Toyota Venza: Open in Stop Light Switch Circuit (C1249/49)

DESCRIPTION

The skid control ECU (housed in the actuator assembly) inputs the stop light switch signal and the condition of brake operation.

The skid control ECU has an open detection circuit, which outputs this DTC when detecting an open in the stop light input line or the ground line of the stop light circuit with the stop light switch off (brake pedal not depressed).

DTC Code	DTC Detection Condition	Trouble Area
C1249/49	After the ignition switch is turned to ON, the STP terminal voltage of the ECU is 40% to 67% of its supplied voltage for 3 seconds.	STOP fuse Stop light switch Stop light switch circuit Stop light control (BRK) relay Stop light control (BRK) relay circuit Brake actuator assembly (Skid control ECU)

WIRING DIAGRAM

PROCEDURE

1.	CHECK STOP LIGHT OPERATION

(a) Check that the stop lights come on when the brake pedal is depressed, and go off when the brake pedal is released.

OK:

Condition	Illumination Condition
Brake pedal depressed	ON
Brake pedal released	OFF

NG

GO TO STEP 4

OK

2.	READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Select the Data List on the Techstream (See page ).

ABS/VSC/TRAC

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Stop Light SW	Stop light switch / ON or OFF	ON: Brake pedal depressed OFF: Brake pedal released	-

(d) Check that the stop light switch display observed on the Techstream changes according to brake pedal operation.

OK:

The Techstream displays ON or OFF according to brake pedal operation.

NG

GO TO STEP 11

OK

3.	RECONFIRM DTC

(a) Turn the ignition switch off.

(b) Clear the DTCs (See page ).

(c) Start the engine.

(d) Depress the brake pedal several times to test the stop light circuit.

(e) Check if the same DTC is recorded (See page ).

Result	Proceed to
DTC (C1249/49) is not output	A
DTC (C1249/49) is output	B

HINT:

If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step (See page ).

A

CHECK FOR INTERMITTENT PROBLEMS

B

REPLACE BRAKE ACTUATOR ASSEMBLY

4.	INSPECT STOP FUSE

(a) Remove the STOP fuse from the main body ECU (driver side junction block).

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
STOP (10 A) fuse	Always	Below 1 Ω

Text in Illustration

*1	Main Body ECU (Driver Side Junction Block)
*2	STOP Fuse

NG

REPLACE STOP FUSE

OK

5.	INSPECT STOP LIGHT SWITCH (POWER SOURCE TERMINAL)

(a) Install the STOP fuse.

(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.

(c) Disconnect the stop light switch connector.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A35-2 - Body ground	Always	11 to 14 V

Text in Illustration

*1	Front view of wire harness connector (to Stop Light Switch)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

OK

6.	INSPECT STOP LIGHT SWITCH

(a) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Switch Condition Specified Condition 1 - 2 Switch pin free Below 1 Ω 1 - 2 Switch pin pushed in 10 kΩ or higher

NG

REPLACE STOP LIGHT SWITCH

OK

7.	INSPECT STOP LIGHT CONTROL (BRK) RELAY

(a) Remove the stop light control (BRK) relay.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
3 - 4	Voltage is not applied between terminals 1 and 2	Below 1 Ω

Text in Illustration

*1	Stop Light Control (BRK) Relay

NG

REPLACE STOP LIGHT CONTROL (BRK) RELAY

OK

8.	CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH - ENGINE ROOM RELAY BLOCK)

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A35-1 - Stop light control (BRK) relay terminal 4	Always	Below 1 Ω

Text in Illustration

*1	Front view of wire harness connector (to Stop Light Switch)
*2	Engine Room Relay Block
*3	Stop Light Control (BRK) Relay

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

9.	CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - ENGINE ROOM RELAY BLOCK)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

(b) Disconnect the skid control ECU connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A42-30 (STP) - Stop light control (BRK) relay terminal 3	Always	Below 1 Ω

Text in Illustration

*1	Front view of wire harness connector (to Brake Actuator (Skid Control ECU))
*2	Engine Room Relay Block
*3	Stop Light Control (BRK) Relay

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

10.	RECONFIRM DTC

(a) Clear the DTCs (See page ).

(b) Start the engine.

(c) Depress the brake pedal several times to test the stop light circuit.

(d) Check if the same DTC is recorded (See page ).

HINT:

Reinstall the relay, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

Result	Proceed to
DTC (C1249/49) is not output	A
DTC (C1249/49) is output	B

HINT:

If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step (See page ).

A

INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT)

B

REPLACE BRAKE ACTUATOR ASSEMBLY

11.	CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - ENGINE ROOM RELAY BLOCK)

(a) Turn the ignition switch off.

(b) Remove the stop light control (BRK) relay.

(c) Make sure that there is no looseness at the locking part and the connecting part of the connector.

(d) Disconnect the skid control ECU connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A42-30 (STP) - Stop light control (BRK) relay terminal 3	Always	Below 1 Ω

Text in Illustration

*1	Front view of wire harness connector (to Brake Actuator (Skid Control ECU))
*2	Engine Room Relay Block
*3	Stop Light Control (BRK) Relay

OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR