relay switch TOYOTA CAMRY 2000 Service Repair Manual

3
CAMRY ± NEW FEATURES
172CM18
172CM19
ON
OFF1 sec 1 sec
1 sec 1 sec
ON
OFF1 sec 1 sec
2 sec 2 sec 2 sec53
Injector Control
1) General
Fuel clearing control and injector unsticking control have been added to the injector control.
2) Fuel Clearing Control
While the vehicle is being driven at speeds higher than 60 km / h (37.5 mph), and the ignition switch is
turned OFF after the ECM has detected a low temperature condition of less than 25C (77F) of intake
air temperature, the ECM closes the fuel shutoff valve for the delivery pipe. However, instead of immedi-
ately stopping the engine, the fuel clearing control allows the engine to stop on its own after the fuel in
the delivery pipe has been used up. If the engine is running even after 2 seconds or more have elapsed
after the ignition switch has been turned OFF, the EFI relay is turned OFF to stop the engine.
3) Injector Unsticking Control
When the ignition switch is turned ON after executing the fuel clearing control, the injector unsticking
control activates two cylinders at a time to unstick the valve that is frozen stuck onto the valve seat. At
low temperature conditions. At this time, the shutoff valve remains closed so that the injectors will not
inject fuel.
Gas Leak Judgment
If the ECM has detected a gas leak through the signals received from the pressure sensors, the ECM closes
the shutoff valves and flashes the low fuel level warning light.
These functions are canceled by resetting the ECM (by disconnecting the negative [-] terminal of the bat-
tery), which enables the engine to start.
(The ECM should be reset only after performing a gas leak check and making sure that the leak has been
eliminated.)
NOTE: The low fuel level warning light also flashes when the fuel level is extremely low. The flashing
patterns shown below differentiates a gas leak from a low fuel level.
Flashing Pattern
Gas Leak
Fuel Low Level

2. CHECK FUEL PRESSURE
(a) Check that the battery voltages is above 12 volts.
(b) Disconnect the negative (±) terminal cable from the
battery.
CAUTION: Work must be started after 90 seconds from
the time the ignition switch is turned to the ªLOCKº
position and the negative (±) terminal cable is discon±
nected from the battery.
If there is no pressure, check the following parts:
wFusible link
wFuses (AM2 30A, EFI 15A, IGN 7.5A)
wEFI main relay
wFuel pump
wWiring connections (c) Check that there is pressure in the hose from the fuel
filter.
HINT: At this time, you will hear fuel return noise.
(e) Remove the SST.
SST 09843±18020 (d) Turn the ignition switch OFF.
± 5S±FE ENGINEMFI/SFI SYSTEMEG1±178

9=4 ±01
ELECTRIC COOLING FAN COMPONENTS
INSPECTION
1. INSPECT ENGINE COOLANT TEMPERATURE
SWITCH
(a) Using an ohmmeter, check that there is no continuity
between the terminals when the engine coolant tem±
perature is above 93
C (199
F).
(b) Using an ohmmeter, check that there is continuity
between the terminals when the engine coolant tem±
perature is below 83
C (181
F).
If continuity is not as specified, replace the switch. 2. DISCONNECT ENGINE COOLANT TEMPERATURE
SWITCH CONNECTOR
Check that the cooling fan rotates.
If not, check the cooling fan relay, cooling fan, engine
main relay and fuse, and check for a short circuit
between the cooling fan relay and engine coolant
temperature switch.
3. CONNECT ENGINE COOLANT TEMPERATURE
SWITCH CONNECTOR
ON±VEHICLE INSPECTION
Low Temperature (Below 83

C (181
F))
1. TURN IGNITION SWITCH ªONº
Check that the cooling fan stops.
If not, check the cooling fan relay and engine coolant
temperature switch, and check for a separated con±
nector or severed wire between the cooling fan relay
and engine coolant temperature switch.
High Temperature (Above 93
C (199
F))
4. START ENGINE
(a) Raise engine coolant temperature to above 93
C
(199
F).
(b) Check that the cooling fan rotates.
If not, replace the engine coolant temperature switch.
± 5S±FE ENGINECOOLING SYSTEMEG1±262

*5: This indicates items for which ª2 trip detection logicº is used. With this logic, when a logic malfunction is first detected, the
malfunction is temporarily stored in the ECM memory. If the same case is detected again during the second drive test, this
second detection causes the Malfunction Indicator Lamp to light up.
The 2 trip repeats the same mode a 2nd time. (However, the IG switch must be turned OFF between the 1st trip and 2nd
trip),
In the Test Mode, the Malfunction Indicator Lamp lights up the 1st trip a malfunction is detected.wopen in EGR gas temp. sensor circuit
wShort in VSV circuit for EGR
wEGR hose disconnected, valve stuck
wClogged EGR gas passage
wECM
wThrottle position sensor IDL circuit
wAccelerator pedal and cable
wPark/Neutral Position switch circuit
wA/C switch circuit
wECM wOpen or short in starter signal circuit
wOpen or short in ignition switch or starter relay circuit ECM
wOpen or short in knock sensor circuit
wKnock sensor (looseness).
wECMMalfunction
Indicator
Lamp*

Normal
Mode Trouble AreaMemory*
Test
ModeSee page
EG1±390EG1±385
EG1±396EG1±383
N.A.N.A.
N.A.
OFFOFF
± 5S±FE ENGINEDIAGNOSTIC TROUBLE CODE CHARTEG1±307

*
: Only for California specification vehicles.
*: Except California specification vehicles with A/T.wStoplight switch
w Stoplight
w Park/neutral position switch wDefogger relay
wTaillight relay
Park/neutral position switchPark/neutral position switch
Park/neutral position switch
Malfunction indicator lampData link connector 1 and 2 Data link connector 1 and 2No.1 vehicle speed sensor
Throttle position sensor
Throttle position sensorEGR gas temp. sensor
Circuit opening relay Data link connector 1Data link connector 2
Cruise control ECUO/D main switch Terminal
No.Terminal
No.Connection
A/C amplifier
EFI main relay Sensor ground
Sensor ground
A/C amplifierEFI main relay
Knock sensorStarter relay Connection Symbol
Symbol
Battery
± 5S±FE ENGINETERMINALS OF ECMEG1±321

MATRIX CHART OF PROBLEM SYMPTOMS
When the malfunction code is not confirmed in the diagnostic trouble code check and the problem still can
not be confirmed in the basic inspection, then proceed to this step and perform troubleshooting according
to the numbered order given in the table below.
*: Except California specification vehicles.
Park/Neutral position switch circuitManifold absolute pressure sensor circuit
VSV circuit for fuel pressure control
Ignition signal circuit (Spark test)
After acceleration pedal depressed
After acceleration pedal released
Switch condition signal circuit
Muffler explosion (after fire)No initial combustion
Back up power source circuit
Hesitation/Poor accelerationNo complete combustion
ECM power source circuit
Starter and Starter relay
Engine control module
High engine idle speed
Low engine idle speedUnder normal condition
During A/C operationEngine does not crank
A/C cut control circuit Starter signal circuit
Soon after starting
Fuel system circuit
When N to D shiftIncorrect first idle
Poor
Driveability
IAC valve circuit Difficult to
start
Injector circuit
Rough idling
Does not
start
Compression
Suspect area
Cold engine
Ignition coil Engine Stall
EG R system
Hot engine
Poor Idling
Spark plug
A/T faultylG±10,30*
IG±11,30 Distributor
Symptom
ST±19,21
See page
IG±8,28* IG±6,26*
Hunting
Surging
EG1±400
EG1±410 EG1±390
EG1±403
EG1±408
EG1±415
EG1±419EG1±383EG1±372
EG1±428EG1±396
EG1 ±424
AX1±68 EG1±23
IN±36
± 5S±FE ENGINEMATRIX CHART OF PROBLEM SYMPTOMSEG1±327

CIRCUIT DESCRIPTION
When the engine is cranked, the intake air flow is slow, so fuel vaporization is poor. A rich mixture
is therefore necessary in order to achieve good startability. While the engine is being cranked, the
battery positive voltage is applied to terminal STA of the ECM. The starter signal is mainly used to
increase the fuel injection volume for the starting injection control and after±start injection control.
DIAGNOSTIC CHART
HINT: This diagnostic chart is based on the premise that the engine is cranked normally. If the
engine is not cranked, proceed to the matrix chart of problem symptoms on page EG1±327, w
Open or short in starter signal circuit.
wOpen or short in ignition switch or starter
relay circuit.
wECM
Check for open in harness and connector
between ECM and relay.Proceed to next circuit inspection
shown on matrix chart (See page
E±G±327). Diagnostic Trouble Code Detecting Condition
Repair or replace harness or
connector.
WIRING DIAGRAM
No starter signal to ECM.
Check and replace ECM.Check for the test mode.Trouble Area
DTC 43 Starter Signal Circuit
DTC No.
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±383

Setting the test mode.
(1) Turn ignition switch OFF.
(2) Connect terminals TE2 and E1 of DLC2.
(3) Turn ignition switch ON.
(Don't start the engine)
(4) Connect terminals TE1 and E1 of DLC2.
Check for open in harness and connector between engine control
module and starter relay (See page IN±31). Check output condition of diagnostic trouble code 43.
Proceed to next circuit inspection shown on
matrix chart (See page EG1±327).
Check and replace engine control module.Repair or replace harness or connector.
INSPECTION PROCEDURE
Check if code ª43º is output by the malfunc-
tion indicator lamp.
Code ª43º is output.
Start the engine.
Check if the code ª43º disappear.
Code ª43º is not output.
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±384

CIRCUIT DESCRIPTION
The Park/Neutral position switch goes on when the shift lever is in the N or P shift position. When
it goes on the terminal NSW of the ECM is grounded to body ground via the starter relay and theft
deterrent ECU, thus the terminal NSW voltage becomes 0V. When the shift lever is in the D, 2, L or
R position, the Park/Neutral position switch goes off, so the voltage of ECM terminal NSW becomes
battery voltage, the voltage of the ECM internal power source. If the shift lever is moved from the N posi-
tion to the D position, this signal is used for air±fuel ratio correction and for idle speed control (estimated
control), etc. When the Park/Neutral position switch is off, code ª51º is output in the test mode diagnosis.
(This is not abnormal.)
Park Neutral Position Switch Circuit (Only vehicles with
A±T)
Check for open in harness and connector
between park/neutral position switch and ECM.Check output condition of diagnostic trouble
code 51.
Proceed to next circuit inspection shown
on matrix chart (See age EG1±327).
Check park/neutral position switch.
(See page AX1±92) Repair or replace harness or connector.
Replace park/neutral position switch.Check and replace ECM.
Check and replace ECM.
N G Type II NGType I
DIAGNOSTIC CHART
HINT: This diagnosis chart is based on premise that the engine is cranked normally. If the engine
is not cranked, proceed to the matrix chart of problem symptoms on page EG1±327.
± 5S±FE ENGINEFE ENGINE TROUBLESHOOTING ± CIRCUITINSPECTION
EG1±400

CIRCUIT DESCRIPTION
When the ignition switch is turned on, battery positive voltage is applied to the coil, closing the
contacts of the EFI main relay and supplying power to the terminals + B and + 131 of the ECM.
Check for open in harness and connector
between IG switch and EFI main relay, EFI main
relay and body ground.
Check for open in harness and connector
between EFI main relay and battery, EFI main
relay and ECM.Check continuity between terminal E1 and
body ground.Proceed to next circuit inspection shown
on matrix chart (See page EG1±327).
Check for short in all the harness and
components connected to IGN fuse.
Check for short in all the harness and
components connected to EFI fuse.
ECM Power Source Circuit
Repair or replace harness or connector.
Repair or replace harness or connector. Check voltage of ECM power source.
DIAGNOSTIC CHART
Replace ignition switch.
Check EFI fuse.Replace EFI main relay.
Check ignition switch.Check EFI main relay.
Check IGN fuse.
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±403