Toyota Tundra 2005 Service - Repair - Maintenance page 4113

ABS (Double Cab)
System Outline
This system controls the respective brake fluid pressures acting on the disc brake cylinders of the right front wheel, left front
wheel, and rear wheels when the brakes are applied in a panic stop so that the wheels do not lock.
This results in improved directional stability and steerability during panic braking.
1. Input Signal
(1) Speed sensor signal
The speed of the wheels is detected and input to TERMINALS FL+, FR+, RL+ and RR+ of the ABS actuator with ECU.
(2) Stop light SW signal
A signal is input to TERMINAL STP of the ABS actuator with ECU when the brake pedal is depressed.
2. System Operation
During sudden braking, the ABS actuator with ECU which has signals input from each sensor lets the hydraulic pressure
acting on each wheel cylinder escape to the reservoir.
The pump inside the ABS actuator with ECU is also operating at this time and it returns the brake fluid from the reservoir to
the master cylinder, thus preventing locking of vehicle wheels.
If the ABS actuator with ECU judges that the hydraulic pressure acting on the wheel cylinder is insufficient, the current acting
on the solenoid is controlled and the hydraulic pressure is increased.
Holding of the hydraulic pressure is also controlled by the ECU, by the same method as above, by repeated pressure
reduction. Holding and increase are repeated to maintain vehicle stability and to improve steerability during sudden braking.
Service Hints
A6, A7 ABS Speed Sensor Front LH, RH
1-2 : 0.92-1.22 kΩ (20°C, 68°F)
A19 ABS Speed Sensor Rear
1-2 : 0.89-1.29 kΩ (20°C, 68°F)
3-4 : 0.89-1.29 kΩ (20°C, 68°F)
A5 ABS Actuator with ECU
46-Ground : 10-14 volts with ignition SW at ON or ST position
14-Ground : 10-14 volts with stop light SW on (Brake pedal depressed)
1-Ground : Always continuity
S4 Stop Light SW
2-1 : Closed with brake pedal depressed
: Parts Location
Code
A5 64
A6 64
A7 64
A19 70
A29 66
C12 66
: Junction Block and Wire Harness Connector
Code See Page
1D
1F 45
1H
1K 45
3A
3C
48
3E
456
See Page Code
D6
F13
J28
J29
J31
J45
Junction Block and Wire Harness (Connector Location)
Cowl Wire and Driver Side J/B (Lower Finish Panel)
Engine Room Main Wire and Driver Side J/B (Lower Finish Panel)
Cowl Wire and Sub J/B No.3 (Upper the Accelerator Pedal)
2005 TOYOTA TUNDRA (EWD611U)
See Page
67
34, 64
A 68
B 68
65
68
( )
(
Code
J47 68
J48 68
J58 68
P1 65
S4 69
)
See Page