Tap-Up/Down Control Function; Auto Cancel Function; Automatic Transaxle Control Function - Toyota Camry 1999 Electrical Troubleshooting Manual

7. TAP–UP CONTROL FUNCTION
When the difference between the actual vehicle speed and the set speed is less than 5 km/h (3 mph), the set speed can be
increased 1.6 km/h (1 mph) each time by operation the RESUME/ACCEL SW quickly within 0.6 seconds.
8. TAP–DOWN CONTROL FUNCTION
When the difference between the actual vehicle speed and the set speed is less than 5 km/h (3 mph), the set speed can be
lowered 1.6 km/h (1 mph) each time by operating the SET/COAST SW quickly within 0.6 seconds.

9. AUTO CANCEL FUNCTION

A) If any of the following operating conditions occurs during cruise control operation, the set speed is erased, the current
flow to the magnetic clutch is stopped and the cruise control is released. (Cruise SW turns off).
When this occurs, the ignition SW must be turned off once before the cruise SW will turn on.
∗ When current continued to flow to the motor inside the actuator in the throttle valve "OPEN" direction.
∗ The motor does not operate despite the motor drive signal being output.
B) If any of the following operating conditions occurs during cruise control operation, the set speed is erased, the current
flow to the magnetic clutch is stopped and the cruise control is released. (Cruise SW turn off).
When this occurs, the cancel state is cleared as the cruise SW will turn on again.
∗ Over current to transistor driving the motor and/or the magnetic clutch.
∗ Open circuit in the magnetic clutch.
∗ Momentary interruption of vehicle speed signal.
∗ Short circuit in the cruise control SW.
∗ When the vehicle speed falls more than 16 km/h (10 mph) below the set speed, E.G. on an upward slope.
C) If any of the following conditions occurs during cruise control operation, the set speed is erased and the cruise control is
released. (The power to the magnetic clutch is cut off until the set SW is ON again.)
∗ When the vehicle speed falls below the minimum speed limit, approx. 40 km/h (25 mph).
∗ When power to the cruise control system is momentarily cut off.
D) If any of the following conditions occurs during cruise control operation, the cruise control is released.
∗ Open the circuit for TERMINAL 2 of the stop light SW.

10. AUTOMATIC TRANSAXLE CONTROL FUNCTION

∗ In overdrive. If the vehicle speed becomes lower than the overdrive cut speed (Set speed minus approx. 4 km/h, 2.5 mph)
during cruise control operation, such as driving up a hill, the overdrive is released and the power increased to prevent a
reduction in vehicle speed.
∗ After releasing the overdrive, vehicle speed becomes higher than the overdrive return speed (Set speed minus approx. 2
km/h, 1.2 mph) and the cruise control ECU judges by the signals from the actuator's potentiometer that the upward slope
has finished, the overdrive is resumed after approximately 2 seconds.
∗ During cruise control driving, the cruise control operation signal is output from the cruise control ECU to the engine control
module. Upon receiving this signal, the engine control module changes the shift pattern to normal.
To maintain smooth cruise control operation (on a downward slope etc.), the lock–up release of the transmission when the
idling point of the throttle position is ON is forbidden.
SERVICE HINTS
C3 CRUISE CONTROL ACTUATOR
3–4 : Approx. 38.5 Ω
C12 CRUISE CONTROL SW [COMB. SW]
5–3 : Continuity with the CRUISE SW on
4–3 : Approx. 418 Ω with the CANCEL SW on
Approx. 68 Ω with the RESUME/ACCEL SW on
Approx. 198 Ω with the SET/COAST SW on
C15 CRUISE CONTROL ECU
9–GROUND : 10–14 volts with the ignition SW at ON position
12–GROUND : 4 pulses with 1 rotation of rotor shaft
10–GROUND : Approx. 418 Ω with the CANCEL SW on in the cruise control SW
Approx. 198 Ω with the SET/COAST SW on in the cruise control SW
Approx. 68 Ω with the RESUME/ACCEL SW on in the cruise control SW
16–GROUND : Always continuity