sensor TOYOTA CAMRY V20 1986 Service Information

(w/o ECT)
IDL and PSW signals being output
simultaneously for several seconds.
(w/ ECT)
Open or short circuit in throttle posi-
tion sensor signal (VTA).
wEGR system (EGR valve,
EGR hose etc. )
wEGR gas temp. sensor circuit
wEGR gas temp. sensor
wBVSV for EG R
wBVSV for EGR circuit
wECU
wA/C switch circuit
wA/C amplifier
wThrottle position sensor circuit
wThrottle position sensor
wAccelerator pedal and cable No SPD signal for several seconds
when engine speed is between
2,500 ± 5,500 rpm and coolant
temp. is below
80°C (176°F) except when racing
the engine.
DIAGNOSTIC CODES (3S±FE) (Cont'd)
A/C signal or no IDL signal to
ECU, when engine is idling with
check Terminals TE1 and
E1 connected.wThrottle position sensor circuit
wThrottle position sensor
wECU
wVehicle speed sensor cir-
cuit
wVehicle speed sensor
wECU
EGR gas temp. below predeter-
mined level for during
EGR control.No STA signal to ECU when ve-
hicle stopped and engine running
over 800 rpm.wIG switch circuit
wIG switch
wECU Number of
Check engine
blinks
Throttle
Position
Sensor Signal
Switch
Condition
Signal Vehicle Speed
Sensor Signal
EGR
Malfunction Starter Signal
*CALIF. only Trouble area
FI±36
or
FI±37 DiagnosisSee
page Code
No.System
FI±49FI±43
± EFI SYSTEMDiagnosis SystemFI±26

(CALIF.)
wWhen air±fuel ratio feed±
back correction value or adap-
tive control value continues at
the upper (lean)
or lower (rich) limit for a certain
period of time or adaptive con-
trol value is not renewed for a
certain period of time.
wWhen feedback frequency of
air±fuel ratio feed±
back correction or adaptive
control is abnormally
high during feedback condition.
(Others)
wOxygen sensor outputs a lean
signal continuously for several
seconds during air±fuel ratio
feedback correction.
wOpen circuit in oxygen sensor
signal (OX).wWater temp. sensor
wInjector circuit
wInjector
wFuel line pressure
wAir flow meter
wAir intake system
wOxygen sensor circuits
wOxygen sensors
wIgnition system
wECU During air±fuel ratio feedback
correction, voltage output from the
main oxygen sensor does exceed a
set value on the lean side and the
rich side continuously for a certain
period.
Water temp. sensor
wInjector circuit
wInjector
wFuel line pressure
wAir flow meter
wCold start injector
wECU wMain oxygen heater circuit
wMain oxygen sensor heater
wECU wIgniter and ignition coil circuit
wIgniter and ignition coil
wECU
wIntake air temp. sensor circuit
wIntake air temp. sensor
wECU Open or short circuit in main oxygen
sensor heater signal
(HT).No NE signal to ECU when the en-
gine speed is above 1,000
rpm.wDistributor circuit
wDistributor
wStarter signal circuit
wECU
wMain oxygen sensor circuit
wMain oxygen sensor
wECU No NE or G signal to ECU
within 2 seconds after engine has
been cranked.
wWater temp. sensor circuit
wWater temp. sensor
wECU
DIAGNOSTIC CODES (2VZ±FE)
Open or short circuit in water temp.
sensor signal (THA).
Open or short circuit in intake air
temp. sensor signal (THA) This appears when none of the oth-
er codes are identified.
wDistributor circuit
wDistributor
wECU
No IGF signal to ECU FI±8
times in succession.
Intake air
Temp. Sensor
Signal
Air±fuel Ratio
Lean
Malfunction Number of
Check engine
blinks
Air±fuel Ratio
Rich
MalfunctionMain oxygen
Sensor Heater
SignalECT control program faulty.
Main oxygen
Sensor Signal
Water temp.
Sensor SignalECT Control
Signal
*CALIF. only Ignition
SignalTrouble area
RPM Signal
RPM SignalDiagnosisSee
page Code
No.System
Normal
wECU
FI±60FI±66
FI±59FI±62IG±4
± EFI SYSTEMDiagnosis SystemFI±27

wA/C switch circuit
wA/C switch
wA/C amplifier
wThrottle position sensor circuit
wThrottle position sensor
wNeutral position sensor
wNeutral start switch circuit
wNeutral start switch
wAccelerator pedal and cable
wECU wEGR valve
wEGR hose
wEGR gas temp. sensor cir-
cuit
wEGR gas temp. sensor
wBVSV for EG R
wBVSV circuit for EGR
wECU No SPI signal for 8 seconds when
engine speed in between 2,500 rpm
and 4,500 rpm and coolant temp.
is below 80°V 07609 except when
racing the engine.wNo. 1 vehicle speed sensor
(Meter side) circuit
wNo. 1 vehicle speed sensor
(Meter side)
wECU
A/C signal, or no IDL signal or no
NSW signal to ECU, with the check
terminals TE1 and
E1 shorted. Open circuit in VC signal or short
circuit between VS and
E2 when idle contacts are closed.
wThrottle position sensor cir-
cuit
wThrottle position sensor
wECU
DIAGNOSTIC CODES (2VZ±FE) (Cont'd)
Open or short circuit in throttle posi-
tion sensor signal
(VTA).
No STA signal to ECU until engine
speed reaches 800
rpm with vehicle not moving.
EGR gas temp. below predeter-
mined level during
EGR operation.wSub±oxygen sensor circuit
wSub±oxygen sensor
wECU Open or short circuit in sub±oxy-
gen sensor signal (OX2)
wIgnition switch circuit
wIgnition switch
wECU wAir flow meter circuit
wAir flow meter
wECU wAir flow meter circuit
wAir flow meter
wECU
Open or short circuit in knock sen-
sor signal (KNK).wKnock sensor circuit
wKnock sensor
wECU Open circuit i n E2 or short circuit
between VC and VS.
Knock control program faulty. Throttle
Position
Sensor Signal Number of
Check engine
blinks
Knock Sensor
Signal
Switch
Condition
SignalKnock Control
Signal Air Flow
Meter Signal
Vehicle Speed
Sensor Signal Air flow
Meter SignalSub±oxygen
Sensor Signal
EG R System
MalfunctionStarter Signal
*CALIF. only Trouble area
DiagnosisSee
page System Code
No.
wECUFI±55FI±57
FI±57
FI±67 FI±61
± EFI SYSTEMDiagnosis SystemFI±28

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

Check that there is voltage between ECU terminal + B or + B1 and body
ground. (IG SW ON) No voltage between ECU terminal 1D1. or PSW and E1.
(IG SW ON)
Check wiring between ECU terminal El and body
ground.
Check wiring between ECU and
throttle position sensor. Check throttle position sensor.
(See page FI±106)
Replace or repair throttle
position sensor. Refer to No. 1.
(See page FI±34) Throttle valve fully closedThrottle valve open
Repair or replace.
Repair or replace.
Try another ECU.STD voltage
No voltageIG SW ONCondition
TerminalsTrouble
BAD
BAD
BAD
BAD No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±36

Check that there is voltage between ECU terminal +B or +B1 and body
ground. (IG SW 4111)
Check wiring between ECU terminal El and body
ground. No voltage between ECU terminals IDL and E2.
OG SW ON) (Throttle valve open)
Check wiring between ECU and
throttle position sensor. Check throttle position sensor.
(See page FI±110)
Repair or replace throttle
position sensor.Refer to No. 1.
(See page FI±34) Throttle valve fully closed
Throttle valve fully open
Try another ECU. Throttle valve open
Repair or replace.Repair or replace.
wIDL ± E2
STD voltage
No voltage
IG SW ON
Condition Terminals Trouble
BAD
BAD
BAD
BAD
No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±37

Check that there is voltage between ECU terminal +B or +131 and
body ground. (IG SW ON)
Check that there is voltage between ECU terminal VC and E2
(IG SW ON)No specified voltage at ECU terminals VTA and E2.
(IG SW ON) No voltage between ECU terminals VC and E2.
(IG SW ON)
Check wiring between ECU and throttle
position sensor.
Check wiring between ECU and
throttle position sensor.Check throttle position sensor
(See page FI±110) Check throttle position sensor.
(See page FI±110)
Repair or replace
wiring.
Refer to NO±1.
(See page FI±34)
Refer to VC±E2
trouble section
Repair or replace.
Repair or replace. Repair or replace.
Try another ECU.
Try another ECU.
wNTA ± E2 wVC±E2
BAD
BAD
BAD
BAD
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±38

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 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