check engine light TOYOTA CAMRY V20 1986 Service Information

EFI SYSTEM CHECK PROCEDURE
(3S±FE)
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 kW/V minimum),
measure the voltage at each terminal of the wiring
connectors.
THROTTLE POSITION
SENSORTHROTTLE POSITION
SENSOR
THROTTLE POSITION
SENSOR
Terminals of ECU
NEUTRAL START
SWITCH
HEADLIGHT and
DEFOGGER EGR GAS TEMP.
SENSOR
WATER TEMP. SENSOR SUB±OXYGEN SENSORA/C MAGNET SWITCH
STOP LIGHT SWITCH
CHECK CONNECTORCHECK CONNECTORAIR FLOW METER
AIR FLOW METER
AIR FLOW METER STARTER SWITCH
SENSOR GROUND SENSOR GROUND ENGINE GROUND
ENGINE GROUND ENGINE GROUND
OXYGEN SENSOR
WARNING LIGHTA/C AMPLIFIER
SPEED SENSORTerminal name Terminal name Terminal name
DISTRIBUTORDISTRIBUTOR
DISTRIBUTOR
MAIN RELAYMAIN RELAY ISC VALVE
ISC VALVE INJECTORINJECTOR Symbol
BATTERY Symbol
Symbol
IGNITERECT ECUECT ECU
ECT ECU
IGNITER
ECT ECU
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±32

No trouble (ºCHECKº engine warning light off) and
engine running
Voltage at ECU Wiring Connectors (3S±FE)
Measuring plate fully closed
Intake air temp. 20°C (68°F)
Coolant temp. 80°C (1765F) Measuring plate fully open Throttle valve fully closed Throttle valve fully closed
Throttle valve open
Air conditioning ONThrottle valve open Throttle valve open
Cranking or idlingSTD voltage (V)
Terminals
3,000 rpmSee page Condition
IG SW ONIG SW ON
IG SW ON
IG
SW ONIG SW ON
IG SW ONCrankingIdling
FI±40
FI±44
FI±46FI±45FI±34
FI±43 FI±42
FI±47FI±35
FI±36
FI±37
FI±39
FI±41 No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±33

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

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

Check that there is voltage between ECU terminal W and body
ground. There is no voltage between ECU terminals W and E1.
(Idling)
Check wiring between ECU terminal E 1 and body
ground. '
Check GAUGE fuse 7.5A and ºCHECKº
engine warning light. No trouble (ºCHECKº engine warning light off)
and engine running
Check wiring between ECU terminal
W and fuse.Fuse blows again
Repair or replace.Repair or replace.
Repair or replace.
Try another ECU.STD voltage
No voltage Terminals ConditionTrouble
NO
BAD
BAD No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±64

Voltage at ECU Wiring Connectors (3S±FE)
No trouble (ºCHECKº engine warning light off) and engine running
Stop light SW 4N (Brake pedal depressed) or defogger SW ONCheck connector TE1 ± E1 not connected
Check connector TE 1 ± E 1 connectedMeasuring plate fully closed
Ex. shift position P or N rangeIntake air temp. 20°C (68°F)
Coolant temp. 80°C (1 760F) Measuring plate fully open
Shift position P or N rangeThrottle valve fully closedThrottle valve fully closed
Heater blower SW ON Air conditioning ONThrottle valve open
Throttle valve open
Throttle valve open
Cranking or idlingIG SW ONSTD voltage (V) Condition
3,000 rpm
IG SW ONIG SW ON1G SW ON
IG SW ON Terminals
IG SW ON
CrankingIdling
± EFI SYSTEMElectronic Control System (Electronic Controlled Unit(ECU))
FI±133

Voltage at ECU Wiring Connectors (2VZ±FE)
No trouble (ºCHECKº engine warning light off) and engine running
Stop light SW ON (Brake pedal depressed)Check connector TE1 ± E1 not connected
Check connector TE1 ± E1 connected
Ex. shift position P or N range Measuring plate fully closed
Intake air temp. 20°C (68°F)
Coolant temp. 80°C (176°F) Measuring plate fully open
Shift position P or N range Throttle valve fully closed
Heater blower SW ON Air conditioning ON Throttle valve open Throttle valve open
Cranking or idlingSm voltage (V)
3,000 rpm IG SW ON
IG SW ON
IG SW ON
IG SW ON
IG SW ON 1G SW ON Terminals
Cranking Idling
± EFI SYSTEMElectronic Control System (Electronic Controlled Unit(ECU))
FI±134

(e) Disconnect the vacuum hose from port R of the EGR
vacuum modulator and connect port R directly to the in-
take manifold with another hose.
(d) Check that the vacuum gauge indicates high vacuum at
2,500 rpm.
HINT: As large amount of EGR gas enters, the engine will
misfire slightly.
(e) Remove the vacuum gauge and reconnect the vacuum
hoses to the proper locations. 2. PREPARATION
Using a 3±way connector, connect a vacuum gauge to the
hose between the EGR valve and vacuum pipe.
3. CHECK SEATING OF EGR VALVE
Start the engine and check that the engine starts and runs at
idle.
5. CHECK6VSV AND EGR VACUUM MODULATOR WITH
HOT ENGINE
(a) Warm up the engine.
(b) Check that the vacuum gauge indicates low vacuum at
2,500 rpm.
INSPECTION OF EGR SYSTEM
1. CHECK AND CLEAN FILTERS IN EGR VACUUM
MODULATOR
(a) Check the filters for contamination or damage.
(b) Using compressed air, clean the filters
4. CHECK6VSV WITH COLD ENGINE
(a) The coolant temperature should be below 45
°C
(113° F).
(b) Check that the vacuum gauge indicates zero at 2,500
rpm.
± EMISSION CONTROL SYSTEMS (3S±FE)Exhaust Gas Recirculation (EGR) SystemEC±9

(c) Disconnect the vacuum hose from the R port of the EGR
vacuum modulator and connect the R port directly to the
intake manifold with another hose.
(d) Check that the vacuum gauge indicates high vacuum at
3,500 rpm.
HINT: As large amount of EGR gas enters, the engine will
misfire slightly.
(e) Remove the vacuum gauge and reconnect the vacuum
hoses to the proper locations.
INSPECTION OF EGR SYSTEM
1. CHECK AND CLEAN FILTERS IN EGR VACUUM
MODULATOR
(a) Check the filters for contamination or damage.
(b) Using compressed air, clean the filters.
HINT: Install the filters with the coarser surface facing the at-
mospheric side (outward).
2. PREPARATION
Using a 3±way connector, connect a vacuum gauge to the
hose between the EGR valve and vacuum pipe.
3. CHECK SEATING OF EGR VALVE
Start the engine and check that the engine starts and runs at
idle.
4. CHECK6VSV WITH COLD ENGINE
(a) The coolant temperature should be below 40
°C
(104°F).
(b) Check that the vacuum gauge indicates zero at
2,500 rpm.
5. CHECK6VSV AND EGR VACUUM MODULATOR
WITH HOT ENGINE
(a) Warn n up the engine.
(b) Check that the vacuum gauge indicates low vacuum at 2,500
rpm.
± EMISSION CONTROL SYSTEMS (2VZ±FE)Exhaust Gas Recirculation (EGR) SystemEC±22

9. SLIGHTLY JACK UP ENGINE
Raise the engine enough to remove the weight from the en-
gine mounting on the right side.
10. REMOVE ENGINE RH MOUNTING INSULATOR
(a) (w/ A.B.S..)
Remove the clamp bolts of the PS oil cooler pipes.
(b) Remove the bolt, four nuts and mounting insulator.
11. REMOVE SPARK PLUGS (See page IG±11)
14. IF RE±USING TIMING BELT, CHECK INSTALLATION
MARKS ON TIMING BELT
Check that there are four installation marks on the timing belt
by turning the crankshaft pulley as shown in the illustration.
If the installation marks have disappeared, place a new
installation mark on .the timing belt before removing each
part.8. REMOVE ENGINE RH MOUNTING STAYS
(a) Remove the three bolts and No.1 mounting stay.
(b) Remove the bolt, nut and No.2 mounting stay.
12. REMOVE NO.2 TIMING BELT COVER
Remove the eight bolts, timing belt cover and gasket.
13. REMOVE ENGINE RH MOUNTING BRACKET
Remove the three bolts and mounting bracket.
± ENGINE MECHANICALTiming Belt (2VZ±FE)EM±35