Last Modified: 6-7-2017 6.8:8.0.40 Doc ID: RM0000017QT006X
Model Year Start: 2007 Model: Land Cruiser Prod Date Range: [08/2006 -           ]
Title: SUPPLEMENTAL RESTRAINT SYSTEM: AIRBAG SYSTEM: B1153/25; Seat Position Airbag Sensor Circuit Malfunction; 2007 MY Land Cruiser [08/2006 -        ]

DTC

B1153/25

Seat Position Airbag Sensor Circuit Malfunction

DESCRIPTION

The seat position sensor circuit consists of the center airbag sensor and the seat position sensor.

DTC B1153/25 is recorded when a malfunction is detected in the seat position sensor circuit.

DTC No.

DTC Detection Condition

Trouble Area

B1153/25

Seat position sensor assembly malfunction
  • Seat position sensor
  • Center airbag sensor assembly
  • No. 1 floor wire
  • Front seat wire LH

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1.

CHECK FOR DTC

(a) Turn the ignition switch ON, and wait for at least 10 seconds.

(b) Clear the DTC stored in memory 2007 MY Land Cruiser [08/2006 -        ]; SUPPLEMENTAL RESTRAINT SYSTEM: AIRBAG SYSTEM: DTC CHECK / CLEAR .

(c) Turn the ignition switch OFF, and wait for at least 10 seconds.

(d) Turn the ignition switch ON, and wait for at least 10 seconds.

(e) Check for a DTC 2007 MY Land Cruiser [08/2006 -        ]; SUPPLEMENTAL RESTRAINT SYSTEM: AIRBAG SYSTEM: DTC CHECK / CLEAR .

OK:

DTC B1153/25 is output.

HINT:

Codes other than code B1153/25 may be output at this time, but they are not relevant to this check.
NG

USE SIMULATION METHOD TO CHECK

OK

2.

CHECK CONNECTION OF CONNECTOR

(a) Turn the ignition switch OFF.

(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

(c) Check that the connectors are properly connected to the center airbag sensor and the seat position sensor.

NG

CONNECT CONNECTOR

OK

3.

CHECK WIRE HARNESS

(a) Using a service wire, connect terminals LSP+ and LSP- of the S17 connector on the seat position sensor side between the center airbag sensor and the seat position sensor.

(b) Measure the resistance of the wire harness side connector.

Standard resistance:

Tester Connection

Specified Condition

C25-4 (LSP+)*1 - C25-3 (LSP-)*1

Below 1 Ω

C25-3 (LSP+)*2 - C25-8 (LSP-)*2

Below 1 Ω

HINT:

*1: w/ Side Airbag *2: w/o Side Airbag
NG

GO TO STEP 9

OK

4.

CHECK WIRE HARNESS (TO GROUND)

(a) Disconnect the service wire from the connector on the seat position sensor side.

(b) Measure the resistance of the wire harness side connector.

Standard resistance:

Tester Connection

Specified Condition

C25-4 (LSP+)*1 - Body ground

10 kΩ or higher

C25-3 (LSP-)*1 - Body ground

10 kΩ or higher

C25-3 (LSP+)*2 - Body ground

10 kΩ or higher

C25-8 (LSP-)*2 - Body ground

10 kΩ or higher

HINT:

*1: w/ Side Airbag *2: w/o Side Airbag
NG

GO TO STEP 10

OK

5.

CHECK WIRE HARNESS (TO B+)

(a) Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.

(b) Turn the ignition switch ON.

(c) Measure the voltage of the wire harness side connector.

Standard voltage:

Tester Connection

Specified Condition

C25-4 (LSP+)*1 - Body ground

Below 1 V

C25-3 (LSP-)*1 - Body ground

Below 1 V

C25-3 (LSP+)*2 - Body ground

Below 1 V

C25-8 (LSP-)*2 - Body ground

Below 1 V

HINT:

*1: w/ Side Airbag *2: w/o Side Airbag
NG

GO TO STEP 11

OK

6.

CHECK SEAT POSITION SENSOR ASSEMBLY

(a) Turn the ignition switch OFF.

(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

(c) Connect the connectors of the seat position sensor and the center airbag sensor.

(d) Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.

(e) Turn the ignition switch ON, and wait for at least 10 seconds.

(f) Clear the DTC stored in memory 2007 MY Land Cruiser [08/2006 -        ]; SUPPLEMENTAL RESTRAINT SYSTEM: AIRBAG SYSTEM: DTC CHECK / CLEAR .

(g) Turn the ignition switch OFF, and wait for at least 10 seconds.

(h) Turn the ignition switch ON, and wait for at least 10 seconds.

(i) Check for a DTC 2007 MY Land Cruiser [08/2006 -        ]; SUPPLEMENTAL RESTRAINT SYSTEM: AIRBAG SYSTEM: DTC CHECK / CLEAR .

OK:

DTC B1153/25 is not output.

HINT:

Codes other than code B1153/25 may be output at this time, but they are not relevant to this check.
OK

USE SIMULATION METHOD TO CHECK

NG

7.

REPLACE SEAT POSITION SENSOR ASSEMBLY

(a) Turn the ignition switch OFF.

(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

(c) Replace the seat position sensor.

HINT:

Perform the inspection using parts from a normal vehicle.

NEXT

8.

CHECK CENTER AIRBAG SENSOR ASSEMBLY

(a) Connect the negative (-) terminal cable to the battery, and wait at least for 2 seconds.

(b) Turn the ignition switch ON, and wait for at least 10 seconds.

(c) Clear the DTC stored in memory 2007 MY Land Cruiser [08/2006 -        ]; SUPPLEMENTAL RESTRAINT SYSTEM: AIRBAG SYSTEM: DTC CHECK / CLEAR .

(d) Turn the ignition switch OFF, and wait for at least 10 seconds.

(e) Turn the ignition switch ON, and wait for at least 10 seconds.

(f) Check for a DTC 2007 MY Land Cruiser [08/2006 -        ]; SUPPLEMENTAL RESTRAINT SYSTEM: AIRBAG SYSTEM: DTC CHECK / CLEAR .

OK:

DTC B1153/25 is not output

HINT:

DTCs other that DTC B1153/25 may be output at this time, but they are not relevant to this check.
NG

REPLACE CENTER AIRBAG SENSOR ASSEMBLY

OK

USE SIMULATION METHOD TO CHECK

9.

CHECK FRONT SEAT WIRE LH

(a) Disconnect the front seat wire LH connector from the No. 1 floor wire.

(b) Using a service wire, connect terminals LSP+ and LSP- of the S17 front seat wire LH connector on the seat position sensor side.

(c) Measure the resistance of the wire harness side connector.

Standard resistance:

Tester Connection

Specified Condition

BM4-1 (LSP+) - BM4-2 (LSP-)

Below 1 Ω
NG

REPLACE FRONT SEAT WIRE LH

OK

REPLACE NO. 1 FLOOR WIRE

10.

CHECK FRONT SEAT WIRE LH (TO GROUND)

(a) Disconnect the front seat wire LH connector from the No. 1 floor wire.

(b) Disconnect the service wire from the front seat wire LH connector on the seat position sensor side.

(c) Measure the resistance of the wire harness side connector.

Standard resistance:

Tester Connection

Specified Condition

BM4-1 (LSP+) - Body ground

10 kΩ or higher

BM4-2 (LSP-) - Body ground

10 kΩ or higher
NG

REPLACE FRONT SEAT WIRE LH

OK

REPLACE NO. 1 FLOOR WIRE

11.

CHECK FRONT SEAT WIRE LH (TO B+)

(a) Disconnect the front seat wire LH connector from the No. 1 floor wire.

(b) Turn the ignition switch ON.

(c) Measure the voltage of the wire harness side connector.

Standard voltage:

Tester Connection

Specified Condition

BM4-1 (LSP+) - Body ground

Below 1 V

BM4-2 (LSP-) - Body ground

Below 1 V
NG

REPLACE FRONT SEAT WIRE LH

OK

REPLACE NO. 1 FLOOR WIRE