SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: DESCRIPTION (2008 LX570)

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Last Modified: 11-27-2007		1.6 C
Service Category: Vehicle Interior	Section: Supplemental Restraint Systems
Model Year: 2008	Model: LX570	Doc ID: RM000000YDZ037X
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: DESCRIPTION (2008 LX570)

DTC

B1815/54

Short in Front Passenger Side Squib 2nd Step Circuit

DTC

B1816/54

Open in Front Passenger Side Squib 2nd Step Circuit

DTC

B1817/54

Short to GND in Front Passenger Side Squib 2nd Step Circuit

DTC

B1818/54

Short to B+ in Front Passenger Side Squib 2nd Step Circuit

DESCRIPTION

The front passenger side squib 2nd step circuit consists of the center airbag sensor and the front passenger airbag.

The circuit instructs the SRS to deploy when deployment conditions are met.

These DTCs are stored when a malfunction is detected in the front passenger side squib 2nd step circuit.

DTC Code	DTC Detection Condition	Trouble Area
B1815/54	When one of the following conditions is met: The center airbag sensor receives a line short circuit signal 5 times in the front passenger side squib 2nd step circuit during the primary check. A front passenger side squib 2nd step malfunction. A center airbag sensor malfunction.	Instrument panel wire Instrument panel wire assembly Front passenger airbag assembly (Front passenger side squib 2nd step) Center airbag sensor assembly
B1816/54	When one of the following conditions is met: The center airbag sensor receives an open circuit signal in the front passenger side squib 2nd step circuit for 2 seconds. A front passenger side squib 2nd step malfunction. A center airbag sensor malfunction.	Instrument panel wire Instrument panel wire assembly Front passenger airbag assembly (Front passenger side squib 2nd step) Center airbag sensor assembly
B1817/54	When one of the following conditions is met: The center airbag sensor receives a short circuit to ground signal in the front passenger side squib 2nd step circuit for 0.5 seconds. A front passenger side squib 2nd step malfunction. A center airbag sensor malfunction.	Instrument panel wire Instrument panel wire assembly Front passenger airbag assembly (Front passenger side squib 2nd step) Center airbag sensor assembly
B1818/54	When one of the following conditions is met: The center airbag sensor receives a short circuit to B+ signal in the front passenger side squib 2nd step circuit for 0.5 seconds. A front passenger side squib 2nd step malfunction. A center airbag sensor malfunction.	Instrument panel wire Instrument panel wire assembly Front passenger airbag assembly (Front passenger side squib 2nd step) Center airbag sensor assembly

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

w/ Navigation system:

After the engine switch is turned off, the HDD navigation system requires approximately 6 minutes to record various types of memory and settings. As a result, after turning the engine switch off, wait 6 minutes or more before disconnecting the cable from the negative (-) battery terminal.

When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected .

HINT:

To perform the simulation method, enter the "check mode (signal check) with the Techstream , and then wiggle each connector of the airbag system or drive the vehicle on various type of road .

PROCEDURE

1.	CHECK FRONT PASSENGER AIRBAG (FRONT PASSENGER SIDE SQUIB 2ND STEP)

(a) Turn the engine switch off.

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

(d) Connect the white wire side of SST (resistance: 2.1 Ω) to connector E (black connector).

CAUTION:

Never connect the tester to the front passenger airbag (front passenger side squib 2nd step) for measurement, as this may lead to a serious injury due to airbag deployment.

NOTICE:

Do not forcibly insert SST into the terminals of the connector when connecting SST.
Insert SST straight into the terminals of the connector.

SST: 09843-18061

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

(f) Turn the engine switch on (IG), and wait for at least 60 seconds.

(g) Clear the DTCs .

(h) Turn the engine switch off.

(i) Turn the engine switch on (IG), and wait for at least 60 seconds.

(j) Check for DTCs .

OK:

DTC B1815, B1816, B1817 or B1818 is not output.

HINT:

Codes other than DTC B1815, B1816, B1817 and B1818 may be output at this time, but they are not related to this check.

2.	CHECK CONNECTOR

(a) Turn the engine switch off.

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

(d) Check that the instrument panel wire connectors (on the front passenger airbag side) are not damaged.

OK:

The lock button is not disengaged, and the claw of the lock is not damaged or deformed.

3.	CHECK FRONT PASSENGER SIDE SQUIB 2ND STEP CIRCUIT

(a) Disconnect the connectors from the center airbag sensor.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
b1-1 (P2+) - Body ground	Engine switch on (IG)	Below 1 V
b1-2 (P2-) - Body ground	Engine switch on (IG)	Below 1 V

(d) Turn the engine switch off.

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
b1-1 (P2+) - b1-2 (P2-)	Always	Below 1 Ω

(g) Release the activation prevention mechanism built into connector B .

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
b1-1 (P2+) - b1-2 (P2-)	Always	1 MΩ or higher
b1-1 (P2+) - Body ground	Always	1 MΩ or higher
b1-2 (P2-) - Body ground	Always	1 MΩ or higher

4.	CHECK CENTER AIRBAG SENSOR

(a) Connect the connectors to the front passenger airbag and the center airbag sensor.

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

(d) Clear the DTCs .

(e) Turn the engine switch off.

(f) Turn the engine switch on (IG), and wait for at least 60 seconds.

(g) Check for DTCs .

OK:

DTC B1815, B1816, B1817 or B1818 is not output.

HINT:

Codes other than DTC B1815, B1816, B1817 and B1818 may be output at this time, but they are not related to this check.

6.	CHECK INSTRUMENT PANEL WIRE (CENTER AIRBAG SENSOR - INSTRUMENT PANEL WIRE ASSEMBLY)

(a) Restore the released activation prevention mechanism of connector B to its original condition.

(b) Disconnect the instrument panel wire connector from the instrument panel wire assembly.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
Eb1-1 - Body ground	Engine switch on (IG)	Below 1 V
Eb1-2 - Body ground	Engine switch on (IG)	Below 1 V

(e) Turn the engine switch off.

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
Eb1-1 - Eb1-2	Always	Below 1 Ω

(h) Release the activation prevention mechanism built into connector B .

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
Eb1-1 - Eb1-2	Always	1 MΩ or higher
Eb1-1 - Body ground	Always	1 MΩ or higher
Eb1-2 - Body ground	Always	1 MΩ or higher