Toyota Sienna Service Manual: Steering Angle Sensor Circuit Malfunction
DTC C1231/31 Steering Angle Sensor Circuit Malfunction
DESCRIPTION
The steering angle sensor signal is sent to the skid control ECU through the CAN communication system.
When there is a malfunction in the communication, it will be detected by the
diagnosis function.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
- When U0073/94, U0100/65, U0123/62, U0124/95 or U0126/63 are output accompanied with C1231/ 31, inspect and repair the trouble areas indicated by U0073/94, U0100/65, U0123/62, U0124/95 or U0126/63 first.
- When the speed sensor or the yaw rate sensor has trouble. DTCs for the steering angle sensor may be output even when the steering angle sensor is normal. When DTCs for the speed sensor or yaw rate sensor are output accompanied with other DTCs for the steering angle sensor, inspect and repair the speed sensor and yaw rate sensor first, and the n inspect and repair the steering angle sensor.
1 INSPECT STEERING ANGLE SENSOR
(a) Remove the steering wheel and the column lower cover.
(b) Disconnect the steering angle sensor connector.
(c) Turn the ignition switch to the ON position.
(d) Measure the voltage according to the value(s) in the table below.
Standard voltage 
(e) Measure the voltage according to the value(s) in the table below.
Standard voltage 
REPLACE STEERING ANGLE SENSOR
SM Solenoid Circuit
DTC C1225/25 SM Solenoid Circuit
DESCRIPTION
This solenoid turns on when receiving signals the ECU and controls the
pressure acting on the wheel
cylinders to control the braking force.
WIRIN ...
Stuck in Deceleration Sensor
DESCRIPTION
The yaw rate sensor and deceleration sensor signal is sent to the skid
control ECU through the CAN
communication system. When there is a malfunction in the communication, it will
...
Other materials:
Ignition key cylinder light
ON-VEHICLE INSPECTION
1. KEY CYLINDER LIGHT ASSEMBLY
Connect the battery positive (+) lead to the terminal
1 and the battery negative (-) lead to the terminal 2,
and check that the indicator light comes on.
2. TRANSPONDER KEY AMPLIFIER
Inspect key cylinder light o ...
Reassembly
1. INSTALL UNDERDRIVE CLUTCH DRUM O-RING
(a) Coat a new O-ring with ATF, and install it to the
underdrive clutch drum.
NOTICE:
Make sure that the O-ring is not twisted or
pinched.
2. INSTALL UNDERDRIVE CLUTCH PISTON SET
(a) Coat the underdrive clutch piston with ATF, and
install it t ...
Other functions
Switching between outside air and recirculated air modes
Press .
The mode switches between outside air mode (
appears on the
display) and recirculated air mode (
appears on the display) each
time the button is pressed.
Defogging the windshield
Defoggers are used to defog the windshield a ...
