EPS Warning Light Circuit

POWER STEERING: ELECTRONIC POWER STEERING SYSTEM: EPS Warning Light Circuit

EPS Warning Light Circuit

DESCRIPTION

If the power steering ECU detects a malfunction, the P/S (EPS) warning light comes on. At this time, the power steering ECU stores a DTC in its memory.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT CAN COMMUNICATION SYSTEM
(a) Using a 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.
2. READ VALUE USING TECHSTREAM
(a) Connect a Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Chassis / EMPS / Data List.
(e) Select the item "IG Power Supply" in the Data List and read the value displayed on the Techstream.

EMPS:





OK:
The normal condition value is displayed on the Techstream.
HINT: If the voltage is not standard value, inspect the IG power source circuit.

NG -- INSPECT POWER SOURCE CIRCUIT (IG)
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (POWER STEERING ECU - BODY GROUND)




(a) Disconnect the connectors from the power steering ECU.
(b) Measure the voltage and the resistance.
Standard:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. REPLACE POWER STEERING ECU
NOTE: After replacing the power steering ECU, perform the torque sensor zero point calibration.

NEXT -- Continue to next step.
5. CHECK PS WARNING LIGHT (COMBINATION METER)
(a) Check that the P/S warning light on the combination meter does not come on.
OK:
The P/S warning light does not come on.
NG -- REPLACE COMBINATION METER
OK -- END