Inspection Procedure

WARNING: This page is about a different car, the 2009 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.

Before proceeding with the inspection, explain to the customer that the output DTC is related to temporary loss of the steering angle zero point calibration data, such as when the power source voltage drops when the battery is removed, and confirm whether this condition occurred.
When U0073/94, U0123/62, U0124/69 and/or U0126/63 is output together with C1231/31, inspect and repair the trouble areas indicated by U0073/94, U0123/62, U0124/69 and/or U0126/63 first. See DTC U0073/94 Control Module Communication Bus OFF; DTC U0100/65 Lost Communication with ECM / PCM; DTC U0114/27 Lost Communication with 4-Wheel Drive Clutch Control Module; DTC U0123/62 Lost Communication with Yaw Rate Sensor Module; DTC U0124/69 Deceleration Sensor Communication Circuit Malfunction; DTC U0126/63 Lost Communication with Steering Angle Sensor Module .
When the speed sensor or the yaw rate and deceleration 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 and deceleration sensor are output together with DTCs for the steering angle sensor, inspect and repair the speed sensor and the yaw rate and deceleration sensor first, and then inspect and repair the steering angle sensor. See DIAGNOSTIC TROUBLE CODE CHART .
When the steering angle sensor and/or yaw rate and deceleration sensor is replaced, perform zero point calibration for the applicable sensor(s). See CALIBRATION .
When replacing the VSC actuator assembly, perform zero point calibration. See CALIBRATION .

CHECK FOR DTC

Clear the DTCs. See DTC CHECK/CLEAR .
Turn the ignition switch off.
Turn the ignition switch to the ON position again and check that no CAN communication system DTCs are output.
Drive the vehicle at a speed of 36 km/h (22 mph), turn the steering wheel to the right and left and check that no speed sensor or yaw rate and deceleration sensor DTCs are output. See DTC CHECK/CLEAR .

Result

Result	Proceed to
DTCs (C1439/66 and/or C1445/66) are output	A
CAN communication system DTC is output	B
Speed sensor and/or yaw rate and deceleration sensor DTC is output	C
DTCs (C1439/66 and C1445/66) are not output	D

NOTE:

If there is a malfunction in the speed sensor or the yaw rate and deceleration sensor, an abnormal value may be output although the steering angle sensor is normal.
If the speed sensor and the yaw rate and deceleration sensor DTCs are output simultaneously, repair the sensors and inspect the steering angle sensor.
If the same DTC C1439/66 and/or C1445/66 is not output again, the DTC may have been stored due to a temporary loss of the steering angle zero calibration, such as when the power voltage drops.

B: INSPECT CAN COMMUNICATION SYSTEM

C: REPAIR CIRCUITS INDICATED BY OUTPUT DTCS. See DIAGNOSTIC TROUBLE CODE CHART .

D: CHECK FOR INTERMITTENT PROBLEMS. See ELECTRONIC CIRCUIT INSPECTION PROCEDURE .

PERFORM STEERING ANGLE SENSOR ZERO POINT CALIBRATION
1. Drive the vehicle straight ahead at 40 km/h (25 mph) or more for at least 10 seconds.
2. Check that the centered position of the steering wheel is correctly set while driving straight ahead.
  NOTE: If front wheel alignment and steering position are adjusted as a result of an off-centered position of the steering wheel, acquire yaw rate and deceleration sensor zero point again after the adjustments are completed.
  
  OK:
  
  The centered position of the steering wheel is correctly set.
  
  Go to next step.

RECONFIRM DTC

Check if the same DTC is output.

Result

Result	Proceed to
DTCs (C1439/66 and/or C1445/66) are output	A
DTCs (C1439/66 and C1445/66) are not output	B

NOTE: If the same DTC C1439/66 and/or C1445/66 is not output again, the DTC may have been stored due to a temporary loss of the steering angle zero calibration, such as when the power voltage drops.

B: END

A: GO TO NEXT STEP

REPLACE STEERING ANGLE SENSOR
1. Replace the steering angle sensor. See REMOVAL .
PERFORM STEERING ANGLE SENSOR ZERO POINT CALIBRATION
1. Drive the vehicle straight ahead at 40 km/h (25 mph) or more for at least 10 seconds.
2. Check that the centered position of the steering wheel is correctly set while driving straight ahead.
  NOTE: If front wheel alignment and steering position are adjusted as a result of an off-centered position of the steering wheel, acquire yaw rate and deceleration sensor zero point again after the adjustments are completed.
  
  OK:
  
  The centered position of the steering wheel is correctly set.
  
  GO TO NEXT STEP

RECONFIRM DTC

Clear the DTCs. See DTC CHECK/CLEAR .
Start the engine.
Drive the vehicle at a speed of 35 km/h (22 mph) or more and turn the steering wheel to the right and left.
Check if the same DTC is output.

Result

Result	Proceed to
DTCs (C1439/66 and/or C1445/66) are output	A
DTCs (C1439/66 and C1445/66) are not output	B

B: END

A: REPLACE VSC ACTUATOR ASSEMBLY. See REMOVAL .