1986 TOYOTA CAMRY V20 ESP

Cruise Control Computer Circuit
INSPECTION OF COMPUTER CIRCUIT
Disconnect the computer and inspect the connector on
wire harness side as shown in the below.
Remove CHARGE fuse and
ignition switch turned on with
parking brake lever released. Clutch pedal released or shifted
into only range except
ºNº and ºPº range
Remove CHARGE fuse and
ignition switch turned on with
parking brake lever pulled up.
Apply vacuum approx. 170
mmHg (fi.69 in.Hg, 22.7 kPa)Turn ignition switch and main
switch on
Turn ignition switch and main
switch off
Turn ignition switch and main
switch off Turn ignition switch and main
switch on
Clutch pedal depressed or
shifted into ºNº range Clutch Switch
(M/T) or Neutral
Start Switch (A/T)1 pulse each 44 cm
(15.75 in.) Stop Light Switch
and Release Valve
Turn resume/accel switch offTurn resume/accel switch on Control Switch
(indicator circuit)
Connection or
measure rtem
Turn set/coast switch off Turn set/coast switch on
Control Switch
(resunne/accel)Control Switch
(set/coast)
Vehicle moving slowlyBrake pedal depressed
Parking Brake
SwitchBrake pedal releasedBrake pedal released
10 ± Body ground
13 ± Body ground16 ± Body ground
17 ± Body ground
12 ± Body ground11 ± Body ground15 ± Body ground Tester connection
Stop Light Switch
3 ± Body ground
5 ± Body ground
7 ± Body ground
1 ± Body ground 9 ± Body groundBattery voltageSpecified value
Battery voltage
Battery voltageBattery voltage
Battery voltage No continuity
Vacuum SwitchControl Switch
Vacuum PumpNo continuity Approx. 68

Speed Sensor
No continuity Approx. 30

No continuity
Body GroundControl Valve
No voltageNo voltage
Continuity
Continuity ContinuityContinuity Resistance
ContinuityContinuity
Continuity Continuity
ContinuityNo voltage
No vacuum
ContinuityContinuityContinuity
ContinuityNo vohage
Condition
Resistance Stop FuseCheck for
VoltageVoltage Voltage
Voltage
Voltage4±142±14
± BODY ELECTRICAL SYSTEMCruise Control SystemBE±88

INITIAL CHECK
CHECK ACTUATOR OPERATION NOISE
(a) Start the engine and drive at a speed over 6 km/h
(4 mph).
(b) Check that the actuator operation noise is heard.
HINT: A initial check is carried out once each time after the
engine has been started and initial speed exceeds 6
km/h (4 mph). The respective functions, in order, of the 3
position solenoid and pump motor in the actuator are
checked. However, if the brake pedal is depressed, the ini-
tial check is not carried out, but is started after the pedal
has been released.
INSPECTION OF DIAGNOSIS SYSTEM
1. INSPECT BATTERY VOLTAGE
Inspect that the battery voltage is about 12 V.
2. CHECK THAT WARNING LIGHT TURNS ON
(a) Turn the ignition switch on.
(b) Check that the ºANTILOCKº warning light turns on for
3 seconds.
If not, inspect and repair or replace the fuse, bulb and wire
harness.
Diagnosis System
DESCRIPTION
If a malfunction occurs, the system will identify the prob-
lem and the computer will store the codes for the trouble
items.
At the same time, the system informs the driver of a mal-
function via the ºANTILOCKº warning light in the combina-
tion meter.
By turning on the ignition switch and disconnecting the
check connector, the trouble can be identified by the
number of blinks (diagnostic code) of the warning light.
In the event of two codes, that having the smallest num-
ber (code) will be identified first.
HINT: The warning light does not show the diagnostic
codes while the vehicle is running.
± BRAKE SYSTEMAnti±lock Brake System (A.B.S.)BR±67

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

IF VEHICLE IS EQUIPPED WITH MOBILE
RADIO SYSTEM (HAM, CB, ETC.)
The ECU has been designed so that it will not be affected ±by out-
side interference.
However, if your vehicle is equipped with a CB radio transceiver,
etc. (even one with about 10 W output), it may, at times, have an
affect upon ECU operation, especially if the antenna and feeder are
installed nearby.
Therefore, observe the following precautions:
1. Install the antenna as far as possible from the ECU. The
ECU is located under the radio so the antenna should be installed
at the rear side of the vehicle.
2. Keep the antenna feeder as far away as possible from the
ECU wires ± at least 20 cm (7.87 in.) ± and, especially, do not wind
them together.
3. Check that the feeder and antenna are properly adjusted.
4. Do not equip your± vehicle with a powerful mobile radio system.
5. Do not open the cover or the case of the ECU unless absolutely nec-
essary. (If the IC terminals are touched, the IC
may be destroyed by static electricity.)
AIR INDUCTION SYSTEM
1. Separation of the engine oil dipstick, oil filler cap, PCV hose,
etc. may cause the engine to run out¿¿ tune.
2. Disconnection, looseness or cracks in the parts of the air
induction system between the throttle body and cylinder
head will allow air suction and cause the engine to run out of tune.
ELECTRONIC CONTROL SYSTEM
1. Before removing EFI wiring connectors, terminals, etc., first discon-
nect the power by either turning the ignition switch
OFF or disconnecting the battery terminals.
2. When installing the battery, be especially careful not to
incorrectly connect the positive (+) and negative (±) cables.
3. Do not permit parts to receive a severe impact during removal or
installation. Handle all EFI parts carefully, especially the ECU.
4. Do not be careless during troubleshooting as there are numerous
transistor circuits and even slight terminal contact can cause fur-
ther troubles.
5. Do not open the ECU cover.
6. When inspecting during rainy weather, take care to prevent
entry of water. Also, when washing the engine compartment, pre-
vent water from getting on the ER parts and wiring connectors.
7. Parts should be replaced as an assembly.
± EFI SYSTEMInspection PrecautionsFI±6

Diode Ohmmeter
Diode Ohmmeter
Digital Type Analog Type
Bulb Ohmmeter
A±6
INTRODUCTION±HOW TO PERFORM FOR SYSTEM INSPECTION
7
Wire Harness Repair Manual (RM1022E)
If the circuit has diodes, reverse the two leads and check
again.
When touching the negative (±) lead to the diode positive
(+) side and the positive (+) lead to the negative (±) side,
there should be continuity. When touching the two leads in
reverse, there should be no continuity.
HINT: Specifications may vary depending on the type of
tester, so refer to the tester's instruction manual before
performing the inspection.
Check LED (Light Emitting Diode) in the same manner as
that for diodes.
HINT:

Use a tester with a power source of 3V or greater to
overcome the circuit resistance.

If a suitable tester is not available, apply battery
voltage and check that the LED lights up.
(c)Use a volt/ohmmeter with high impedance (10kW/V
minimum) for troubleshooting of the electrical circuit.
3. Bulb Check
(a)Remove the bulb.
(b)There should be continuity between the respective
terminals of the bulb together with a certain amount
of resistance.
(c)Apply the two leads of the ohmmeter to each of the
terminals.
(d)Apply battery voltage and check that the bulb light up.
A

TERMINAL AND CONNECTOR REPAIR±TERMINAL REPLACEMENT
B±4
14
Wire Harness Repair Manual (RM1022E)
Step 1. Identify the connector and the terminal type.
Confirm whether the connector you require is the non±waterproof, waterproof or combined terminal type
connector from the pictures provided in the following charts.
Connector
Description
Non±Waterproof TypeThose connectors which are not of the
waterproof or combined terminal type.
Waterproof TypeWaterproof material (hole plug or terminal
packing) is provided on the terminal/connector
body.
Combined Terminal TypeTerminals of different shape/size are located in
one connector.
1. Terminal with Wire
Identify the part number of the terminal with wire by picking
out the corresponding illustration from the pictures
provided on the following charts.
HINT: In some of the illustrations, there are two part
numbers for the same illustration of terminal with wire,
because although the shapes of the terminals are
completely the same, there is a difference in with /without
gold±plating (gilded).
Remark: T h e length of the wire connected to the
terminal is approximately 150 mm.
B