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:
How to proceed with
troubleshooting
HINT:
Troubleshoot in accordance with the procedures on the
following pages
1 VEHICLE BROUGHT TO WORKSHOP
2 CUSTOMER PROBLEM ANALYSIS CHECK AND SYMPTOM CHECK
3 INSPECT COMMUNICATION FUNCTION OF LARGE-SCALE MULTIPLEX
COMMUNICATION SYSTEM (BEAN)
Use the intelligent tester to check for normal ...
Cooling fan motor
On-vehicle inspection
1. No. 1 Cooling fan motor
(A) check that the motor turns smoothly when the
battery is connected to the fan motor connector.
(B) measure the current while the motor is turning.
Standard current:
11.8 To 14.8 A at 20°c (68°f)
if the result is not as specified, r ...
Vehicle Speed Signal Circuit between Radio Receiver and Combination
Meter
DESCRIPTION
This circuit is necessary for the ASL (Auto Sound Leveliser) built into the
radio receiver.
Speed signals are received from the combination meter and used for the ASL.
The ASL function automatically adjusts the sound data in order to enable hearing
the clear audio sound
even ...
