Page 1065 of 2389
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
Page 1066 of 2389
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
Page 1067 of 2389
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
Page 1068 of 2389
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
Page 1069 of 2389
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
Page 1070 of 2389
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
Page 1071 of 2389
Check that there is voltage between ECU terminal A/C and body
ground.No voltage between ECU terminals A/C and El .
(Air conditioning ON)
Check wiring between ECU terminal El and body
ground.
Check wiring between amplifier and
ECU or compressor. Check that there is voltage between
amplifier terminal and body ground.Check wiring between
ECU
terminal A/C and
amplifier. Check compressor running.Air conditioning O N
Repair or replace. Repair or replace.Repair or replace.
Try another ECU.
Repair or replace. STD voltage
No voltage
Condition
TerminalsTrouble
BAD
BADBAD
BAD
No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±47
Page 1072 of 2389
Check that there is specified voltage between ECU terminal VF
and body ground.
Check for suction of air into exhaust
system.Check wiring between ECU terminal E1 and body ground.
Check wiring between oxygen sensors and
ECU connectors.There is no voltage between ECU terminals VF and E1.
Check for air leak from air intake system.
Check distributor and ignition system.
Check operation of oxygen sensors. Check cold start injector±.
Replace oxygen sensors.* Rich malfunction only Check fuel pressure.
Check air flow meter.Check spark plugs.Repair or replace.
Repair air suction.
Repair or replace.
Repair or replace. Repair or replace.
Repair or replace.
Repair or replace. Repair or replace. Try another ECU.
Check injectors.
System normal.Repair air leak.
Repair wiring. BAD
BADBADBADBAD
BADBAD
BAD BADBAD
BAD
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±48