Lexus SC300 / Lexus SC400. Manual - part 689

NG

OK

OK

NG

2

Check voltage between terminal FPU of engine & ECT ECU connector and body ground.

C

OK

Hint

P

(2) Connect the Check Harness A.

(See page 

TR–30

)

(2) Turn ignition switch on.

Measure voltage between terminal FPU of engine &
ECT ECU connector and body ground.

Voltage:

10 – 14 V

Proceed to next circuit inspection shown on matrix chart
(See page 

TR–35

).

3

Check for open and short in harness and connector between engine & ECT ECU and VSV, VSV

and EFI main relay (See page 

IN–27

).

Repair or replace harness or connector

Check and replace engine & ECT ECU.

TR–144

–

ENGINE TROUBLESHOOTING

Circuit Inspection

–MEMO–

–

ENGINE TROUBLESHOOTING

Circuit Inspection

TR–145

TE1, TE2 Terminal Circuit

CIRCUIT DESCRIPTION

Terminal TE1 is located in the check connector in the engine compartment and terminals TE1 and TE2 are lo-
cated in the TDCL in the cabin. When these terminals are connected with the E1 terminal, diagnostic codes in
normal mode or test mode can be read from the ”CHECK” engine warning light on the combination meter.

DIAGNOSTIC CHART

DIAGNOSTIC CHART

HINT: If terminals TE1 and TE2 are connected with terminal E1, diagnostic code is not output or test mode is

not activated.
Even though terminal TE1 is not connected with terminal E1, the ”CHECK” engine warning light blinks.
For the above phenomenon, the likely cause is an open or short in the wire harness, or malfunction inside
the ECU.

Check continuity between terminal E1 and
body ground.

Repair or replace harness or
connector.

Check for open and short in harness and
connector between check connector TDCL
and ECU.

Check voltage of terminals TE1, TE2.

Check and replace ECU.

Repair or replace harness or
connector.

Check and replace ECU.

WIRING DIAGRAM

TR–146

–

ENGINE TROUBLESHOOTING

NG

OK

OK

NG

OK

NG

INSPECTION PROCEDURE

1

Check voltage between terminals TE1, TE2 and E1 of check connector, TDCL.

C

OK

P

Turn ignition switch on.

Measure voltage between terminals TE1, TE2 and E1
of check connector, TDCL.

Voltage:

10 – 14 V

Check and replace engine & ECT ECT.

2

Check continuity between terminal E1 of check connector, TDCL and body ground.

Repair or replace harness or connector.

3

Check for open and short in harness and connector between engine & ECT ECU and check con-

nector, TDCL (See page 

IN–27

).

Repair or replace harness or connector.

Check and replace engine & ECT ECU.

–

ENGINE TROUBLESHOOTING

Circuit Inspection

TR–147