Toyota Sienna Service Manual: ABS Warning Light Remains ON
DESCRIPTION
If any of the following is detected, the ABS warning light remains on.
- The skid control ECU connectors are disconnected from the skid control ECU.
- There is a malfunction in the skid control ECU internal circuit.
- There is an open in the harness between the combination meter and the skid control ECU.
HINT: In some cases, the intelligent tester cannot be used when the skid control ECU is abnormal.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 INSPECT SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED
(a) Check the skid control ECU connector's connecting condition.
OK: The connector should be securely connected.
2 INSPECT BATTERY
(a) Check the battery voltage.
Standard voltage: 11 to 14 V
2 INSPECT BATTERY
(a) Check the battery voltage.
Standard voltage: 11 to 14 V
3 INSPECT SKID CONTROL ECU (IG1 TERMINAL VOLTAGE)
(a) Disconnect the skid control ECU connector.
(b) Turn the ignition switch to the ON position.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage 
4 INSPECT SKID CONTROL ECU (GND TERMINAL CONTINUITY)
(a) Turn the ignition switch off.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance
5 CHECK HARNESS AND CONNECTOR (BETWEEN SKID CONTROL ECU AND COMBINATION METER ASSEMBLY)
(a) Disconnect the combination meter connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance 
6 INSPECT COMBINATION METER ASSEMBLY
(a) Check the combination meter (See page ME-4).
HINT: If troubleshooting has been carried out according to the PROBLEM SYMPTOMS TABLE, refer back to the table and proceed to the next step before replacing the part (See page BC-7).
REPLACE BRAKE ACTUATOR ASSEMBLY
Open in Pump Motor Circuit
DTC C1251/51 Open in Pump Motor Circuit
DESCRIPTION
The motor relay (semiconductor relay) is housed in the brake actuator
assembly and drives the pump
motor based on a signal from the skid contro ...
ABS Warning Light does not Come ON
WIRING DIAGRAM
See page BC-47.
INSPECTION PROCEDURE
1 INSPECT ABS WARNING LIGHT
(a) Disconnect the skid control ECU connector.
(b) Turn the ignition switch to the ON position.
(c) Check that ...
Other materials:
Brake fluid
Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN”
lines on the tank.
“MAX” line
“MIN” line
Adding fluid
Lift the cover off.
Make sure to check the fluid type and prepare the necessary item.
Brake fluid can absorb moisture from t ...
Sound Signal Circuit between Radio Receiver and Stereo Component
Amplifier
DESCRIPTION
The radio receiver sends a sound signal to the stereo component amplifier
through this circuit.
The sound signal that has been sent is amplified by the stereo component
amplifier, and then is sent to
the speakers.
If there is an open or short in the circuit, sound cannot be h ...
Opening the back door from outside the vehicle
Back door opener
Raise the back door while
pressing the back door opener
to release the lock to open the
back door.
Wireless remote control (vehicles with power back door)
Press and hold the switch to open/close the power back door
Vehicles without a smart key
system
Vehicl ...
