BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DESCRIPTION (2008 Sequoia)

Last Modified: 11-29-2007		1.6 C
Service Category: Brake	Section: Brake Control/Dynamic Control System
Model Year: 2008	Model: Sequoia	Doc ID: RM000001HY401BX
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DESCRIPTION (2008 Sequoia)

DTC

C1249/49

Open in Stop Light Switch Circuit

DESCRIPTION

The skid control ECU detects the brake operating conditions through a signal transmitted by the stop light switch. The skid control ECU incorporates an open circuit detection circuit.

DTC Code	DTC Detection Condition	Trouble Area
C1249/49	When one of following conditions is met: When voltage of STP2 pin is detected to be outside range of 1.4 to 2.2 V for 1 second. When stop light switch signal and stop light control relay drive signal do not match for 1.2 seconds. When pressure sensor signal indicates pressure increase, but stop light switch signal does not change. While driving at speed of 20 km/h (12 mph) or more, stop light switch is ON for more than 6 minutes. While vehicle is accelerated to higher than 40 km/h (24.9 mph) and then decelerated to less than 3 km/h (1.9 mph), stop light switch signal change from OFF to ON is not detected (4 trip detection logic).	ECU-IG1 fuse STOP fuse Stop light control relay Stop light switch Stop light switch circuit VSC actuator (skid control ECU)

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

When replacing the VSC actuator assembly, perform zero point calibration .

PROCEDURE

1.	READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

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

OK:

ON (brake pedal is depressed) appears on the screen.

2.	RECONFIRM DTC

(a) Clear the DTC .

(b) Check if the same DTC is output .

Result

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

3.	INSPECT FUSE (STOP)

(a) Remove the STOP fuse from the engine room relay block.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
STOP fuse	Always	Below 1 Ω

4.	INSPECT STOP LIGHT CONTROL RELAY (BRK NO. 1, BRK NO. 2)

(a) Remove the stop light control relays (BRK NO. 1 and BRK NO. 2) from the engine room relay block.

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

Standard Resistance:

for BRK NO. 1

Tester Connection	Switch Condition	Specified Condition
3 - 4	When battery voltage is not applied to terminals 1 and 2	Below 1 Ω
3 - 5	When battery voltage is not applied to terminals 1 and 2	10 kΩ or higher
3 - 4	When battery voltage is applied to terminals 1 and 2	10 kΩ or higher
3 - 5	When battery voltage is applied to terminals 1 and 2	Below 1 Ω

for BRK NO. 2

Tester Connection	Switch Condition	Specified Condition
3 - 4	When battery voltage is not applied to terminals 1 and 2	Below 1 Ω
3 - 4	When battery voltage is applied to terminals 1 and 2	10 kΩ or higher

5.	INSPECT STOP LIGHT SWITCH ASSEMBLY

(a) Disconnect the A4 switch connector.

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
1 - 2	Pin not pushed	Below 1 Ω
1 - 2	Pin pushed	10 kΩ or higher
3 - 4	Pin not pushed	10 kΩ or higher
3 - 4	Pin pushed	Below 1 Ω

6.	CHECK HARNESS AND CONNECTOR (BATTERY - SKID CONTROL ECU)

(a) Disconnect the A19 ECU connector.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A19-11 (STP2) - Body ground	Brake pedal depressed	8 to 14 V
A19-11 (STP2) - Body ground	Brake pedal released	Below 4.0 V
A19-41 (STP) - Body ground	Brake pedal depressed	8 to 14 V
A19-41 (STP) - Body ground	Brake pedal released	Below 4.0 V