Last Modified: 7-3-2017 6.8:8.0.40 Doc ID: RM000001CTL004X
Model Year Start: 2007 Model: LX470 Prod Date Range: [08/2006 -           ]
Title: SUSPENSION CONTROL: ACTIVE HEIGHT CONTROL SUSPENSION: C1787/87; Absorber Control Switch Circuit; 2007 MY LX470 [08/2006 -        ]

DTC

C1787/87

Absorber Control Switch Circuit

DESCRIPTION

This circuit is sending the signal to the ECU to switch over to the damping mode select by the damping mode select switch.

DTC No.

DTC Detection Condition

Trouble Area

C1787/87

TSW1 and TSW2 of damping mode select switch signals do not change.
  • Suspension control switch (Damping mode select switch)
  • Suspension control ECU
  • Wire harness

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

When using the intelligent tester, start from *1. When not using the intelligent tester, start from *2.

PROCEDURE

1.

READ VALUE USING INTELLIGENT TESTER (DAMPING MODE SELECT SWITCH)*1

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

(b) Turn the ignition switch ON and push the intelligent tester main switch ON.

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

(d) Check the damping mode select switch condition displayed on the intelligent tester when changing the damping mode select switch to each mode.

OK:

Damping mode select switch must display the condition as the following table.

Switch Position

Condition

COMFORT

ON is displayed for TSW1 of damping mode select switch condition.

OFF is displayed for TSW2 of damping mode select switch condition.

NORMAL

ON is displayed for TSW1 and TSW2 of damping mode select switch condition.

SPORT 1

OFF is displayed for TSW1 of damping mode select switch condition.

ON is displayed for TSW2 of damping mode select switch condition.

SPORT 2

OFF is displayed for TSW1 and TSW2 of damping mode select switch condition.
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 TSW1 and TSW2 of the suspension control ECU connector and body ground when changing the damping mode select switch to each mode.

Standard voltage:

Tester Connection

Condition

Specified Condition

S7-5 (TSW1) - Body ground

COMFORT

9 to 14 V

S7-5 (TSW1) - Body ground

NORMAL

9 to 14 V

S7-5 (TSW1) - Body ground

SPORT 1

Below 1.5 V

S7-5 (TSW1) - Body ground

SPORT 2

Below 1.5 V

S7-13 (TSW2) - Body ground

COMFORT

Below 1.5 V

S7-13 (TSW2) - Body ground

NORMAL

9 to 14 V

S7-13 (TSW2) - Body ground

SPORT 1

9 to 14 V

S7-13 (TSW2) - Body ground

SPORT 2

Below 1.5 V
NG

REPLACE SUSPENSION CONTROL ECU

OK

3.

INSPECT SUSPENSION CONTROL SWITCH (DAMPING MODE SELECT SWITCH)

(a) Remove the suspension control switch.

(b) Disconnect the suspension control switch (for damping mode select switch) connector.

(c) Measure the resistance between terminals 2, 7 and 4 of the suspension control switch (for damping mode select switch) connector when changing the damping mode select switch to each mode.

Standard resistance:

Tester Connection

Condition

Specified Condition

2 - 4

COMFORT

Below 1 Ω

2 - 4

NORMAL

Below 1 Ω

2 - 4

SPORT 1

10 kΩ or higher

2 - 4

SPORT 2

10 kΩ or higher

7 - 4

COMFORT

10 kΩ or higher

7 - 4

NORMAL

Below 1 Ω

7 - 4

SPORT 1

Below 1 Ω

7 - 4

SPORT 2

10 kΩ or higher
NG

REPLACE SUSPENSION CONTROL SWITCH (DAMPING MODE SELECT SWITCH)

OK

4.

CHECK WIRE HARNESS (SUSPENSION CONTROL SWITCH (DAMPING MODE SELECT SWITCH) - SUSPENSION CONTROL ECU)
NG

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

REPLACE SUSPENSION CONTROL ECU