POWER ASSIST SYSTEMS  POWER STEERING SYSTEM  TERMINALS OF ECU  


CHECK POWER STEERING ECU ASSEMBLY


C240518C12
1.625,2.021 2,2.25 0.375,0.229 2.271,2.021 2.646,2.25 0.375,0.229 3.375,2.021 3.75,2.25 0.375,0.229 4.833,2.021 5.208,2.25 0.375,0.229 1.698,2.052 2.177,2.375 0.479,0.323 10 false E40 2.396,2.052 2.76,2.333 0.365,0.281 10 false z7 3.5,2.052 3.75,2.333 0.25,0.281 10 false z8 4.906,2.052 5.354,2.323 0.448,0.271 10 false A25 0.219,0.094 0.375,0.271 0.156,0.177 10 false *a
*a Component without harness connected
(Power Steering ECU Assembly)
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a.

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

NOTICE:
·

Check if the power steering ECU assembly connectors are securely connected by pulling on them from the backside.

·

If the EPS warning light is illuminated due to a malfunction, the fail-safe function may cause the voltage of the power steering ECU's terminals to become 0 V.



Terminals No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
E40-1 (IG) - Body ground L - Body ground IG power source voltage Ignition switch ON 8 to 16 V
E40-2 (SPD) - A25-2 (PGND) V - W-B Vehicle speed signal Driving at approx. 20 km/h (12 mph) Pulse generation
(See waveform 1)
E40-6 (TS) - Body ground SB - Body ground Test mode signal Always 9 to 16 V
E40-7 (CANH) - E40-8 (CANL) GR - W CAN communication line Ignition switch off 54 to 69 Ω
z7-1 (TRQ2) - z7-2 (TRQG) Y - B Torque sensor 2 input signal Engine running and steering wheel not being turned (without load) 2.3 to 2.7 V
Engine running and steering wheel being turned to right with vehicle stopped 1.2 to 2.5 V
Engine running and steering wheel being turned to left with vehicle stopped 2.5 to 3.8 V
z7-2 (TRQG) - Body ground B - Body ground Torque sensor ground Always Below 1 Ω
z7-8 (TRQV) - z7-2 (TRQG) R - B Torque sensor power source Ignition switch ON 4.5 to 5.5 V
z7-9 (TRQ1) - z7-2 (TRQG) W - B Torque sensor 1 input signal Engine running and steering wheel not being turned (without load) 2.3 to 2.7 V
Engine running and steering wheel being turned to right with vehicle stopped 2.5 to 3.8 V
Engine running and steering wheel being turned to left with vehicle stopped 1.2 to 2.5 V
z8-1 (M1) - Body ground R - Body ground Power steering motor assembly output signal 1 Engine running and steering wheel being turned to right 9 to 16 V
Engine running and steering wheel being turned to left 6 to 8 V
z8-2 (M2) - Body ground B - Body ground Power steering motor assembly output signal 2 Engine running and steering wheel being turned to right 6 to 8 V
Engine running and steering wheel being turned to left 9 to 16 V
A25-1 (PIG) - Body ground L - Body ground Power steering motor assembly power supply input signal Always 9 to 16 V
A25-2 (PGND) - Body ground W-B - Body ground Power ground Always Below 1 Ω

If the result is not as specified, the ECU may have a malfunction.


b.
C296034E01
2.698,0.115 3.313,0.396 0.615,0.281 10 false 5 V/DIV. 1.229,1.99 2.927,2.167 1.698,0.177 10 false 20 ms./DIV. 2.854,1.229 3.313,1.427 0.458,0.198 10 false GND

Waveform 1 (Reference): Using an oscilloscope:

Item Condition
Tool setting 5 V/DIV., 20 ms./DIV.
Vehicle condition Driving at approx. 20 km/h (12 mph)