Last Modified: 7-3-2017 6.8:8.0.40 Doc ID: RM0000017QD009X
Model Year Start: 2007 Model: LX470 Prod Date Range: [08/2006 -           ]
Title: SUPPLEMENTAL RESTRAINT SYSTEM: AIRBAG SYSTEM: B1148/36; Front Airbag Sensor RH Circuit Malfunction; 2007 MY LX470 [08/2006 -        ]

DTC

B1148/36

Front Airbag Sensor RH Circuit Malfunction

DESCRIPTION

The front airbag sensor RH circuit consists of the diagnosis circuit and frontal deceleration sensor, etc.

If receives signals from the frontal deceleration sensor, judges whether or not the SRS must be activated, and detects diagnosis system malfunction.

DTC B1148/36 is recorded when occurrence of a malfunction in the front airbag sensor RH is detected.

DTC No.

DTC Detection Condition

Trouble Area

B1148/36

Front airbag sensor RH malfunction
  • Front airbag sensor RH
  • Center airbag sensor assembly
  • Dash wire
  • Engine room main wire
  • No. 2 engine room wire

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1.

CHECK FOR DTC

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

(b) Clear the DTC stored in memory 2007 MY LX470 [08/2006 -        ]; SUPPLEMENTAL RESTRAINT SYSTEM: AIRBAG SYSTEM: DTC CHECK / CLEAR .

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

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

(e) Check the DTC 2007 MY LX470 [08/2006 -        ]; SUPPLEMENTAL RESTRAINT SYSTEM: AIRBAG SYSTEM: DTC CHECK / CLEAR .

OK:

DTC B1148/36 is output.

HINT:

Codes other than code B1148/36 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 to LOCK.

(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 front airbag sensor RH.

OK:

The connectors are connected.

NG

CONNECT CONNECTOR

OK

3.

CHECK WIRE HARNESS

(a) Using a service wire, connect +SR and -SR on the A16 front airbag sensor RH side connector between the front airbag sensor RH and the center airbag sensor.

(b) Measure the resistance between +SR and -SR on the C32 center airbag sensor side connector between the front airbag sensor RH and the center airbag sensor.

Standard resistance:

Below 1 Ω
NG

GO TO STEP 7

OK

4.

CHECK WIRE HARNESS (TO GROUND)

(a) Measure the resistance between the body ground and each of +SR and -SR on the C32 center airbag sensor side connector between the front airbag sensor RH and the center airbag sensor.

Standard resistance:

1 kΩ or higher
NG

GO TO STEP 9

OK

5.

CHECK WIRE HARNESS (TO B+)

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

(b) Turn the ignition switch to ON.

(c) Measure the voltage between the body ground and each of +SR and -SR on the C32 center airbag sensor side connector between the front airbag sensor RH and the center airbag sensor.

Standard voltage:

Below 1 V
NG

GO TO STEP 11

OK

6.

CHECK CENTER AIRBAG SENSOR ASSEMBLY

(a) Turn the ignition switch to LOCK.

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

(c) Connect the connector to the center airbag sensor.

(d) Change the front airbag sensor LH position with RH position.

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

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

(g) Clear the DTC stored in memory 2007 MY LX470 [08/2006 -        ]; SUPPLEMENTAL RESTRAINT SYSTEM: AIRBAG SYSTEM: DTC CHECK / CLEAR .

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

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

(j) Check the DTC 2007 MY LX470 [08/2006 -        ]; SUPPLEMENTAL RESTRAINT SYSTEM: AIRBAG SYSTEM: DTC CHECK / CLEAR .

OK:

DTC B1148/36 and B1149/37 are not output.

HINT:

Codes other than code B1148/36 or B1149/37 may be output at this time, but they are not relevant to this check.
NG

REPLACE FRONT AIRBAG SENSOR RH (DTC B1149/37 IS OUTPUT)

NG

REPLACE CENTER AIRBAG SENSOR ASSEMBLY (DTC B1148/36 IS OUTPUT)

OK

USE SIMULATION METHOD TO CHECK

7.

CHECK ENGINE ROOM MAIN WIRE

(a) Disconnect the engine room main wire connector on the center airbag sensor side.

(b) Using a service wire, connect +SR and -SR of the A16 engine room main wire connector on the front airbag sensor RH side.

(c) Measure the resistance between +SR and -SR of the EA1 engine room main wire connector on the center airbag sensor side.

Standard resistance:

Below 1 Ω
NG

REPAIR OR REPLACE ENGINE ROOM MAIN WIRE

OK

8.

CHECK NO. 2 ENGINE ROOM WIRE

(a) Disconnect the No. 2 engine room wire connector from the dash wire.

(b) Using a service wire, connect +SR and -SR of the EA1 No. 2 engine room wire connector on the engine room main wire side.

(c) Measure the resistance between +SR and -SR of the IT1 No. 2 engine room wire connector on the dash wire side.

Standard resistance:

Below 1 Ω
NG

REPAIR OR REPLACE NO. 2 ENGINE ROOM WIRE

OK

REPAIR OR REPLACE DASH WIRE

9.

CHECK ENGINE ROOM MAIN WIRE (TO GROUND)

(a) Disconnect the engine room main wire connector on the center airbag sensor side.

(b) Measure the resistance between the body ground and each of +SR and -SR of the EA1 engine room main wire connector on the center airbag sensor side.

Standard resistance:

1 MΩ or higher
NG

REPAIR OR REPLACE ENGINE ROOM MAIN WIRE

OK

10.

CHECK NO. 2 ENGINE ROOM WIRE (TO GROUND)

(a) Disconnect the No. 2 engine room wire connector from the dash wire.

(b) Measure the resistance between the body ground and each of +SR and -SR of the IT1 No. 2 engine room wire connector on the dash wire side.

Standard resistance:

1 MΩ or higher
NG

REPAIR OR REPLACE NO. 2 ENGINE ROOM WIRE

OK

REPAIR OR REPLACE DASH WIRE

11.

CHECK ENGINE ROOM MAIN WIRE (TO B+)

(a) Turn the ignition switch to LOCK.

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

(c) Disconnect the engine room main wire connector on the center airbag sensor side.

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

(e) Turn the ignition switch to ON.

(f) Measure the voltage between the body ground and each of +SR and -SR of the EA1 engine room main wire connector on the center airbag sensor side.

Standard voltage:

Below 1 V
NG

REPAIR OR REPLACE ENGINE ROOM MAIN WIRE

OK

12.

CHECK NO. 2 ENGINE ROOM WIRE (TO B+)

(a) Turn the ignition switch to LOCK.

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

(c) Disconnect the No. 2 engine room wire connector from the dash wire.

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

(e) Turn the ignition switch to ON.

(f) Measure the voltage between the body ground and each of +SR and -SR of the IT1 No. 2 engine room wire connector on the dash wire side.

Standard voltage:

Below 1 V
NG

REPAIR OR REPLACE NO. 2 ENGINE ROOM WIRE

OK

REPAIR OR REPLACE DASH WIRE