Last Modified: 7-3-2017 6.8:8.0.40 Doc ID: RM000001CTX004X
Model Year Start: 2007 Model: LX470 Prod Date Range: [08/2006 -           ]
Title: SUSPENSION CONTROL: ACTIVE HEIGHT CONTROL SUSPENSION: C1776/76; Speed Sensor Circuit; 2007 MY LX470 [08/2006 -        ]

DTC

C1776/76

Speed Sensor Circuit

DESCRIPTION

DTC No.

DTC Detection Condition

Trouble Area

C1776/76

While the vehicle is stopped, when the front height control sensor signal is input.
  • Front speed sensor circuit
  • Front height control sensor RH
  • Front height control sensor LH
  • Rear height control sensor
  • Suspension control ECU
  • Wire harness

Fail-safe function:

If any trouble occurs, the height control is prohibited again after adjusting the vehicle to the standard height in case that the height is higher than the standard or to the lowest wheel of the 4 wheels in case that the height is lower the standard.

WIRING DIAGRAM

INSPECTION PROCEDURE

If a DTC is output for the skid control ECU, first troubleshoot it.

HINT:

  • When using the intelligent tester start from *1. When not using the intelligent tester, start from *2.
  • Before troubleshooting for this DTC, make sure no skid control ECU DTCs are present.

PROCEDURE

1.

READ VALUE USING INTELLIGENT TESTER (HEIGHT CONTROL SENSOR)*1

(a) Connect the intelligent tester (with CAN VIM) to the DLC3.

(b) Start the engine and push the intelligent tester main switch ON.

(c) Select the DATA LIST mode on the intelligent tester.

(d) Check that the vehicle height value of the height control sensor displayed by the intelligent tester is changing when pushing the UP or DOWN button of the height select switch.

OK:

Vehicle height value must be changing.

NG

GO TO STEP 3

OK

REPLACE SUSPENSION CONTROL ECU

2.

CHECK SUSPENSION CONTROL ECU*2

(a) Remove the suspension control ECU with connectors still connected.

(b) Turn the ignition switch ON.

(c) Measure the voltage between terminals SHB and SHG of the suspension control ECU connector.

Standard voltage:

Tester Connection

Specified Condition

S7-1 (SHB) - S7-9 (SHG)

Approximately 5 V
NG

GO TO STEP 4

OK

3.

INSPECT HEIGHT CONTROL SENSOR (FRONT RH, FRONT LH AND REAR)

(a) Disconnect the height control sensor connector.

(b) Remove the height control sensor.

(c) Connect 3 dry batteries of 1.5 V in series.

(d) Connect terminal 2 to the batteries' positive (+) terminal, and terminal 3 to the batteries' negative (-) terminal, then apply voltage about 4.5 V between terminals 2 and 3.

(e) Measure the voltage between terminals 1 and 3, when the height control sensor link is slowly moved up and down.

Standard voltage:

Tester Connection

Sensor Link Position

Specified Condition

1 - 3

Max. HI

Approximately 4.05 V

1 - 3

N

Approximately 2.25 V

1 - 3

Min. LO

Approximately 0.45 V

(f) Disconnect the height control sensor connector.

(g) Remove the height control sensor.

(h) Connect 3 dry batteries of 1.5 V in series.

(i) Connect terminal 1 to the batteries' positive (+) terminal, and terminal 3 to the batteries' negative (-) terminal, then apply voltage about 4.5 V between terminals 1 and 3.

(j) Measure the voltage between terminals 2 and 3 when the height control sensor link is slowly moved up and down.

Standard voltage:

Tester Connection

Sensor Link Position

Specified Condition

2 - 3

Max. HI

Approximately 4.05 V

2 - 3

N

Approximately 2.25 V

2 - 3

Min. LO

Approximately 0.45 V
NG

REPLACE HEIGHT CONTROL SENSOR (FRONT RH, FRONT LH AND REAR)

OK

4.

CHECK WIRE HARNESS (HEIGHT CONTROL SENSOR (FRONT RH, FRONT LH AND REAR) - SUSPENSION CONTROL ECU)
NG

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

REPLACE SUSPENSION CONTROL ECU