Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Airbag Signal Malfunction/Not Input (B15C4)

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual / Audio, Visual, Telematics / Cellular Communication / Safety Connect System(for Gasoline Model) / Airbag Signal Malfunction/Not Input (B15C4)

DESCRIPTION

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

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B15C4

Airbag Signal Malfunction/Not Input

DCM (Telematics Transceiver) detects an error in signals from airbag ECU assembly when engine switch is on (IG).
  • Airbag system
  • Wire harness or connector
  • Airbag ECU assembly
  • DCM (Telematics Transceiver)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

The vehicle is equipped with an SRS (Supplemental Restraint System) which includes components such as airbags. Before servicing (including removal or installation of parts), be sure to read the Precaution in the SRS.

Click here

PROCEDURE

1.

CHECK DTC (AIRBAG SYSTEM)

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG) and wait for 10 seconds.

(d) Turn the Techstream on.

(e) Clear the DTCs.

Body Electrical > SRS Airbag > Clear DTCs

(f) Recheck for DTCs.

Body Electrical > SRS Airbag > Trouble Codes

Result

Proceed to

DTCs are not output

A

DTCs are output

B
B

GO TO AIRBAG SYSTEM

A

2.

INSPECT DCM (TELEMATICS TRANSCEIVER) (GSW SIGNAL)

(a) Remove the DCM (Telematics Transceiver) but do not disconnect the connectors.

Click here

*a

Component with harness connected

(DCM (Telematics Transceiver))

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

G9-24 (GSW) - Body ground

Engine switch on (IG)

6.5 to 8.5 V

Reference Waveform:

Item

Condition

Tester connection

G9-24 (GSW) - Body ground

Tool setting

5.0 V/DIV., 20 ms/DIV.

Vehicle condition

Engine switch on (IG)

Result

Proceed to

8.5 V or higher

A

Below 6.5 V

B

6.5 to 8.5 V

C
B

GO TO STEP 4

C

GO TO STEP 5

A

3.

CHECK HARNESS AND CONNECTOR (FOR OPEN CIRCUIT)

(a) Remove the airbag ECU assembly but do not disconnect the connectors.

Click here

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

G50-23 (GSW3) - Body ground

Engine switch on (IG)

8.5 V or higher

Reference Waveform:

Item

Condition

Tester connection

G50-23 (GSW3) - Body ground

Tool setting

5.0 V/DIV., 20 ms/DIV.

Vehicle condition

Engine switch on (IG)

*a

Component with harness connected

(Airbag ECU Assembly)
OK

REPLACE AIRBAG ECU ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.

CHECK HARNESS AND CONNECTOR (FOR SHORT CIRCUIT)

(a) Disconnect the G9 DCM (Telematics Transceiver) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

G9-24 (GSW) - Body ground

Always

10 kΩ or higher

G50-23 (GSW3) - Body ground

Always

10 kΩ or higher
NG

GO TO STEP 6

OK

5.

REPLACE DCM (TELEMATICS TRANSCEIVER)

(a) Replace the DCM (Telematics Transceiver).

Click here

NOTICE:

  • The engine switch must be off.
  • Do not swap the DCM (Telematics Transceiver) with one from another vehicle.
NEXT

PERFORM DCM ACTIVATION

6.

CHECK HARNESS AND CONNECTOR (DCM (TELEMATICS TRANSCEIVER) - AIRBAG ECU ASSEMBLY)

(a) Disconnect the G9 DCM (Telematics Transceiver) connector.

(b) Disconnect the G50 airbag ECU assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

G9-24 (GSW) - G50-23 (GSW3)

Always

Below 1 Ω

G9-24 (GSW) or G50-23 (GSW3) - Body ground

Always

10 kΩ or higher
OK

REPLACE AIRBAG ECU ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
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