LEXUS SC400 1991 Service Repair Manual

13. REINSTALL UPPER CONSOLE PANELFit the console panel to the console box with the four clips.
14. REINSTALL CUP HOLDER Fit the cup holder to the console box.
15. REINSTALL TRANSMISSION SHIFT LEVER KNOB (a) Slide the lever cover on the lever shaft.
(b) Install the shift lever knob with the two screws.
(c) Attach the l ever cover to the lower side of the lever knob.
16. RECONNECT CABLE TO NEGATIVE TERMINAL OF BATTERY FI±121
EFI SYSTEM
± Electronic Control System (Sub±Oxygen Sensors)
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Fuel pump ECU
COMPONENTS FOR REMOVAL AND
INSTALLATION
FI±122 ± Electronic Contro\
l System (Fuel Pump ECU)EFI SYSTEM
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INSPECTION OF FUEL PUMP ECU
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OFBATTERY
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and the negative (±) termi-
nal cable is disconnected from the battery.
2. REMOVE SEAT CUSHION AND BACK
3. REMOVE QUARTER TRIM
(a) Disconnect the rear side of the scuff plate by pulling it.
(b) Remove clip A.
(c) Remove the belt hole cover by pulling it.
(d) Remove clip B.
(e) Remove the quarter trim by pulling it.
4. DISCONNECT FUEL PUMP ECU CONNECTOR FI±123
EFI SYSTEM
± Electronic Control System (Fuel Pump ECU)
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5. INSPECT FUEL PUMP ECU(a) Connect the cable to the negative (±) terminal of thebattery.
(b) Check the connector on the wiring harness side as shown in the chart.
Check forTester connectionConditionSpecified value
ContinuityE ± Ground±Continuity
ContinuityDI ± Ground±Continuity
VoltageFP GroundSudden racing12 ± 14 VVoltageFP ± GroundIdling8 ± 10 V
Voltage+ B ± GroundIG SW ON10 ± 14 V
VoltageFPC ± Ground
Sudden racing
(1,600 rpm or more)4 ± 6 VVoltageFPC Ground
Idling2.5 V
If circuit is as specified, replace the fuel pump ECU.
(c) Disconnect the cable from the negative (±) terminal of the battery.
6. RECONNECT FUEL PUMP ECU CONNECTOR
7. INSTALL QUARTER TRIM (a) Attach the upper side of the quarter trim to the quarterpanel.
(b) Install the quarter trim with the four clips.
FI±124
EFI SYSTEM
± Electronic Control System (Fuel Pump ECU)
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(c) Install the belt hole cover with the two clips.
(d) Install the rear side of the scuff.
8. REINSTALL SEAT BACK AND CUSHION
9. RECONNECT CABLE FROM NEGATIVE TERMINAL OF BATTERY FI±125
EFI SYSTEM
± Electronic Control System (Fuel Pump ECU)
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Engine & ECT ECU
TERMINALS OF ENGINE & ECT ECU
TerminalNo.SymbolConnectionTerminalNo.SymbolConnection
E9 ± 1IGSWIgnition SwitchE9 ± 31+ BEFI Main Relay
2SPDNo. 1 Speed Sensor32+ B1EFI Main Relay
3KDKick±Down Switch33BATTBattery
4STPStop light Switch34A/CA/C Control Assembly
5±35±
6WªCHECKº Engine Warning Light36±
7RNeutral Start Switch37TRTRAC ECU
8±38NEOTRAC ECU
92Neutral Start Switch39VTO2TRAC ECU
10LNeutral Start Switch40VTO1TRAC ECU
11ADCC ECUE10 ± 1NCO T/M Input Speed Sensor
12OD1CC ECU2±
13±3SP2No. 2 Speed Sensor for ECT
14±4E11ECU Ground
15±5G2Cam position Sensor
16±6G1Cam position Sensor
17TTTDCL7NFEngine Speed Sensor
18PECT Pattern Select Switch8±
19TE2Check Connector9S2ECT Solenoid Value
20TE1Check Connector10S1ECT Solenoid Value
21D1Fuel Pump ECU11±
22FPCFuel Pump ECU12±
23ACMGA/C Magnet Clutch Relay13SLN
No.3 ECT Solenoid Valve
24M±RELEFI Main Relay14SLUNo.4 ECT Solenoid Valve
25±15±
26±16±
27±17#10No.3 and No.5 Injectors
28OD2O/D Main Relay18#20No.4 and No.6 Injectors
29±19#20No.2 and No.8 Injectors
30±20#40No.1 and No.7 Injectors
Engine & ECT ECU Terminals
FI±126 ± Electronic Control \
System (Engine & ECT ECU)EFI SYSTEM
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TERMINALS OF ENGINE & ECT ECU (Cont'd)
TerminalNo.SymbolConnectionTerminalNo.SymbolConnection
E10± 21NCOT/M Input Speed SensorE10 ± 51±
22±52HTL2LH Sub±Oxygen Sensor Heater
23SP2No.2 Speed Sensor for ECT53HTR2RH Sub±Oxygen Sensor Heater
24±54±
25G2LH (No.2) Cam Position Sensor55±
26G1RH (No.1) Cam Position Sensor56IGT2No.2 Igniter for RH Bank
27NEEngine Speed Sensor57IGT1No.1 Igniter for LH Bank
28VF2Check Connector58IGF1No.1 Igniter for LH Bank
29VF1Check Connector59IGF2No.2 Igniter for RH Bank
30±60±
31±61±
32ISC4ISC Valve62±
33ISC3ISC Valve63IDL2Sub±Throttle Position Sensor
34ISC2ISC Valve64IDL1Throttle Position Sensor
35ISC1ISC Valve65E2Sensor Ground
36* EGR4EGR Valve66KSAir Flow Meter
37* EGR3EGR Valve67OXR2
38* EGR2EGR Valve68OXL2LH Sub±Oxygen Sensor
39* EGR1EGR Valve69E1ECU Ground39* EGRVSV for EGR69E1ECU Ground
40±70±
41VCThrottle Position Sensor
Air Flow Meter71HTL1LH Main Oxygen Sensor
42VTA2Fuel Pump ECU72HTR1RH Main Oxygen Sensor
43VTA1A/C Magnet Clutch Relay73FPUVSV for Fuel Pressure Control
Value
44THWWater Temp. Sensor74* PA GVSV for EVAP
45THAIntake Air Temp. Sensor75±
46THGEGR Gas Temp. Sensor76NSWNeutral Start Switch
47OXR1RH Main Oxygen Sensor77STAStarter Relay
48OXL1LH Main Oxygen Sensor78STJCold Start Injector
49KNK2RH (No.2) Knock Sensor79E02Power Ground
50KNK1LH (No.1) Knock Sensor80E01Power Ground
Engine & ECT ECU Terminals
*USA spec. only
*  A/T only
FI±127EFI SYSTEM ± Electronic Control System (Engine & ECT ECU)
WhereEverybodyKnowsYourName

COMPONENTS FOR REMOVAL AND
INSTALLATION
INSPECTION OF ENGINE & ECT ECU
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OFBATTERY
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and the negative (±) termi-
nal cable is disconnected from the battery.
2. DISCONNECT ENGINE & ECT ECU FROM FLOOR P ANEL
(a) Remove the two clips, and pull out the instrument panel
under cover.
FI±128
EFI SYSTEM
± Electronic Control System (Engine & ECT ECU)
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(b) Take out the front side of the floor carpet.
(c) Remove the two nuts and protector.
(d) Remove the nut, and disconnect the engine & ECT ECU
from the floor panel.
3. INSPECT ENGINE & ECT ECU
A. Install SST (check harness) between engine & ECT ECU and wiring connectors
HINT:
wECU connectors are water±proof and are the bolt type.
w For water±proof type connectors, in order to measure
the voltage of ECU terminals and the resistance of
connected parts, connect a check harness (SST
09990±01000) between the ECU and wiring
connectors, then perform the inspection.
w Avoid inserting a tester probe from the other side of
connector as this noticeably reduces the water±proof
ability.
w Disconnect the ECU connectors by fully loosening the
bolt.
(a) Remove the bolt, and disconnect the two ECU
connectors.
NOTICE:
w Do not pull the wiring harness when disconnecting the
connectors.
w When disconnecting the connector, the ECU's back±up
power source is cut off, so the malfunction codes, etc.
recorded in the ECU memory are cancelled.
w Never insert a tester probe or male terminal used for
inspection purposes into the female terminal of the
vehicle wire harness. Otherwise, the female terminal may
be widened, which can reselt in faulty connection.
(b) Connect SST (check harness) between ECU and wiring
connectors.
SST 09990±01000
HINT: SST (check harness) connector terminals are ar-
ranged the same as those of the ECU. FI±129
EFI SYSTEM
± Electronic Control System (Engine & ECT ECU)
WhereEverybodyKnowsYourName

B. Inspect voltage of engine & ECT ECUCheck the voltage between each terminal.w Turn the ignition switch ON.
w Measure the voltage at each terminal.
HINT:
w Perform all voltage measurements with the connectors
connected.
w Verify that the battery voltage is 11 V or more when the
ignition switch is ON.
FI±130EFI SYSTEM ± Electronic Control System (Engine & ECT ECU)
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