Lexus SC300 / Lexus SC400. Service manual - part 661

TERMINALS OF ECU (Cont’d)

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ENGINE TROUBLESHOOTING

Terminals of ECU

STANDARD VALUE OF ECU TERMINALS

Symbols (Terminals No.)

STD Voltage (V)

Condition

BATT (A33) – E1 (B69)

10 ~ 14

Always

IGSW (A1)

IGSW (A1)

+ B (A31) – E1 (B69)

10 ~ 14

IG switch ON

+ B (A31)

+ B1 (A32)

 E1 (B69)

10   14

IG switch ON

VC (B41)–E2 (B65)

4.0 ~ 6.0

IG switch ON

Below 1 0

IG switch ON

IDL1 (B64)

E2 (B65)

Below 1.0

IG switch ON
Main or sub throttle valve fully closed.

IDL1 (B64)
IDL2 (B63)

– E2 (B65)

10

14

IG switch ON

(

)

10 ~ 14

IG switch ON
Main or sub throttle valve fully open.

0 1

1 0

IG switch ON

VTA1 (B43)

E2 (B65)

0.1 ~ 1.0

IG switch ON
Throttle valve fully closed.

VTA1 (B43)
VTA2 (B42)

– E2 (B65)

3 0

6 0

IG switch ON

(

)

3.0 ~ 6.0

IG switch ON
Throttle valve fully open.

KS (B66) – E1 (B69)

Pulse generation

(0 and 4 ~ 6)

Idling

THA (B45) – E2 (B65)

1.0 ~ 3.0

Idling, Intake air temp. 20

°

C (68

°

F).

THW (B44) – E2 (B65)

0.1 ~ 1.0

Idling, Water temp. 80

°

C (176

°

F).

STA (B77) – E1 (B69)

6.0 or more

Cranking

#10 (B20), #20 (B19)

E01 (B80)

10 ~ 14

IG switch ON

#10 (B20), #20 (B19)
#30 (B18), #40 (B17)

– E01 (B80)

Pulse generation

Idling

IGT1 (B57), IGT2 (B56) – E1 (B69)

Pulse generation

(0 and 4 ~ 6)

Idling

Below 1.0

IG switch ON

IGF1 (B58), IGF2 (B59) – E1 (B69)

Pulse generation

(0 and 4 ~ 6)

Idling

G1 (B26), G2 (B25) – G1

 (B6)

Pulse generation

(–1.0 ~ +1.0 or higher)

Idling

NE (B27) – NE

 (B7)

Pulse generation

(–0.8 ~ +0.8 or higher)

Idling

MREL (A24) – E1 (B69)

10 ~ 14

IG switch ON

4.2 ~ 6.0

Cranking, Sudden racing (6,000 rpm)

FPC (A22) – E1 (B69)

Pulse generation

(0 and 4 ~ 6)

Idling

DI (A21) – E1 (B69)

7.5 or more

Idling

FPU (B73)

E1 (B69)

10 ~ 14

IG switch ON

FPU (B73) – E1 (B69)

Below 2.0

Restarting high temp.

PAG (B74) – E1 (B69)

10 ~ 14

Idling

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ENGINE TROUBLESHOOTING

Standard Value of ECU Terminals

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STANDARD VALUE OF ECU TERMINALS (Cont’d)

Symbols (Terminals No.)

STD Voltage (V)

Condition

ISC1 (B35), ISC2 (B34)

E1 (B69)

10

14

IG switch ON

ISC1 (B35), ISC2 (B34)
ISC3 (B33), ISC4 (B32)

–E1 (B69)

10 ~ 14

IG switch ON

VF1 (B29), VF2 (B28) – E1 (B69)

1.0 ~ 4.0

Maintain engine speed at 2,500 rpm for two
minutes
after warming up then return to idling.

OXL1 (B48), OXR1 (B47) – E1 (B69)

Pulse generation

(0 ~ 1.0)

Maintain engine speed at 2,500 rpm for two
minutes
after warming up.

HTL1 (B71), HTR1 (B72)

E01 (B80)

Below 2.0

Idling

HTL1 (B71), HTR1 (B72)
HTL2 (B52), HTR2 (B53)

– E01 (B80)

10 ~ 14

IG switch ON

EGR1 (B39), EGR2 (B38)

E1 (B69)*

10

14

IG switch ON

EGR1 (B39), EGR2 (B38)
EGR3 (B37), EGR4 (B36)

– E1 (B69)*

10 ~ 14

IG switch ON

EGR (B39) – E1 (B69)

10 ~ 14

IG switch ON

KNK1 (B50), KNK2 (B49) – E1 (B69)

Pulse generation

(Frequency : 6.6 KHz)

Idling

NSW (B76)

E1 (B69)

10 ~ 14

IG switch ON
Other shift position in ”P”, ”N” ranges.

NSW (B76) – E1 (B69)

Below 1.0

IG switch ON
Shift position in ”P”, ”N” ranges.

SPD (A2)–E1 (B69)

Pulse generation

(0 and 10 ~ 14)

IG switch ON
Rotate driving wheel slowly.

TE1 (A20) – E1 (B69)

10 ~ 14

IG switch ON

TE2 (A19) – E1 (B69)

10 ~ 14

IG switch ON

W (A6) E1 (B69)

10 ~ 14

Idling

W (A6)–E1 (B69)

Below 2.0

IG switch ON

AD (A11) – E1 (B69)

10 ~ 14

Idling

ODI (A12) – E1 (B69)

4.0 ~ 6.0

IG switch ON

A/C (A34)

E1 (B69)

Bellow 2.0

A/C switch ON (At idling)

A/C (A34) – E1 (B69)

10 ~ 14

A/C switch OFF

ACMG (A23) E1 (B69)

Below 2.0

A/C switch ON (At idling)

ACMG (A23)–E1 (B69)

10 ~ 14

A/C switch OFF

TR (A37) – E1 (B69)

10 ~ 14

IG switch ON

Below 1 0

IG switch ON

VTO1 (A40)

E2 (B65)

Below 1.0

IG switch ON
Main or sub throttle valve fully closed.

VTO1 (A40)
VTO2 (A39)

– E2 (B65)

3 0

5 5

IG switch ON

(

)

3.0 ~ 5.5

IG switch ON
Main or sub throttle valve fully open.

NEO (A38) – E1 (B69)

4.0 ~ 6.0

IG switch ON

* Only for USA specification vehicles.

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ENGINE TROUBLESHOOTING

Standard Value of ECU Terminals

TR–88

TR–10

0

TR–12

2

TR–13

0

TR–13

6 TR–14

0 TR–1

1

4 TR–14

2

TR–108

TR–1

1

8

TR–12

4

TR–13

2

AC–84

ST–24

IG–24

IG–6

EM–30

A

T–66

IN–32

BE–381

IG–7

IG–9

MATRIX CHART OF PROBLEM SYMPTOMS

When the malfunction code is not confirmed in the diagnostic code check and the problem still can not be con-
firmed in the basic inspection, then proceed to this step and perform troubleshooting according to the numbered
order given in the table below.
The circuits indicated by  on the matrix chart can be inspected using the TCCS checker.

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ENGINE TROUBLESHOOTING

Martrix Chart of Problem Symptoms

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