Toyota Supra 1990 Manual page 242

FI-68 EFI SYSTEM - Troubleshooting with Volt/Ohmmeter (7M-GTE)
California vehicles only
Voltmeter
To EFI
ECU
ECU
ec nn Ch k Co ector
I
Main Relay
I
VF I
VF
EI
TE1
Oxygen Sensor
TEl
~
rv"'1
t - - - - - - - - -
f
,
' - - - - - - - - -
1----------
- - - - - - -
OX
I
SST
I
Oxygen Sensor
Heater
CD
FI3575
HT
E1
~
FI2678
CD
There is no voltage between ECU terminals VF and E 1.
Check that there is specified voltage between ECU terminal VF and
body ground.
NO OK
Check wiring between ECU terminal El and body ground.
OK BAD
Try another ECU.
Check for suction of air into exhaust
system.
OK
Check for air leak from air intake system.
OK
Check spark plugs.
OK
, - L - - - - - - - - - - ,
Repair or replace.
Repair air suction.
Repair air leak.
BAD
I
Repair or replace.
L--_ _ _ _ _ _ - - - '
~'~o"·
~_"'.C_
Check Connector
Check cam position sensor and ignition
system.
BAD
!
Repair or replace.
~~
Q'
Check Connector
OK
Check fuel pressure.
OK
Check injectors.
OK
Check cold start injector.
*
OK
Check air flow meter.
OK
Check operation of oxygen sensor.
BAD
Check wiring between oxygen sensor
and ECU connectors.
OK
Replace oxygen sensor.
L--_ _ _ _ _ _ - - - '
BAD
I
Repair or replace.
L - - - ' _ _ _ - ' _ - - - '
Repair or replace.
BAD
I
L....-_ _ _ _ _ ----'
Repair or replace.
Repair or replace.
System normal.
Repair wiring.
*
Rich malfunction only