Toyota Scion tC 2005 Wiring Diagram page 192

System Outline
The cruise control system is a constant vehicle speed controller in which control of the switch on the instrument panel makes
it possible to automatically adjust the opening of the engine throttle valve without depressing of the accel pedal.
1. Set Operation
When the ON–OFF SW is turned on, the system starts preparations necessary for the cruise control and turns on the
indicator light in the combination meter.
2. Set Speed Control
When the – SET SW is operated with the ON–OFF SW turned on during travelling, the constant vehicle speed is controlled.
3. Coast Control
When the – SET SW is kept turned on during cruise control travelling, the engine control module controls the throttle valve to
decelerate the vehicle. Every time the – SET SW is turned on instantaneously, the vehicle speed is decelerated
approximately 1.6 km/h. However, in case of tap–down operation to make more than 5 km/h gap between the set speed and
the actual vehicle speed, the device recalls the original set speed and controls it at the speed constantly.
4. Accel Control
When the + RES SW is kept turned on during cruise control travelling, the engine control module controls the throttle valve to
accelerate the vehicle. Every time the + RES SW is turned on instantaneously, the vehicle speed is accelerated
approximately 1.6 km/h. However, in case of tap–up operation to make more than 5 km/h gap between the set speed and
the actual vehicle speed, the device do not change the set speed. (Tap–up operation is not available.)
5. Resume Control
When the vehicle speed is within the low speed limit (Approximately 40 km/h, 25 mph) if the cruise control is cancelled, use
of the + RES SW accelerates the vehicle to the speed level used before canceling the cruise control.
6. Manual Cancel Mechanism
If any of the following signals is input during cruise control travelling, the cruise control is cancelled.
∗ The stop lamp SW is turned on. (The brake pedal depressed)
∗ The CANCEL SW is turned on.
∗ The ON–OFF SW is turned off.
∗ The cruise control clutch SW is turned off. (M/T) (The clutch pedal depressed)
7. Auto Cancel Function
If any of the following conditions is encountered, the cruise control is automatically cancelled.
∗ Disconnection and/or short in the stop light SW
∗ Malfunction in the vehicle speed signal
∗ Malfunction in the electronic throttle parts
∗ Malfunction in the stop lamp SW input circuit
∗ Malfunction in the cancel circuit
∗ The actual vehicle speed becomes slower than the minimum speed limit
∗ The actual vehicle speed becomes –16 km/h slower than the set speed
8. Overdrive Control Function
Overdrive is sometimes cut off on gradients during cruise control driving. When end of climbing gradient is determined by
throttle opening degree information after overdrive is canceled, control is reset to overdrive condition after overdrive resetting
timer operation. Also, when overdrive is cut off during accelerator resuming control, control is reset to overdrive condition
when accelerator resuming control is finished.
Service Hints
E4 (A), E5 (B), E6 (C), E7 (D), E8 (E) Engine Control Module
(A) 9–Ground : Approx. 12 volts with the ignition SW at ON position
(B) 6, (A) 3–Ground : Always approx. 12 volts
(A)15, (C) 1, (C) 4, (C) 7, (D) 7, (E) 6, (E) 7–Ground : Always continuity
(B)19–Ground : Approx. 12 volts with the brake pedal depressed
(B)24–Ground : Continuity with the cruise control ON–OFF SW at on
Approx. 1540 Ω with the CANCEL SW on in cruise control SW
Approx. 240 Ω with the + RES SW on in cruise control SW
Approx. 630 Ω with the – SET SW on in cruise control SW
S7 Spiral Cable
5–4 : Approx. 1540 Ω with the CANCEL SW on
Approx. 240 Ω with the + RES SW on
Approx. 630 Ω with the – SET SW on
2005 SCION tC (EWD572U)
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