROL ECU - FRONT SUSPENSION CONTROL VALVE)
OK -- Continue to next step.

2. RECONFIRM DTC OUTPUT

(a) Clear the DTCs Programming and Relearning.

(b) Perform a road test.

(c) Check for DTCs.

Result





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

A -- REPLACE SUSPENSION CONTROL ECU Removal

3. CHECK HARNESS AND CONNECTOR (SUSPENSION CONTROL ECU - FRONT SUSPENSION CONTROL VALVE)

(a) Disconnect the N9*1 and/or N11*2 front suspension control valve connector.

HINT
*1: for RH

*2: for LH

(b) Disconnect the K32 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.

4. CHECK HARNESS AND CONNECTOR (BODY GROUND BETWEEN ECU - FRONT SUSPENSION CONTROL VALVE)

(a) Disconnect the K32 ECU connector.

(b) Disconnect the N9*1 and/or N11*2 front suspension control valve connector.

HINT
*1: for RH

*2: for LH

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





Standard Resistance:





NG -- CHECK HARNESS AND CONNECTOR (BODY GROUND BETWEEN ECU - NO. 1 HEIGHT CONTROL VALVE)
OK -- Continue to next step.

5. INSPECT FRONT SUSPENSION CONTROL VALVE

(a) Connect the N9 and/or N11 front suspension control valve connector.

(b) Disconnect the K32 ECU connector.





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

Standard Resistance:





NG -- REPLACE FRONT SUSPENSION CONTROL VALVE Removal

OK -- REPLACE SUSPENSION CONTROL ECU Removal

6. CHECK HARNESS AND CONNECTOR (BODY GROUND BETWEEN ECU - NO. 1 HEIGHT CONTROL VALVE)

(a) Disconnect the N3 No. 1 height control valve connector.

(b) Disconnect the K32 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.

7. CHECK HARNESS AND CONNECTOR (NO. 1 HEIGHT CONTROL VALVE - SUSPENSION CONTROL ECU) C1741

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE NO. 1 HEIGHT CONTROL VALVE Removal