wiring TOYOTA CAMRY V20 1986 Service Information

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

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

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

Check that there is voltage between ECU terminal +B or +131
and body ground. (IG SW ON)
No voltage between ECU terminals THG and
E2. (IG SW ON)
Check wiring between ECU terminal E1 and body ground.
Check EGR gas temp. sensor.
(See page FI±126)
Check wiring between ECU and
EGR gas temp. sensor.Refer to No. 1.
*(See page FI±34)
Replace EGR gas
temp. sensor.Check EGR system.Repair or replace.
Repair or replace.Repair or replace.
Try another ECU.BAD
BAD
BAD
BAD
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±49

EFI SYSTEM CHECK PROCEDURE
(2VZ±FE)
PREPARATION
(a) Disconnect the connectors from the ECU.
(b) Remove the locks as shown in the illustration so that the
tester probe(s) can easily come in.
NOTICE: Pay attention to sections ºAº and ºBº in the il-
lustration which can be easily broken.
(e) Reconnect the connectors to the ECU.
HINT:
wPerform all voltage measurements with the connectors con-
nected.
wVerify that the battery voltage is 11 V or more when the igni-
tion switch is in ºONº position.
Using a voltmeter with high impedance (10 k

/V mini±
mum), measure the voltage at each terminal of the wiring
connectors.
AIR FLOW METER
THROTTLE POSITION SENSOR
Terminals of ECU
No. 1 SPEED SENSOR (Meter side)
No. 2 SPEED SENSOR (AlT side)
THROTTLE POSITION SENSOR FUEL PRESSURE CONTROL VSV
THROTTLE POSITION SENSORCRUISE CONTROL COMPUTER
* 1 w/ ECT
*2 CALIF. only KNOCK CONTROL SENSOR PATTERN SELECT SWITCH
OXYGEN SENSOR HEATER
NEUTRAL START SWITCHEGR GAS TEMP. SENSOR INJECTOR (No. 2 and 3)INJECTOR (No. 4 and 5)
SIFT POSITION SWITCH.
ISC MOTOR NO. 3 COILINJECTOR (No. 1 and 6i
ISC MOTOR NO. 1 COIL
ISC MOTOR NO. 4 COILSIFT POSITION SWITCH ISC MOTOR NO. 2 COILWATER TEMP. SENSORSUB±OXYGEN SENSOR
SIFT POSITION SWITCH COLD START INJECTOR
EFI MAIN RELAY (COIL)
SIFT POSITION SWITCHSUB±OXYGEN SENSOR CHECK CONNECTOR
COMPUTER GROUND
CHECK CONNECTORCHECK CONNECTOR CHECK CONNECTOR
AIR TEMP. SENSORA/C COMPRESSOR
SENSOR GROUNDTerminal Name
OXYGEN SENSOROD MAIN SWITCH
STARTER SWITCHIGNITION SWITCH Terminal Name
AIR FLOW METERTerminal Name
POWER GROUND
POWER GROUND
WARNING LIGHT
EFI MAIN RELAY BRAKE SWITCH
EFt MAIN RELAY ECT SOLENOID
ECT SOLENOIDA/C AMPLIFIER
ECT SOLENOIDDISTRIBUTOR
DISTRIBUTOR DISTRIBUTOR
DISTRIBUTOR
TEMS ECU
TEMS ECU
TEMS ECU Symbol Symbol Symbol
BATTERY IGNITER
IGNITER
*2NSW
*1OD2
No. 30 No. 10
No. 20
*1PWR
*2OX2
M±REL
*1OD 1
*2CHK
*2THGIG SW
*1SP2
BATT
*1SL
*1 DG
1S1THW
*1S2
*1BK
ISC4 1SC2 ISC1
ISC3VTAOX1
ACTS TJSP1
THA
STAKNK EO2 E01
IGT
*1R A/C
EPU
1
L
IGF
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±50

No trouble (ºCHECKº engine warning light off) and
engine running
Voltage at ECU Wiring Connectors
Coolant temp. 80°C (176°F) Measuring plate fully closed
Intake air temp. 20°C (68°F) Measuring plate fully open Throttle valve fully closed
Air conditioning ONThrottle valve open Throttle valve open
Cranking or idlingSTD voltage (V)
IG SW ON
1G SW ON
IG SW ONCondition
IG SW ONIG SW ON
IG SW ON TerminalsSee page
CrankingIdling
FI±63FI±62FI±58
FI±60 FI±59FI±57
FI±65FI±64FI±52
FI±61FI±55
rpm No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±51