Electronic Power Steering System

POWER STEERING: ELECTRONIC POWER STEERING SYSTEM: IG Power Source Circuit

IG Power Source Circuit

DESCRIPTION

The troubleshooting procedure for a situation in which no DTCs are output but the P/S warning light is always on is specified here. The P/S warning light remains on when there is an open in the IG circuit inputting power source voltage to the power steering ECU assembly.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK HARNESS AND CONNECTOR
(a) Check the indication condition of the P/S warning light while by wiggling the power steering ECU assembly connector and wire harness up and down, and right and left.
OK:
P/S warning light indication condition does not change.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
2. INSPECT CAN COMMUNICATION SYSTEM
(a) Using the Techstream, check for DTCs and confirm that there are no problems in the CAN communication system.
OK:
DTCs are not output.
NG -- GO TO CAN COMMUNICATION SYSTEM
OK -- Continue to next step.
3. INSPECT MULTIPLEX COMMUNICATION SYSTEM (BEAN)
(a) Using the Techstream, check for DTCs and confirm that there are no problems in the multiplex communication system (BEAN).
OK:
DTCs are not output.
NG -- GO TO MULTIPLEX COMMUNICATION SYSTEM (BEAN)
OK -- Continue to next step.
4. INSPECT FUSE (ECU-IG LH)
(a) Remove the ECU-IG LH fuse from the cowl side J/B LH.
(b) Check for continuity of the ECU-IG LH fuse.
OK:
Continuity
NG -- REPLACE FUSE
OK -- Continue to next step.
5. INSPECT POWER STEERING ECU ASSEMBLY
(a) Disconnect the A23 connector from the power steering ECU assembly.





(b) Measure the voltage according to the value(s) in the table below.
Voltage:






OK -- REPLACE POWER STEERING ECU ASSEMBLY
NG -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (POWER STEERING ECU ASSEMBLY - BODY GROUND)





(a) Measure the resistance according to the value(s) in the table below.
Resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER STEERING ECU ASSEMBLY - BATTERY)
7. REPLACE POWER STEERING ECU ASSEMBLY
NOTICE:
If replacing the power steering ECU assembly, initialize the rotation angle sensor and calibrate the torque sensor zero point Electronic Power Steering System.

NEXT -- Continue to next step.
8. CHECK P/S WARNING LIGHT
(a) Check the P/S warning light status on the combination meter.
Standard:
The P/S warning light is off.
OK -- END
NG -- REPLACE PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE