Toyota 4Runner: Manual (SOS) Switch Green Indicator Malfunction (B1571)

DESCRIPTION

This DTC is stored when the DCM (Telematics Transceiver) detects an open or short in the manual (SOS) switch green indicator circuit of the manual (SOS) switch. The manual (SOS) switch green indicator illuminates after the ignition switch is turned to ON.

If the Safety Connect is not active, the manual (SOS) switch green indicator will turn off.

If the Safety Connect is active, the manual (SOS) switch green indicator will blink while in communication with the call center.

DTC Code	DTC Detection Condition	Trouble Area
B1571	Current for the manual (SOS) switch green indicator reaches the malfunction criteria for 10 seconds when the ignition switch is ON.	Map light assembly Harness or connector DCM (Telematics Transceiver)

WIRING DIAGRAM

PROCEDURE

1.	CHECK FOR DTC

(a) Turn the ignition switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON and wait for 10 seconds.

(d) Perform "Health Check" and check for current DTCs (See page ).

Result

Result	Proceed to
DTC B1570 and B1571 are output	A
DTC B1571 is output (DTC B1570 is not output)	B

B

GO TO STEP 5

A

2.	CHECK HARNESS AND CONNECTOR (DCM - MAP LIGHT ASSEMBLY)

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

(b) Disconnect the U2 map light assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
F39-11 (IND1) - U2-19 (IND1)	Always	Below 1 Ω
F39-12 (IND2) - U2-18 (IND2)	Always	Below 1 Ω
F39-26 (SIG-) - U2-16 (GND)	Always	Below 1 Ω
F39-11 (IND1) - Body ground	Always	10 kΩ or higher
F39-12 (IND2) - Body ground	Always	10 kΩ or higher
F39-26 (SIG-) - Body ground	Always	10 kΩ or higher

Text in Illustration

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

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.	CHECK HARNESS AND CONNECTOR (MAP LIGHT ASSEMBLY - BODY GROUND)

(a) Remove the map light assembly with the connector connected (See page ).

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
U2-16 (GND) - Body ground	Always	Below 1 Ω

Text in Illustration

*a	Component with harness connected (Map Light Assembly)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.	INSPECT MAP LIGHT ASSEMBLY (GREEN INDICATOR)

(a) Disconnect the U2 map light assembly connector.

(b) Connect 2 dry-cell batteries (1.5 V each) in series.

(c) Connect a positive (+) lead to of the battery terminal U2-18 (IND2) and a negative (-) lead to terminal U2-16 (GND) of the map light assembly connector.

(d) Check if the manual (SOS) switch green indicator comes on.

OK:

Green indicator comes on.

Text in Illustration

*a	Component without harness connected (Map Light Assembly)

NG

REPLACE MAP LIGHT ASSEMBLY

OK

5.	INSPECT MAP LIGHT ASSEMBLY (MANUAL [SOS] SWITCH GREEN INDICATOR CONDITION)

(a) Confirm the green indicator status after the ignition is turned to switch ON (See page ).

Result

Result	Proceed to
Green indicator remains off	A
Green indicator remains on	B

B

GO TO STEP 9

A

6.	CHECK MAP LIGHT ASSEMBLY (GREEN INDICATOR INPUT VOLTAGE)

(a) Remove the map light assembly with the connector connected (See page ).

(b) Set a voltmeter to the map light assembly connector terminals, connect a positive (+) lead to terminal U2-18 (IND2) and a negative (-) lead to terminal U2-16 (GND).

(c) Measure the voltage.

OK:

1.0 to 8.5 V in 2 seconds after the ignition switch is turned to ON and the red indicator has subsequently turned off.

0 V when the ignition switch is turned off.

Text in Illustration

*a	Component with harness connected (Map Light Assembly)

OK

REPLACE MAP LIGHT ASSEMBLY

NG

7.	CHECK DCM (TELEMATICS TRANSCEIVER) (GREEN INDICATOR OUTPUT VOLTAGE)

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

(b) Set a voltmeter to the DCM (Telematics Transceiver) connector terminals, connect a positive (+) lead to terminal F39-12 (IND2) and a negative (-) lead to body ground.

(c) Measure the voltage.

OK:

1.0 to 8.5 V in 2 seconds after the ignition switch is turned to ON and the red indicator has subsequently turned off.

0 V when the ignition switch is turned off.

Text in Illustration

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

OK

REPAIR OR REPLACE HARNESS OR CONNECTOR

NG

8.	CHECK HARNESS AND CONNECTOR (DCM - BODY GROUND)

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
F39-12 (IND2) - Body ground	Always	10 kΩ or higher

Text in Illustration

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

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

9.	REPLACE DCM (TELEMATICS TRANSCEIVER)

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

NEXT

PERFORM DCM ACTIVATION