1986 TOYOTA CAMRY V20 ECU

Check that there is voltage between ECU terminal +B or +B1 and body
ground. (IG SW ON)No specified voltage at ECU terminals VC or VS and E2.
(IG SW ON)
Check wiring between ECU terminal E1 and body
ground.
Check wiring between ECU and air flow
meter. Check air flow meter.
(See page FI±104) Measuring plate fully closed
Refer to No. 1.
±(See page FI±34) Measuring plate fully open
Replace air flow
meter.
Repair or replace.Repair or replace.
Try another ECU.STD voltage
BAD 3,000 rpm N o voltageIG SW ON
TerminalsCondition
Trouble
Idling
BAD
BAD
No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±39

No voltage between ECU terminals No. 10 and/or No. 20 and
E01 and/or E02. (IG SW ON)
Check that there is voltage between ECU terminal No. 10
and/or No. 20 and body ground.
Check resistance of magnetic coil in each injector.
STD resistance: Approx. 13.8 11Check wiring between ECU terminal E01 and/or
E02 and body ground.
Check wiring between ECU
terminal No. 10 and/or No. 20
and battery.Check fuse, fusible link and
ignition switch.
Repair or replace. Repair or replace.
Repair or replace. Try another ECU.
Replace injector. STD voltage
No voltage
IG SW ONCondition
TerminalsTrouble
BAD BAD
BADBAD No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±40

Check that there is voltage between ECU terminal +B or +B1 and
body ground. (IG SW 4N)
Check wiring between ECU terminal E1 and body
ground.No voltage between ECU terminals THA and E2.
(IG SW ON)Intake air temperature 20°C
(68°F)
Check wiring between ECU and air
temp. sensor. Check air temp. sensor.
(See page FI±104)Refer to No. 1.
(See page FI±34)
Replace air
flow meter.Repair or replace.
Repair or replace.
Try another ECU.STD voltage
No voltageIG SW ONCondition Terminals
Trouble
BAD
BAD BAD
No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±41

Check that there is voltage between ECU terminal +B or +131 and
body ground. (IG SW ON)
No voltage between ECU terminals THW
and E2.
(IG SW ON)
Check wiring between ECU terminal El and body
ground.
Check wiring between ECU and water
temp. sensor. Check water temp. sensor.
(See page FI± 1 Z5)Coolant temperature 8O° (176°F)
Refer to NO. 1.
(See page FI±34)
Replace water
temp. sensor.Repair or replace.
Repair or replace.
Try another ECU.STD voltage
No voltage
IG SW ON Terminals
Condition Trouble
BAD
BAD
BAD
No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±42

Check that there is voltage at STA (50) terminal of starter.
(IG SW START) STD voltage: 6 ± 14 v Check fusible link, battery, wiring, ignition
switch clutch start switch, starter relay and
neutral start switch..Check wiring between ECU terminal E1 and body
ground. No voltage between ECU terminals STA and E1.
OG SW START)
Check wiring between ignition switch
terminal ST1 and starter terminal STA (50).Check wiring between ECU terminal STA
and ignition switch terminal ST1.
Check starter
operation.
Repair or replace.
Repair or replace.Repair or replace.
Try another ECU.STD voltage
Check starter.
No voltage
Cranking
Terminals ConditionTrouble
BAD
BADBAD BAD No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±43

Check that there is voltage between ECU terminal IGT and body
ground. (idling) No voltage between ECU terminals IGT and El.
(idling)
Check wiring between ECU and
battery.Check wiring between ECU
terminal E1 and body ground.
Check fusible link and ignition
switch.
Check distributor. (See page±IG±7)
Check igniter. (See page IG±8)Repair or replace.Repair or replace.
Repair or replace.
Repair or replace. Try another ECU.Repair or
replace. STD voltage
No voltageCondition TerminalsTrouble
Idling
BAD
BADBADBADBAD No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±44

Check that there is voltage between ECU terminal +B or +B1 and
body ground. (IG SW ON) There is no voltage between ECU terminals ISC1 or ISC2 and
E1 (IG SW ON)
Check resistance between ISC valve
terminals +B and ISC1 or ISC2.
STD resistance: 16.0 ± 17.0

Check wiring between ECU and
ISC valve.Repair or replace
wiring. Refer to No. 1.
(See page FI±34)
Replace ISC valve.
Try another ECUSTD voltage
No voltage
IG SW ONCondition TerminalsTrouble
BAD
BAD No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±45

Check that there is voltage between ECU terminal W and
body ground.
Check wiring between ECU terminal El and body
ground. No voltage between ECU terminals W and E1.
(idling) No trouble (ºCHECKº engine warning light
off) and engine running
Check GAUGE fuse 7.5 A and ºCHECKº
engine warning light.
Check wiring between ECU
terminal W and fuse.Fuse blows again
BADRepair or replace.
Repair or replace. Repair or replace. Try another ECU.STD voltage
No voltageCondition
TerminalsTrouble
BAD
BAD No.
± EFI SYSTEMTroubleshooting with Volt/ OhmmeterFI±46