Toyota 4Runner: Airbag Signal Malfunction/Not Input (B15C4)

Toyota 4Runner Service Manual / Audio / Visual / Telematics / Cellular Communication / Safety Connect System / Airbag Signal Malfunction/Not Input (B15C4)

DESCRIPTION

If the DCM (Telematics Transceiver) detects an error in the communication between the DCM (Telematics Transceiver) and center airbag sensor assembly as a result of the DCM (Telematics Transceiver) self check, this DTC will be set.

DTC Code	DTC Detection Condition	Trouble Area
B15C4	The DCM (Telematics Transceiver) detects an error in the signals from the center airbag sensor assembly when the ignition switch is ON.	Airbag system Harness or connector Center airbag sensor assembly DCM (Telematics Transceiver)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

components such as airbags. Before servicing (including removal or installation of parts), be sure to read the Precaution in the SRS (See page )

PROCEDURE

1.	CHECK FOR DTC (AIRBAG SYSTEM)

(a) Turn the ignition switch off.

(b) Connect the Techstream to the DLC3.

(d) Check the DTC of "AIRBAG SYSTEM" (See page
).

Result

Result	Proceed to
DTC B15C4 is not output	A
DTC B15C4 is output	B

GO TO AIRBAG SYSTEM

2.	CHECK DCM (TELEMATICS TRANSCEIVER) (GSW SIGNAL)

(a) Remove the DCM (Telematics Transceiver) with the connectors connected (See page ).

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

Waveform

Item	Content
Tester connection	F39-24 (GSW) - Body ground
Tool setting	5.0 V/DIV., 20 ms/DIV.
Vehicle condition	Ignition switch ON

Text in Illustration

*a	Component with harness connected (DCM [Telematics Transceiver])

Result

Result	Proceed to
Higher than A	A
Below A	B
A	C

GO TO STEP 4

GO TO STEP 5

3.	CHECK HARNESS AND CONNECTOR (FOR OPEN CIRCUIT)

(a) Remove the center airbag sensor assembly with the connectors connected (See page ).

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
F33-24 (GSW3) - Body ground	Ignition switch ON	8.5 V or higher

Waveform

Item	Content
Tester connection	F33-24 (GSW3) - Body ground
Tool setting	5.0 V/DIV., 20 ms/DIV.
Vehicle condition	Ignition switch ON

Text in Illustration

*a	Component with harness connected (Center Airbag Sensor Assembly)

REPLACE CENTER AIRBAG SENSOR ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.	CHECK HARNESS AND CONNECTOR (FOR SHORT CIRCUIT)

(a) Disconnect the F39 DCM (Telematics Transceiver) connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
F39-24 (GSW) - Body ground	Always	10 kΩ or higher

Text in Illustration

*a	Front view of wire harness connector (to DCM [Telematics Transceiver])

GO TO STEP 6

5.	REPLACE DCM (TELEMATICS TRANSCEIVER)

(a) Replace the DCM (Telematics Transceiver) (See page ).

NOTICE:

The ignition switch must be off.
Do not replace the DCM (Telematics Transceiver) with one from another vehicle.

PERFORM DCM ACTIVATION

6.	CHECK HARNESS AND CONNECTOR (DCM - CENTER AIRBAG SENSOR ASSEMBLY)

(a) Disconnect the F39 DCM (Telematics Transceiver) connector.

(b) Disconnect the F33 center airbag sensor connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
F39-24 (GSW) - F33-24 (GSW3)	Always	Below 1 Ω
F39-24 (GSW) - Body ground	Always	10 kΩ or higher

Text in Illustration

Front view of wire harness connector

(to DCM [Telematics Transceiver])

Front view of wire harness connector

(to Center Airbag Sensor Assembly)

REPLACE CENTER AIRBAG SENSOR ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

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