TOYOTA CAMRY 1999 Service Repair Manual

DI08M±13
Duty Ratio =A + BA
x 100 (%)
ON
OFFA
B
1 cycle
N21216
Cruise Control ECU
MO
7
MC
R±B Cruise Control Actuator
R±G 1
215

Actuator Motor
C3
C3C16
C16
± DIAGNOSTICSCRUISE CONTROL SYSTEM
DI±329
CIRCUIT INSPECTION
DTC 11, 15 Actuator Motor Circuit
CIRCUIT DESCRIPTION
The actuator motor is operated by signals from the ECU. Acceleration and deceleration signals are trans-
mitted according to changes in the Duty Ratio (See below).
Duty Ratio
The duty ratio is the ratio of the period of continuity in one cycle. For example, if A is the period of continuity
in one cycle, and B is the period of non±continuity.
DTC No.DTC Detecting ConditionTrouble Area
11Short in actuator motor circuit.
Actuator motor
Harness or connector between cruise control ECU and
actuator motor
Cruise control ECU
15Open in actuator motor circuit.Actuator motor
WIRING DIAGRAM

I00004
I00151
ON
2
1
DI±330
± DIAGNOSTICSCRUISE CONTROL SYSTEM
INSPECTION PROCEDURE
1 Check resistance between terminals MO and MC of actuator motor.
PREPARATION:
(a) Turn ignition switch ON.
(b) Disconnect the actuator connector.
CHECK:
Measure resistance between terminals 1 and 2.
HINT:
If control plate is in fully opened or fully closed positions, resis-
tance can not be measured.
OK:
Resistance: more than 4.2 W
NG Replace cruise control actuator.
OK
2 Check for open and short in harness and connectors between cruise control
ECU and actuator motor (See page IN±29).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU
(See page IN±29).

I00281
Cruise Control ECU
C16
G±B
2 1 34W±B
3
STOP Fuse8 Stop Light Switch
4
R±Y
Stop Lights Cruise Control Actuator

Actuator Magnetic Clutch
J6
J6AAJ/C
W±B
1J
1J
W±B
A
J/C
IF 8
7
J9Instrument
Panel J/BL
± DIAGNOSTICSCRUISE CONTROL SYSTEM
DI±331
DTC 12 Actuator Magnetic Clutch Circuit
CIRCUIT DESCRIPTION
This circuit turns on the magnetic clutch inside the actuator during cruise control operation according to the
signal from the ECU. If a malfunction occurs in the actuator or speed sensor, etc. during cruise control opera-
tion, the rotor shaft between the motor and control plate is released.
When the brake pedal is depressed, the stop light switch turns on, supplying electrical power to the stop light.
Power supply to the magnetic clutch is mechanically cut and the magnetic clutch is turned OFF.
When driving downhill, if the vehicle speed exceeds the set speed by 15 km/h (9 mph), the ECU turns the
safety magnet clutch OFF. If the vehicle speed later drops to within 10 km/h (6 mph), cruise control at the
set speed is resumed.
DTC No.DTC Detecting ConditionTrouble Area
12Short in actuator magnetic clutch circuit.
Open (0.8 sec.) in actuator magnetic clutch circuit.
STOP Fuse
Stop light switch
Actuator magnetic clutch
Harness or connector between cruise control ECU and
actuator magnetic clutch, actuator magnetic clutch and body
ground
Cruise control ECU
WIRING DIAGRAM
DI08N±13

I00157
Instrument panel junction block No.1:
STOP Fuse
I00133
21
43
DI±332
± DIAGNOSTICSCRUISE CONTROL SYSTEM
INSPECTION PROCEDURE
1 Check STOP fuse.
PREPARATION:
(a) Turn ignition switch OFF.
(b) Remove the STOP fuse from instrument panel junction
block No.1.
CHECK:
Check fuse continuity.
OK:
There is continuity.
NG Replace STOP fuse.
OK
2 Check stop light switch.
PREPARATION:
Disconnect the stop light switch connector.
CHECK:
Check continuity between terminals.
Switch positionContinuity
Switch pin free
(Brake pedal depressed)1 ± 2
Switch pin pushed in
(Brake pedal released)3 ± 4
NG Replace stop light switch.
OK

I00311
4
3
± DIAGNOSTICSCRUISE CONTROL SYSTEM
DI±333
3 Check resistance between terminals L and GND of actuator magnetic clutch.
PREPARATION:
(a) Turn ignition switch OFF.
(b) Disconnect the actuator connector.
CHECK:
Measure resistance between terminals 3 and 4.
OK:
Resistance: 34.65 ± 42.35 W
NG Replace cruise control actuator.
OK
4 Check for open and short in harness and connectors between cruise control
ECU and actuator magnetic clutch, actuator magnetic clutch and body ground
(See page IN±29).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU
(See page IN±29).

I00055
4
3(+)
(±)
DI±334
± DIAGNOSTICSCRUISE CONTROL SYSTEM
DTC 14 Actuator Mechanical Malfunction
CIRCUIT DESCRIPTION
The circuit detects the rotation position of the actuator control plate and sends a signal to the ECU.
DTC No.DTC Detecting ConditionTrouble Area
14Cruise control actuator mechanical malfunction.

Actuator lock: (motor, arm)

Actuator motor

Cruise control ECU
WIRING DIAGRAM
See page DI±329.
INSPECTION PROCEDURE
1 Check cruise control actuator arm locking operation
PREPARATION:
(a) Turn ignition switch OFF.
(b) Disconnect the actuator connector.
CHECK:
Connect the positive (+) lead from the battery to the terminal 3
of actuator and the negative (±) lead to terminal 4.
NOTICE:
Do not connect the high tension cables to the wrong bat-
tery terminal. The cruise control actuator will be damaged.
Move the control plate by hand.
OK:
Control plate doesn't move.
NG Replace cruise control actuator.
OK
DI08O±13

I08437
Fully open side
Fully Closed sideControl plate
Control plate4
321
4
321
± DIAGNOSTICSCRUISE CONTROL SYSTEM
DI±335
2 Check cruise control actuator operation.
PREPARATION:
(a) Turn ignition switch OFF.
(b) Disconnect the actuator connector.
CHECK:
Connect the positive (+) lead from the battery to terminals 1 and
3 of actuator, connect the negative (±) lead to terminals 2 and
4 of actuator.
OK:
Control arm moves to fully open side
CHECK:
Connect the positive (+) lead from the battery to terminals 2 and
3 of actuator, connect the negative (±) lead to terminals 1 and
4 of actuator.
OK:
Control arm moves to fully colsed side
NG Replace cruise control actuator.
OK
3 Check harness and connector between cruise control ECU and cruise control ac-
tuator (See page IN±29).
NG Repair or replace harness or connector.
OK
Check and replace cruise control ECU
(See page IN±29).

I00292
Vehicle Speed Sensor
ECUCombination Meter
Cruise Control ECU
4 pulses/
1 rotation
of rotor shaft4 pulses/
1 rotation
of rotor shaft
I00282
Cruise Control ECU
12
SPDV±W V±WB
BJ15
J/CIF1
3
V±W14
Combination Meter
15
6
Speedo
±meter
P L
IH12IH17
P
3L
2
SI
SE
IG+
1
R±Lto GAUGE Fuse
C16
C11 C11
C12
Speed
Sensor DI±336
± DIAGNOSTICSCRUISE CONTROL SYSTEM
DTC 21 Open in Vehicle Speed Sensor Circuit
CIRCUIT DESCRIPTION
The signal from the vehicle speed sensor circuit is sent to cruise control ECU as vehicle speed signal.
The rotor shaft is driven by the gear of the transmission.
For each rotation of the shaft, the vehicle speed sensor sends a 4±pulse signal through the combination
meter to the cruise control ECU (See the following installation).
This signal is converted inside the combination meter and sent as a 4±pulse signal to the cruise control ECU.
The ECU calculates the vehicle speed from this pulse frequency.
DTC No.DTC Detecting ConditionTrouble Area
21Speed signal is not input to the cruise control ECU while cruise
control is set.

Combination meter

Harness or connector between cruise control ECU and com-
bination meter, combination meter and vehicle speed sensor

Vehicle speed sensor

Cruise control ECU
WIRING DIAGRAM
DI08P±13

Input SignalIndicator Light
Blinking Pattern
Drive at about
40 km/h (25 mph)
or below
Drive at about
40 km/h (25 mph)
or higherLightON
OFF
LightON
OFF
± DIAGNOSTICSCRUISE CONTROL SYSTEM
DI±337
INSPECTION PROCEDURE
1 Input signal check.
CHECK:
(a) See input signal check on page DI±319.
(b) Check indicator light operation when driving with vehicle
speed above 40 km/h (25 mph), and with vehicle speed
below 40 km/h (25 mph).
OK:
Vehicle speed above 40 km/h (25 mph):
Indicator light blinks
Vehicle speed below 40 km/h (25 mph):
Indicator light stays on
OK Check and replace cruise control ECU
(See page IN±29).
NG
2 Check speedometer circuit (See Combination meter troubleshooting on page
BE±1).
NG Repair or replace harness, connector or com-
bination meter assembly.
OK
3 Check harness and connector between cruise control ECU and combination me-
ter, combination meter and vehicle speed sensor (See page IN±29).
NG Repair or replace harness or connector.
OK

DI±338
± DIAGNOSTICSCRUISE CONTROL SYSTEM
4 Check vehicle speed sensor (See Pub. No. RM654U on page BE±47).
NG Replace vehicle speed sensor.
OK
Check and replace cruise control ECU
(See page IN±29).