Last Modified: 11-29-2007 1.6 C
Service Category: Suspension Section: Suspension Control System
Model Year: 2008 Model: Sequoia Doc ID: RM000001N97008X
Title: SUSPENSION CONTROL: AIR SUSPENSION SYSTEM (w/o AVS): DESCRIPTION (2008 Sequoia)

DTC

C1761

Continuous Electric Current to Height Control Compressor Motor

DESCRIPTION

DTC Code

Detection Condition

Trouble Area

C1761*1

With the AIR SUS relay activated, the vehicle does not go up to the standard vehicle height after 90 seconds have elapsed.
  • Air leakage from the air tube or each valve
  • Clogging in the air tube or each valve
  • AIR SUS relay
  • Leveling solenoid valve (No. 2 height control valve)
  • Gate solenoid valve (No. 2 height control valve)
  • Exhaust solenoid valve (No. 1 height control compressor)
  • Height control sensors
  • Wire harness or connector
  • Height control compressor
  • Suspension control ECU

HINT:

*1: The compressor motor operates continuously to raise vehicle height and allows electric current flow to the AIR SUS relay for 90 seconds or more under the following conditions:

  • Vehicle height control is attempted on a steep slope when the vehicle is overloaded.
  • The compressor remains on for an excessive period of time or repeatedly turns on and off because of continuous height control switch operation.
  • If the compressor remains on because the vehicle is jacked up, the vehicle height is set at a position lower than normal while the engine is running and then the vehicle height control function raises the vehicle.

    Thus DTC C1761 may be output and vehicle height control may be suspended. (This is not electrically abnormal.) In this case, however, the vehicle height operation is resumed approximately 10 minutes after the ignition switch is turned ON after the ECU detects the first error. If the ECU detects another error, it takes 70 minutes until control is resumed.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1.

INSPECT FOR AIR LEAK

(a) Check for air leakage SUSPENSION CONTROL: SUSPENSION CONTROL SYSTEM: ADJUSTMENT (2008 Sequoia)+ .

OK:

No leaks.

OK

2.

PERFORM ACTIVE TEST USING TECHSTREAM (EXHAUST SOLENOID)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON, and turn the Techstream main switch on.

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

Air Suspension

Tester Display

Test Part

Control Range

Diagnostic Note

Exhaust Solenoid

Exhaust solenoid valve

ON or OFF

Operation sound of solenoid (clicking sound) can be heard

OK:

Operation of solenoid (clicking sound) can be heard

OK

3.

PERFORM ACTIVE TEST USING TECHSTREAM (REAR GATE SOLENOID)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON, and turn the Techstream main switch on.

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

Air Suspension

Tester Display

Test Part

Control Range

Diagnostic Note

Rear Gate Solenoid

Gate solenoid valve/

ON or OFF

Operation sound of solenoid (clicking sound) can be heard

OK:

Operation of solenoid (clicking sound) can be heard

OK

4.

PERFORM ACTIVE TEST USING TECHSTREAM (REAR LEVELING SOLENOID)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON, and turn the Techstream main switch on.

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

Air Suspension

Tester Display

Test Part

Control Range

Diagnostic Note

Rear Leveling Solenoid

Leveling solenoid valve

ON or OFF

Operation sound of solenoid (clicking sound) can be heard

OK:

Operation of solenoid (clicking sound) can be heard

OK

5.

INSPECT SUSPENSION CONTROL RELAY (AIR SUS)

(a) Turn the ignition switch off.

(b) Remove the AIR SUS relay from the engine room relay block.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

3 - 5

When 12 V battery voltage is not applied to terminal 1 and 2

10 kΩ or higher

When 12 V battery voltage is applied to terminal 1 and 2

Below 1 Ω
OK

6.

CHECK HARNESS AND CONNECTOR (COMPRESSOR - BATTERY AND BODY GROUND)

(a) Remove the AIR SUS relay from the engine room relay block.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

Relay block AIR SUS relay terminal 5 - Body ground

Always

11 to 14 V

(c) Disconnect the Q7 compressor connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Relay block AIR SUS relay terminal 3 - Q7-1 (B)

Always

Below 1 Ω

Relay block AIR SUS relay terminal 3 or Q7-1 (B) - Body ground

Always

10 kΩ or higher

Q7-2 (E) - Body ground

Always

Below 1 Ω
OK

7.

CHECK VEHICLE HEIGHT

(a) Check the vehicle height SUSPENSION CONTROL: SUSPENSION CONTROL SYSTEM: ADJUSTMENT (2008 Sequoia) .

OK

8.

CHECK FOR DTC

(a) Clear the DTC SUSPENSION CONTROL: AIR SUSPENSION SYSTEM (w/o AVS): DTC CHECK / CLEAR (2008 Sequoia) .

(b) Check for DTC SUSPENSION CONTROL: AIR SUSPENSION SYSTEM (w/o AVS): DTC CHECK / CLEAR (2008 Sequoia) .

Result

Result

Proceed to

DTC is output

A

DTC is not output

B
A