The ER system is composed of there basic sub±systems: Fuel, Air Induction and Electronic Control Systems.
FUEL SYSTEM
Fuel is supplied under constant pressure to the EFI injectors by an electric fuel pump. The injectors inject a
metered quantity of fuel into the intake manifold in a accordance with signals from the ECU (Electronic Control
Unit).
AIR INDUCTION SYSTEM
The air induction system provides sufficient air for engine operation.
ELECTRONIC CONTROL SYSTEM
The Camry 3S±FE and 2V1±FE engines are equipped with a Toyota Computer Control System (TCCS) which
centrally controls the EFI, ESA, ISC, Diagnosis systems etc. by means of an Electronic Control Unit (ECU±
formerly ER computer) employing a microcomputer.
By means of the ECU, the TCCS controls the following functions:
1. Electronic Fuel Injection (EFI)
The ECU receives signals from various sensors indicating changing engine operation conditions such as:
Intake air volume
Intake air temperature
Coolant temperature
Engine rpm
Acceleration/deceleration
Exhaust oxygen content etc.
The signals are utilized by the ECU to determine the injection duration necessary for an optimum air±fuel ratio.
2. Electronic Spark Advance (ESA)
The ECU is programmed with data for optimum ignition timing under any and all operating conditions.
Using data provided by sensors which monitor various engine functions (rpm, coolant temperature, etc.), the
microcomputer (ECU) triggers the spark at precisely the right instant. (See IG section)
3. Idle Speed Control (ISC)
The ECU is programmed with target idling speed values to respond to different engine conditions (coolant
temperature, air conditioner ON/OFF, etc.). Sensors transmit signals to the ECU which control the flow of air
through the by±pass of the throttle valve and adjust idle speed to the target value. (See page FI±45,115
or 62, 117)
4. Diagnosis
The ECU detects any malfunctions or abnormalities in the sensor network and lights a ºCHECKº engine warn-
ing light on the instrument panel. At the same time, the trouble is identified and a diagnosis code is recorded
by the ECU. The diagnosis code can be read by the number of blinks of the ºCHECKº engine warning light
when terminals TE1 and E1 are connected. The diagnostic codes are refer to the later page.
(See page FI±25 or 27)
5. Fail±safe Function
In the event of the sensor malfunctioning, a back±up circuit will take over to provide minimal drivability, and
the ºCHECKº engine warning light.
± EFI SYSTEMSystem DescriptionFI±4
PRECAUTIONS
1. Before working the fuel system, disconnect the cable
from negative (±) terminal of the battery.
HINT: Any diagnostic code retained by the computer will be erased
when the battery terminal is removed. Therefore, if necessary, read
the diagnosis before removing the battery terminal.
2. Do not smoke or work open flame when working the fuel system.
3. Keep gasoline off rubber or leather parts.
INSPECTION PRECAUTIONS
MAINTENANCE PRECAUTIONS
1. CHECK CORRECT ENGINE TUNE±UP
(See page EM±8)
2. PRECAUTIONS WHEN CONNECTING GAUGE
(a) Use the battery as the power source for the timing light, tachome-
ter, etc.
(b) (3S±FE)
Connect the test probe of a tachometer to the service
connector of the distributor.
(c) (2VZ±FE)
Connect the test probe of a tachometer to the terminal
IG ± of the check connector.
3. IN EVENT OF ENGINE MISFIRE FOLLOWING
PRECAUTIONS SHOULD BE TAKEN
(a) Check proper connection of battery terminals, etc.
(b) Handle high±tension cords carefully.
(c) After repair work, check that the ignition coil terminals and
all other ignition system lines are reconnected securely.
(d) When cleaning the engine compartment, be especially
careful to protect the electrical system from water.
4. PRECAUTIONS WHEN HANDLING OXYGEN
SENSOR(S)
(a) Do not allow the oxygen sensor to drop or hit against an ob-
ject.
(b) Do not allow the sensor to come into contact with water.
± EFI SYSTEMPrecautionsFI±5
PRECAUTIONS
1. Before working the fuel system, disconnect the cable
from negative (±) terminal of the battery.
HINT: Any diagnostic code retained by the computer will be erased
when the battery terminal is removed. Therefore, if necessary, read
the diagnosis before removing the battery terminal.
2. Do not smoke or work open flame when working the fuel system.
3. Keep gasoline off rubber or leather parts.
INSPECTION PRECAUTIONS
MAINTENANCE PRECAUTIONS
1. CHECK CORRECT ENGINE TUNE±UP
(See page EM±8)
2. PRECAUTIONS WHEN CONNECTING GAUGE
(a) Use the battery as the power source for the timing light, tachome-
ter, etc.
(b) (3S±FE)
Connect the test probe of a tachometer to the service
connector of the distributor.
(c) (2VZ±FE)
Connect the test probe of a tachometer to the terminal
IG ± of the check connector.
3. IN EVENT OF ENGINE MISFIRE FOLLOWING
PRECAUTIONS SHOULD BE TAKEN
(a) Check proper connection of battery terminals, etc.
(b) Handle high±tension cords carefully.
(c) After repair work, check that the ignition coil terminals and
all other ignition system lines are reconnected securely.
(d) When cleaning the engine compartment, be especially
careful to protect the electrical system from water.
4. PRECAUTIONS WHEN HANDLING OXYGEN
SENSOR(S)
(a) Do not allow the oxygen sensor to drop or hit against an ob-
ject.
(b) Do not allow the sensor to come into contact with water.
± EFI SYSTEMInspection PrecautionsFI±5
1. Wiring connection
2. Power to ECU
(1) Fusible link(s)
(2) Fuse(s)
(3) ER main relay (See page FI±121)
3. Air flow meter (See page FI±104)
4. Water temp. sensor (See page FI±125)
5. Air temp. sensor (See page FI±104)
6. Injection signal circuit
(1) Injector wiring
(2) ECU (See page FI±130)
CHECK FUEL SUPPLY TO INJECTOR
1. Fuel tank
2. Fuel pressure in fuel line
(1) Short terminals +B and FP of the check connec-
tor.
(2) Fuel pressure at fuel return hose of fuel filter can
be felt. (See page FI±70)
1. ISC system
(1) Wiring connection(s)
(2) ISC valve (See page FI±116 or 118)
(3) ECU (test by substitution)
2. (3S±FE) ±
Idle speed ± Adjust (See page EM±19) 1. Fuel line leakage ± deformation
2. Fuse(s)
3. Fuel pump (See page FI±68)
4. Fuel filter
5. Fuel pressure regulator
(See page FI±86 or 88) 1. Oil filler cap
2. Oil dipstick
3. Hose connections
4. PCV hoses
5. EGR system EGR valve stays open CHECK EFI ELECTRONIC CIRCUIT USING
VOLT/OHMMETER
(See page FI±31)
CHECK DIAGNOSIS SYSTEM
Check for output of diagnosis code.
(See page FI±22)
CHECK FOR VACUUM LEAKS IN AIR
INTAKE LINE
SYMPTOM ± ENGINE OFTEN STALLS
CHECK IDLE SPEED
Standard: 700 + 50 rpmDiagnostic code(s) (See page FI±25 or 27)
OK CONTINUED FROM PAGE FI±12
OK CONTINUED ON PAGE FI±14Element ± Clean or replace
CHECK AIR FILTER
Malfunction
code(s)
Normal code
BADBAD
BAD
BADBAD
± EFI SYSTEMTroubleshootingFI±13
1. Spark plugs
2. Compression pressure
Minimum: 10.0 kg/cm 2
(142 psi, 981 kPa)
at 250 rpm
3. Valve clearance
Standard:
3F±FE IN 0.19 ± 0.29 mm
(0.007 ± 0.011 in.)
EX 0.28 ± 0.38 mm
(0.011 ± 0.015 in.)
2VZ±FE IN 0.13 ± 0.23 mm
(0.005 ± 0.009 in.)
EX 0.27± 0.37 mm
(0.011 ± 0.015 in.)
1. Wiring connection
2. Power to ECU
(1) Fusible link(s)
(2) Fuse(s)
(3) ER main relay (See page FI±121)
3. Air flow meter (See page FI±104)
4. Water temp. sensor (See page FI±125)
5. Air temp. sensor (See page FI±104j
6. Injection signal circuit
(1) Injector wiring
(2) ECU (See page FI±130) CHECK IGNITION TIMING
1. Connect terminals TE1 and E1 of the check connector.
2. Check ignition timing.
Standard: 10° BTDC @ idle
CHECK SPARK PLUGS
Standard: 1.1 mm (0.043 in.)
HINT: Check compression pressure and
valve clearance if necessary.
CHECK EFI ELECTRONIC CIRCUIT USING
VOLT/OHMMETER
(See page FI±31)1. Cold start injector (See page FI±78 or 81)
2. Cold start injector time switch
(See page FI±124)
1. Fuel pump (See page FI±68)
2. Fuel filter
3. Fuel pressure regulator
(See page FI±84 or 86) CHECK COLD START INJECTOR
(See page FI±78 or 81)
OK CONTINUED FROM PAGE FI±13
CHECK FUEL PRESSURE
(See page FI±70)Ignition timing ± Adjust
(See page IG±17 or 21)
CHECK INJECTORS
(See page FI±88 or 93)Injection condition
BADBAD
BAD BAD
± EFI SYSTEMTroubleshootingFI±14
SYMPTOM ± HIGH ENGINE IDLE SPEED (NO DROP)
HINT (3S±FE): Disconnecting the battery will cause the idling speed data in the ISC to be returned to the initial
idling speed, causing the idling speed to rise above 700 rpm. should this happen, either carry out a driving test,
including stop±go several times at a speed above 10 km/h, or start the engine, idle for 30 seconds and then turn
the engine off repeatedly. By doing this, idle data will be stored in the ISC and the idle rpm will be at specified
value.
1. Spark plugs
2. Compression pressure
Minimum: 10.0 kg/cm2
(142 psi, 981 kPa)
at 250 rpm
3. Valve clearance
Standard:
3F±FE IN 0.19 ± 0.29 mm
0.007 ± 0.011 in.)
EX 0.28 ± 0.38 mm
(0.011 ± 0.015 in.)
2VZ±FE I N 0.13 0.23 mm
(0.005 ± 0.009 in.)
EX 0.27± 0.37 m m
(0.011 0.015 in.)
1. Wiring connection
2. Power to ECU
(1) Fusible link(s)
(2) Fuse(s)
(3) ER main relay (Seepage FI±121)
3. Air flow meter (See page FI±104)
4. Water temp. sensor (See page FI±125)
5. Air temp. sensor (See page FI±104)
6. Injection signal circuit
(1) Injector wiring
(2) ECU (See page FI±I30)
7. Oxygen sensor(s)
(See page FI±129 or 131) CHECK SPARK PLUGS
Standard: 1.1 mm (0.043 in.)
HINT: Check compression pressure and valve
clearance if necessary.
CHECK EFI ELECTRONIC CIRCUIT USING
VOLT/OHMMETER
(See page FI±31 )1. Cold start injector (See page FI±78 or 81)
2. Cold start injector time switch
(See page FI±124)
t . Fuel pump (See page FI±68)
2. Fuel filter
3. Fuel pressure regulator
(See page FI±84 or 86) CHECK COLD START INJECTOR
(See page FI±78 or 81)
CHECK FUEL PRESSURE
(See page FI±70)
OK CONTINUED FROM PAGE FI±15
CHECK INJECTORS
(See page FI±88 or 93)Injection condition
BADBAD
BAD
BAD
± EFI SYSTEMTroubleshootingFI±16
1. Wiring connection
2. Power to ECU
(1) Fusible link(s)
(2) Fuse(s)
(3) ER main relay (See page FI±121)
3. Air flow meter (See page FI±104)
4. Water temp. sensor (See page FI±125)
5. Air temp. sensor (See page FI±104)
6. Injection signal circuit
(1) Injector wiring
(2) ECU (See page FI±130)CHECK EFI ELECTRONIC CIRCUIT USING
VOLT/OHMMETER
(See page FI±31)
1. Fuel pump (See page FI±68)
2. Fuel filter
3. Fuel pressure regulator
(See page FI±84 or 86) 1. Wiring connection(s) .
2. ISC valve (See page FI±116 or 118)
3. Air conditioner switch
CHECK DIAGNOSIS SYSTEM
Check for output of diagnosis code.
(See page FI±22)
CHECK THROTTLE POSITION SENSOR
(See page FI±105, 110 or 112) CHECK THROTTLE OPENER SYSTEM
(3S±FE only)
CHECK AIR CONDITIONER IDLE±UP
CIRCUIT
CHECK COLD START INJECTOR
(See page FI±78 or 81) CHECK FUEL PRESSURE
(See page FI±74)Diagnostic code(s) (See page FI±25 or 27)
Injector(s) Leakage, Injection quantityAir valve for air conditioner ± Leakage
CHECK INJECTORS
(See page FI±88 or 93) CHECK ACCELERATOR LINKAGE
CHECK ISC SYSTEMMalfunction
code(s)
Cold start injectorLinkage ± Stuck
Throttle opener
Throttle body
Normal code
BADBAD
BAD
BADBADBADBAD
BADBAD
± EFI SYSTEMTroubleshootingFI±17
1. Wiring connection
2. Power to ECU
(1) Fusible link(s)
(2) Fuse(s)
(3) ER main relay (See page FI±121)
3. Air flow meter (See page FI±104)
4. Water temp. sensor (See page FI±125)
5. Air temp. sensor (See page FI±104)
6. Injection signal circuit
(1) Injection wiring
(2) ECU (See page FI±130)
7. Oxygen sensor(s)
(Seepage FI±129 or 131)
CHECK IGNITION TIMING
1. Connect terminals TE1 and E1 of the check con-
nector.
2. Check ignition timing.
Standard: 10
° BTDC @ idle
1. Oil filler cap
2. Oil dipstick
3. Hose connections
4. PCV hoses
5. EGR system ± EGR valve stays open
CHECK EFI ELECTRONIC CIRCUIT USING
VOLT/OHMMETER
(See page FI±31)
1. Cold start injector (See page FI±78 or 81)
2. Cold start injector time switch
(See page FI±124)
1. Fuel pump (See page FI±68)
2. Fuel filter
3. Fuel pressure regulator
(See page FI±84 or 86)
CHECK DIAGNOSIS SYSTEM
Check for output of diagnosis code.
(See page FI±22)
SYMPTOM ± ENGINE BACKFIRES± Lean Fuel Mixture
CHECK FOR VACUUM LEAKS IN AIR
INTAKE LINE
CHECK COLD START INJECTOR
(See page FI±78 or 81)
CHECK FUEL PRESSURE
(See page FI±70)
Diagnostic code(s) (See page FI±25 or 27)
Ignition timing ± Adjust
(See page IG±17 or 21)
CHECK INJECTORS
(See page FI±88 or 93)Injectors ± Clogged
Malfunction
code(s)
Normal code
BAD
BAD
BAD BAD
BAD
± EFI SYSTEMTroubleshootingFI±18