POWER ASSIST SYSTEMS  POWER STEERING SYSTEM  C1552  PIG Power Supply Voltage  C1554  Power Supply Relay Failure  


DESCRIPTION

If a problem occurs in the system, the power source relay circuit and the motor relay circuit are shut off to stop the power assist. The ECU must be replaced when there is a problem with the relays because the relays are built into the ECU.

DTC No. Detection Item DTC Detection Condition Trouble Area Warning Indicate Return-to-normal Condition Note
C1552 PIG Power Supply Voltage PIG power source circuit malfunction
·

EPS fuse

·

PIG power source circuit

·

Power steering ECU assembly


EPS warning light: Comes on After normal confirmation -
C1554 Power Supply Relay Failure Power source relay circuit malfunction
·

EPS fuse

·

PIG power source circuit

·

Power steering ECU assembly


EPS warning light: Comes on Ignition switch ON again -

WIRING DIAGRAM

C291007
1.135,1.313 1.896,1.792 0.76,0.479 10 false FL MAIN 1.302,2.354 2.375,2.552 1.073,0.198 10 false Battery 2.615,0.885 3.073,1.083 0.458,0.198 10 false EPS 4.594,0.75 5.052,0.948 0.458,0.198 10 false PIG 4.604,2.198 5.115,2.396 0.51,0.198 10 false PGND 4.51,3 4.969,3.198 0.458,0.198 10 false A25 4.51,3.188 6.479,3.594 1.969,0.406 10 false Power Steering ECU Assembly 4.375,0.604 4.51,0.844 0.135,0.24 10 false 1 4.385,2.042 4.521,2.281 0.135,0.24 10 false 2

CAUTION / NOTICE / HINT

NOTICE:
·

If the power steering ECU assembly has been replaced, perform assist map writing and torque sensor zero point calibration.

Click hereSteering>POWER ASSIST SYSTEMS>POWER STEERING SYSTEM>CALIBRATION

·

Inspect the fuses for circuits related to this system before performing the following procedure.



PROCEDURE

1.READ VALUE USING GTS
a.

Turn the ignition switch off.


b.

Connect the GTS to the DLC3.


c.

Turn the ignition switch to ON.


d.

Turn the GTS on.


e.

Enter the following menus: Chassis / EMPS / Data List.


f.

Select the item "PIG Power Supply" in the Data List and read the value displayed on the GTS.

Chassis > EMPS > Data List
Tester Display Measurement Item Range Normal Condition Diagnostic Note
PIG Power Supply Power source voltage to active motor Min.: 0.0000 V
Max.: 20.1531 V 		9 to 16 V Always
Chassis > EMPS > Data List
Tester Display
PIG Power Supply
50003 142 10
OK:

The normal condition value is displayed on the GTS.



Result:
Proceed to
OK
NG



OK

CHECK INTERMITTENT PROBLEMS

NG

2.CHECK HARNESS AND CONNECTOR (BATTERY - ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY)
2.CHECK HARNESS AND CONNECTOR (BATTERY - ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY)
a.
C250086
0.281,1.74 0.667,1.979 0.385,0.24 1.323,2.271 0.969,2.875 false 2.156,2.271 2.469,2.854 false 0.177,0.177 0.542,0.583 0.365,0.406 10 false *a 0.354,1.781 0.75,2.094 0.396,0.313 10 false A25 0.823,2.906 1.25,3.167 0.427,0.26 10 false PIG 2.302,2.906 2.833,3.177 0.531,0.271 10 false PGND
*a Front view of wire harness connector
(to Power Steering ECU Assembly)


Disconnect the A25 power steering ECU assembly connector.


b.

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

Standard Voltage:
Tester Connection Condition Specified Condition
A25-1 (PIG) - Body ground Always 9 to 16 V



c.

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

Standard Resistance:
Tester Connection Condition Specified Condition
A25-2 (PGND) - Body ground Always Below 1 Ω



Result:
Proceed to
OK
NG



OK

REPLACE POWER STEERING ECU ASSEMBLY

Click hereSteering>POWER ASSIST SYSTEMS>POWER STEERING ECU>REMOVAL


NG

REPAIR OR REPLACE HARNESS OR CONNECTOR