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: RM000002O2R00IX
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: DESCRIPTION (2008 LX570)

DTC

B1820/55

Short in Side Squib RH Circuit

DTC

B1821/55

Open in Side Squib RH Circuit

DTC

B1822/55

Short to GND in Side Squib RH Circuit

DTC

B1823/55

Short to B+ in Side Squib RH Circuit

DESCRIPTION

The side squib RH circuit consists of the center airbag sensor and the front seat side airbag RH.

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

These DTCs are stored when a malfunction is detected in the side squib RH circuit.

DTC Code	DTC Detection Condition	Trouble Area
B1820/55	When one of the following conditions is met: The center airbag sensor receives a line short circuit signal 5 times in the side squib RH circuit during the primary check. A side squib RH malfunction. A center airbag sensor malfunction.	No. 2 floor wire Front seat side airbag assembly RH (Side squib RH) Center airbag sensor assembly
B1821/55	When one of the following conditions is met: The center airbag sensor receives an open circuit signal in the side squib RH circuit for 2 seconds. A side squib RH malfunction. A center airbag sensor malfunction.	No. 2 floor wire Front seat side airbag assembly RH (Side squib RH) Center airbag sensor assembly
B1822/55	When one of the following conditions is met: The center airbag sensor receives a short circuit to ground signal in the side squib RH circuit for 0.5 seconds. A side squib RH malfunction. A center airbag sensor malfunction.	No. 2 floor wire Front seat side airbag assembly RH (Side squib RH) Center airbag sensor assembly
B1823/55	When one of the following conditions is met: The center airbag sensor receives a short circuit to B+ signal in the side squib RH circuit for 0.5 seconds. A side squib RH malfunction. A center airbag sensor malfunction.	No. 2 floor wire Front seat side airbag assembly RH (Side squib RH) 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 SEAT SIDE AIRBAG RH (SIDE SQUIB RH)

(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 red wire side of SST (resistance: 2.1 Ω) to connector C.

CAUTION:

Never connect the tester to the front seat side airbag RH (side squib RH) 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 B1820, B1821, B1822 or B1823 is not output.

HINT:

Codes other than DTC B1820, B1821, B1822 and B1823 may be output at this time, but they are not related to this check.

2.	CHECK NO. 2 FLOOR WIRE (SIDE SQUIB RH CIRCUIT)

(a) Turn the engine switch off.

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

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

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

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
L15-1 (SFR+) - Body ground	Engine switch on (IG)	Below 1 V
L15-2 (SFR-) - Body ground	Engine switch on (IG)	Below 1 V

(g) Turn the engine switch off.

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
L15-1 (SFR+) - L15-2 (SFR-)	Always	Below 1 Ω

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
L15-1 (SFR+) - L15-2 (SFR-)	Always	1 MΩ or higher
L15-1 (SFR+) - Body ground	Always	1 MΩ or higher
L15-2 (SFR-) - Body ground	Always	1 MΩ or higher

3.	CHECK CENTER AIRBAG SENSOR

(a) Connect the connectors to the front seat side airbag RH 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 B1820, B1821, B1822 or B1823 is not output.

HINT:

Codes other than DTC B1820, B1821, B1822 and B1823 may be output at this time, but they are not related to this check.