The passenger airbag ON/OFF indicator indicates the operation condition of the front passenger airbag assembly and the front seat side airbag assembly (passenger side).

DTC B1660/43 is recorded when a malfunction is detected in the passenger airbag ON/OFF indicator circuit.

DTC No.	DTC Detecting Condition	Trouble Area
B1660/43	The center airbag sensor assembly receives an open circuit signal, a short circuit to ground signal or a short circuit to B+ signal in the passenger airbag ON/OFF indicator circuit for 2 seconds. Passenger airbag ON/OFF indicator malfunction Center airbag sensor assembly malfunction	Instrument panel wire Clock assembly Center airbag sensor assembly

WIRING DIAGRAM

Dtc B1660/43 Passenger Airbag On / Off Indicator Circuit Malfunction. SUPPLEMENTAL RESTRAINT SYSTEM. Lexus IS250 IS220d GSE20 ALE20

INSPECTION PROCEDURE

1.CHECK PASSENGER AIRBAG ON/OFF INDICATOR CONDITION

Turn the engine switch on (IG).

Check the passenger airbag ON/OFF indicator operation.

HINT:

Refer to the normal condition of the passenger airbag ON/OFF indicator .

Dtc B1660/43 Passenger Airbag On / Off Indicator Circuit Malfunction. SUPPLEMENTAL RESTRAINT SYSTEM. Lexus IS250 IS220d GSE20 ALE20

Result:
ON/OFF Indicator Illumination Proceed to
Always ON A
OFF B

Go to step 9

A

2.CHECK CONNECTION OF CONNECTORS

Turn the engine switch off.

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

Check that the connectors are properly connected to the center airbag sensor assembly and the clock assembly.

OK:
The connectors are properly connected.

Go to step 5

OK

4.CHECK CENTER AIRBAG SENSOR ASSEMBLY

Dtc B1660/43 Passenger Airbag On / Off Indicator Circuit Malfunction. SUPPLEMENTAL RESTRAINT SYSTEM. Lexus IS250 IS220d GSE20 ALE20

Connect the connectors to the center airbag sensor assembly and the clock assembly.

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

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

Clear the DTCs stored in memory .

Turn the engine switch off.

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

Check for DTCs .

OK:
DTC B1660/43 is not output.

HINT:

Codes other than DTC B1660/43 may be output at this time, but they are not related to this check.

REPLACE CENTER AIRBAG SENSOR ASSEMBLY

USE SIMULATION METHOD TO CHECK

5.CHECK INSTRUMENT PANEL WIRE (OPEN)

Turn the engine switch off.

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

Disconnect the connector from the clock assembly.

Using a service wire, connect J47-23 (PAON) and J47-17 (P-AB) of connector "B".

NOTICE:

Do not forcibly insert a service wire into the terminals of the connector when connecting.

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

Standard resistance:
w/ Navigation system:
Tester connection Condition Specified condition
J53-3 (PAON) - J53-9 (P-AB) Always Below 1 Ω
w/o Navigation system:
Tester connection Condition Specified condition
J54-6 (PAON) - J54-7 (P-AB) Always Below 1 Ω

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

OK

6.CHECK INSTRUMENT PANEL WIRE (SHORT)

Disconnect the service wire from connector "B".

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

Standard resistance:
w/ Navigation system:
Tester connection Condition Specified condition
J53-3 (PAON) - J53-9 (P-AB) Always 1 MΩ or higher
w/o Navigation system:
Tester connection Condition Specified condition
J54-6 (PAON) - J54-7 (P-AB) Always 1 MΩ or higher

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

OK

7.CHECK INSTRUMENT PANEL WIRE (SHORT TO GROUND)

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

Standard resistance:
w/ Navigation system:
Tester connection Condition Specified condition
J53-3 (PAON) - Body ground Always 1 MΩ or higher
J53-9 (P-AB) - Body ground Always 1 MΩ or higher
w/o Navigation system:
Tester connection Condition Specified condition
J54-6 (PAON) - Body ground Always 1 MΩ or higher
J54-7 (P-AB) - Body ground Always 1 MΩ or higher

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

OK

8.CHECK INSTRUMENT PANEL WIRE (SHORT TO B+)

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

Turn the engine switch on (IG).

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

Standard voltage:
w/ Navigation system:
Tester connection Condition Specified condition
J53-3 (PAON) - Body ground Engine switch on (IG) Below 1 V
J53-9 (P-AB) - Body ground Engine switch on (IG) Below 1 V
w/o Navigation system:
Tester connection Condition Specified condition
J54-6 (PAON) - Body ground Engine switch on (IG) Below 1 V
J54-7 (P-AB) - Body ground Engine switch on (IG) Below 1 V

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

REPLACE CLOCK ASSEMBLY

9.CHECK CONNECTION OF CONNECTORS

Turn the engine switch off.

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

Check that the connectors are properly connected to the center airbag sensor assembly and the clock assembly.

OK:
The connectors are properly connected.

CONNECT CONNECTORS

OK

10.CHECK INSTRUMENT PANEL WIRE (OPEN)

Turn the engine switch off.

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

Disconnect the connectors from the center airbag sensor assembly and the clock assembly.

Using a service wire, connect J47-23 (PAON) and J47-17 (P-AB) of connector "B".

NOTICE:

Do not forcibly insert a service wire into the terminals of the connector when connecting.

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

Standard resistance:
w/ Navigation system:
Tester connection Condition Specified condition
J53-3 (PAON) - J53-9 (P-AB) Always Below 1 Ω
w/o Navigation system:
Tester connection Condition Specified condition
J54-6 (PAON) - J54-7 (P-AB) Always Below 1 Ω

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

OK

11.CHECK INSTRUMENT PANEL WIRE (SHORT)

Disconnect the service wire from connector "B".

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

Standard resistance:
w/ Navigation system:
Tester connection Condition Specified condition
J53-3 (PAON) - J53-9 (P-AB) Always 1 MΩ or higher
w/o Navigation system:
Tester connection Condition Specified condition
J54-6 (PAON) - J54-7 (P-AB) Always 1 MΩ or higher

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

OK

12.CHECK INSTRUMENT PANEL WIRE (SHORT TO GROUND)

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

Standard resistance:
w/ Navigation system:
Tester connection Condition Specified condition
J53-3 (PAON) - Body ground Always 1 MΩ or higher
J53-9 (P-AB) - Body ground Always 1 MΩ or higher
w/o Navigation system:
Tester connection Condition Specified condition
J54-6 (PAON) - Body ground Always 1 MΩ or higher
J54-7 (P-AB) - Body ground Always 1 MΩ or higher

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

OK

13.CHECK INSTRUMENT PANEL WIRE (SHORT TO B+)

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

Turn the engine switch on (IG).

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

Standard voltage:
w/ Navigation system:
Tester connection Condition Specified condition
J53-3 (PAON) - Body ground Engine switch on (IG) Below 1 V
J53-9 (P-AB) - Body ground Engine switch on (IG) Below 1 V
w/o Navigation system:
Tester connection Condition Specified condition
J54-6 (PAON) - Body ground Engine switch on (IG) Below 1 V
J54-7 (P-AB) - Body ground Engine switch on (IG) Below 1 V

REPAIR OR REPLACE INSTRUMENT PANEL WIRE

OK

14.CHECK CLOCK ASSEMBLY (SOURCE VOLTAGE)

Connect the connectors to the center airbag sensor assembly.

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

Turn the engine switch on (IG).

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

Standard voltage:
w/ Navigation system:
Tester connection Condition Specified condition
J53-11 (IG+) -
Body ground Engine switch on (IG) 10 to 14 V
w/o Navigation system:
Tester connection Condition Specified condition
J54-4 (IG+) - Body ground Engine switch on (IG) 10 to 14 V

REPAIR OR REPLACE WIRE HARNESS (CLOCK ASSEMBLY - BATTERY) OR BATTERY

OK

15.CHECK PASSENGER AIRBAG ON / OFF INDICATOR

Turn the engine switch off.

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

Connect the connector to the clock assembly.

Disconnect the connectors from the center airbag sensor assembly.

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

Turn the engine switch on (IG).

Check the indicator according to the conditions in the table below.

Result:
Tester connection Condition Passenger airbag ON/OFF indicator
J47-23 (PAON) - Body ground Engine switch on (IG) "ON" comes on
J47-17 (P-AB) - Body ground Engine switch on (IG) "OFF" comes on

REPLACE CLOCK ASSEMBLY

OK

16.CHECK CENTER AIRBAG SENSOR ASSEMBLY

Turn the engine switch off.

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

Connect the connectors to the center airbag sensor assembly.

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

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

Clear the DTCs stored in memory .

Turn the engine switch off.

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

Check for DTCs .

OK:
DTC B1660/43 is not output.

HINT:

Codes other than DTC B1660/43 may be output at this time, but they are not related to this check.

REPLACE CENTER AIRBAG SENSOR ASSEMBLY

USE SIMULATION METHOD TO CHECK

LEXUS IS250, IS220d / GSE20 ALE20

SUPPLEMENTAL RESTRAINT SYSTEM

Lexus IS250 IS220d GSE20 ALE20

AIRBAG SYSTEM

ON/OFF Indicator Illumination	Proceed to
Always ON	A
OFF	B

Tester connection	Condition	Specified condition
J53-3 (PAON) - J53-9 (P-AB)	Always	Below 1 Ω

Tester connection	Condition	Specified condition
J54-6 (PAON) - J54-7 (P-AB)	Always	Below 1 Ω

Tester connection	Condition	Specified condition
J53-3 (PAON) - J53-9 (P-AB)	Always	1 MΩ or higher