Refer to "56.Steering Control 6A.Troubleshooting diagnostic system check-electric power steering controls".
1) Connect the scan tool.
2) Start the engine.
3) Observe the DTC information with a scan tool. Is a DTC set?
Yes
No
Go to Intermittent conditions of electric power steering control system.
Refer to "207.Steering 20D.Symptom intermittent conditions of electric power steering control system".
1) Observe the DTC information for the EHCU with a scan tool. Is a steering angle sensor-related DTC set?
Yes
Go to the applicable DTC diagnosis.
No
=>Go to Steering angle sensor voltage inspection.
1) Turn OFF the ignition switch.
2) Disconnect the steering angle sensor harness connector (B33).
3) Turn ON the ignition switch.
4) Measure the voltage of the steering angle sensor (pins 4 and 1 of B33) with a DMM. Is the voltage within the specified range?
Value: 10 to 16 V
Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 with DPD))" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 without DPD, RZ4E))" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to Chassis CAN communication circuit inspection.
No
Repair the circuit as necessary.
1) Inspect the CAN Low circuit and CAN High circuit between the EPS motor control unit (pins 4 and 5 of C116) and the steering angle sensor (pins 2 and 3 of B33) for the following. Is the result normal?
Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 with DPD))" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 without DPD, RZ4E))" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to Inspection of steering angle sensor harness connector.
No
Repair the circuit as necessary.
1) Inspect for poor connections at the steering angle sensor harness connector (pins 2 and 3 of B33). Is the connection status normal?
Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 with DPD))" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 without DPD, RZ4E))" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to EPS motor control unit harness connector inspection.
No
Repair the connections as necessary.
1) Inspect for poor connections at the EPS motor control unit harness connector (pins 4 and 5 of C116). Is the connection status normal?
Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 with DPD))" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 without DPD, RZ4E))" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
Replace the steering angle sensor.
Note
Refer to "6.Steering 6Z.Steering Electrical Control steering angle sensor removal".
Refer to "6.Steering 6Z.Steering Electrical Control steering angle sensor installation".
Refer to "6.Steering 6Z.Steering Electrical Control steering angle sensor setting".
=>Go to Current DTC follow-up check.
No
Repair the connections as necessary.
1) Securely connect the disconnected harness connectors.
2) Clear the DTC with a scan tool.
3) Turn OFF the ignition switch for 30 seconds or more.
4) Turn ON the ignition switch.
5) Observe the DTC information with a scan tool. Is a DTC set?
Yes
=>Go to EPS motor control unit replacement.
No
Note
Refer to "6.Steering 6B.Power Assisted System power steering unit removal".
Refer to "6.Steering 6B.Power Assisted System power steering unit disassembly".
Refer to "6.Steering 6B.Power Assisted System power steering unit reassembly".
Refer to "6.Steering 6B.Power Assisted System power steering unit installation".
Refer to "6.Steering 6B.Power Assisted System power steering unit setting".
Procedure completion
1) Securely connect the disconnected harness connectors.
2) Clear the DTC with a scan tool.
3) Turn OFF the ignition switch for 30 seconds or more.
4) Turn ON the ignition switch.
5) Observe the DTC information with a scan tool.