ANTI±LOCK BRAKE SYSTEM (A.B.S.)
Description
wThe A.B.S. is a brake system which controls the wheel cylinder hydraulic pressure of all four wheels during
sudden braking and braking on slippery road surfaces, preventing the wheels from locking. This A.B.S.
provides the following benefits:
(1) Enables steering round an obstacle with a greater degree of certainty even when panic braking.
(2) Enables stopping in a panic brake while keeping the effect upon stability and steerability to a mini-
mum, even on curves.
wThe function of the A.B.S. is to help maintain directional stability and vehicle steerability on most road
conditions. However, the system cannot prevent the vehicle from skidding if the cornering speed limit is
exceeded.
wThe A.B.S. has a longitudinal deceleration sensor to match braking characteristics to the full±time four±
wheel drive. (For 4WD)
wIn case a malfunction occurs, a diagnosis function and fail±safe system have been adopted for the A.B.S.
to increase serviceability.
2WD (SEDAN)
± BRAKE SYSTEMAnti±lock Brake System (A.B.S.)BR±56
Anti±lock Brake System Circuit
INSPECTION OF SYSTEM CIRCUIT
1. INSPECT SYSTEM CIRCUIT WITH CONNECTOR
CONNECTED
(a) Remove the A.B.S. computer.
(b) Using a voltmeter with high impedance (10 K
/V
minimum), measure the voltage at each terminal and
body ground.
If the circuit is not as specified, check and repair or re-
place the trouble part shown in the table above.
Ignition switch on and ºANTI LOCKº warning light goes on
Ignition switch on and ºANTI LOCKº warning light goes on
Ignition switch on and ºANTI LOCKº warning light goes onIgnition switch on and ºANTI LOCKº warning light goes on Ignition switch on and ºANTI LOCKº warning light goes on
Ignition switch on and ºANTI LOCKº warning light goes on
Check connector connectedºANTI LOCKº
warning light bulb
Check connector disconnected
Check connector,
computer Actuator, control
relays
AST ± Body groundSRR ± Body groundSRl ± Body ground SFR ± Body groundSFL ± Body ground
W ± Body ground
T ± Body ground Tester Connection
Ignition switch on Ignition switch on
Ignition switch on Ignition switch on
Ignition switch on Ignition switch on
Battery voltage Battery voltage
Battery voltage Battery voitage Battery voltage
Battery voltage Battery voltageTrouble Part
About 0 V
About 0 V About 0 V About 0 V
About 0 V
About 0 V
About 0 V ConditionVoltage
± BRAKE SYSTEMAnti±lock Brake System (A.B.S.)BR±102
2. INSPECT SYSTEM CIRCUIT WITH CONNECTOR
DISCONNECTED
(a) Disconnect the connectors from the computer, in-
spect at the wire harness side connector.
If the circuit is not as specified, check and repair or re-
place the trouble part shown in the table above.
(b) Connect the connectors, and install the comput-
er cover.
Ignition switch off and brake pedal depressed
Engine running and PKB lever returned Ignition switch off and brake pedal returned
Ignition switch on and PKB lever pulled
Parking broke switch,
level warning switchStop light switch,
stop light Voltage or
Resistance Value
Check connector,
wiring harness
Front RH speed
sensor
FrontrH speed
sensor Ts connector,
wiring harness
Rear RH speed
sensor
Rear RH speed
sensor
Rear LH speed
sensorRear LH speed
sensor Ts connector shorted
Ignition switch offIgnition switch off
Ignition switch off
Ignition switch off Ignition switch off Tester Connection
Ignition switch offIgnition switch off
Ignition switch off
Ignition switch off Ignition switch off Ignition switch off
Ignition switch offIgnition switch off
Ignition switch onBattery voltage
No continuity
Battery voltage
0.85 ± 1.30 k fl
0.85± 1.30k Battery voltage
Wiring harnessWiring harness
Wiring harness Battery voltage
0.85 ± 1.50 k 0.85 ± 1.50 k
No continuityNo continuity
No continuityNo continuityNo continuityTrouble Part
65±100
ECU±IG fuse Chrak Item
50±80
About 6 ContinuityResistance
Resistance
About 5 ResistanceAbout 6 0
Resistance
ResistanceAbout 6
ResistanceContinuity Resistance
Resistance
ResistanceContinuity
ResistanceAbout 6
ResistanceContinuity
Continuity
Continuity
ContinuityContinuity Continuity
Continuity Continuity
About 0 v
Continuity Continuity
Continuity
Continuity
FOG fuse Condition
ActuatorActuator
Actuator Voltage
VoltageVortege
Actuator Voltage
± BRAKE SYSTEMAnti±lock Brake System (A.B.S.)BR±103
HINT:
wºNew beltº refer to a belt which has been used 5 minutes
or less on a running engine.
wºUsed beltº refers to a belt which has been used on a running
engine for 5 minutes or more.
wAfter installing a belt, check that it fits properly in the
ribbed grooves.
wCheck by hand to confirm that the belt has not slipped out
of the groove on the bottom of the pulley.
wAfter installing a new belt, run the engine for about 5
minutes and recheck the belt tension.
4. VISUALLY CHECK ALTERNATOR WIRING AND
LISTEN FOR ABNORMAL NOISES
(a) Check that the wiring is in good condition.
(b) Check that there is no abnormal noise from the
alternator white the engine is running.
6. INSPECT CHARGING CIRCUIT WITHOUT LOAD
HINT: If a battery/alternator tester is available, connect the
tester to the charging circuit as per manufacturer's instruc-
tions.
(a) If a tester is not available, connect a voltmeter and ammeter
to the charging circuit as follows:
wDisconnect the wire from terminal B of the alternator and
connect it to the negative H probe of the ammeter.
wConnect the positive (+) probe of the ammeter to terminals
B of the alternator.
wConnect the positive (+) probe of the voltmeter to terminal
B of the alternator.
wGround the negative (±) probe of the voltmeter. 5. INSPECT CHARGE WARNING LIGHT CIRCUIT
(a) Warm up the engine and then turn it off.
(b) Turn off all accessories.
(c) Turn the ignition switch to ºONº. Check that the charge
warning light is lit.
(d) Start the engine. Check that the light goes out.
If the light does not go off as specified, troubleshoot the
charge light circuit.
± CHARGING SYSTEMOn±Vehicle InspectionCH±4
5. INSPECT NO±2 COOLING FAN RELAY
(ºAC FAN NO.2º)
A. Inspect relay continuity
(a) Using an ohmmeter, check that there is continuity between
terminals 2 and 6.
(b) Check that there is continuity between terminals 1 and 3.
(c) Check that there is no continuity between terminals 1
and 4.
If continuity is not as specified, replace the relay. 2. INSPECT WATER TEMPERATURE SENSOR
Using an ohmmeter, measure the resistance between the
terminals.
Resistance:
Approx. 1.53 k at 80°C (176° F)
Approx. 1.18 k at 90°C (194° F)
Approx. 1.03 k at 95°C (203°F)
If resistance is not as specified, replace the sensor.
3. INSPECT ENGINE MAIN RELAY (See page CH±16)
4. INSPECT NO.1 COOLING FAN RELAY (ºFAN NO.1 º)
(See page CO±22)
Ignition switch ON Ignition switch ON Tester connectionSpecified valve Condition
Battery voltageBattery voltage
Coolant temp.
Continuity
ContinuityContinuity ResistanceContinuity Check for
Voltage
Voltage
± COOLING SYSTEMElectric Cooling Fans (2VZ±FE)CO±25
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
TROUBLESHOOTING
TROUBLESHOOTING HINTS
1. Engine troubles is usually not caused by the EFI system.
When troubleshooting, always first check the condition of
the other systems.
(a) Electronic source
wBattery
wFusible links
wFuses
(b) Body ground
(e) Fuel supply
wFuel leakage
wFuel filter
wFuel pump
(d) Ignition system
wSpark plugs
wHigh±tension cords
wDistributor
wIgnition coil
wIgniter
(e) Air induction system
wVacuum leaks
(f) Emission control system
wPCV system
wEGR system
(g) Others
wIgnition timing (ESA system)
wdle speed (ISC system)
wetc.
2. The most frequent cause of problems is simply a bad contact
in wiring connectors. Always check that connections are
secure.
When inspecting the connector, pay particular attention to
the following points:
(a) Check to see that the terminals are not bent.
(b) Check to see that the connector is pushed in completely and
locked.
(e) Check to see that there is no signal change when the con-
nector is slightly tapped or wiggled.
3. Troubleshoot sufficiently for other causes before replacing
the ECU, as the ECU is of high quality and it is expensive.
± EFI SYSTEMTroubleshootingFI±10
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