GENERAL INFORMATION


AUTO STOP & GO (AS&G) SYSTEM
The purpose of the Auto Stop & Go (AS&G) system is to reduce CO2 exhaust gases from vehicles. The AS&G system automatically should stop the engine when the vehicle is stopped. And also the system should automatically restart the engine when the vehicle is started. The AS&G-ECU judges whether the engine should be stopped or restarted. The AS&G-ECU also stops or restarts the engine. The AS&G-ECU monitors the vehicle condition by using the signals from sensors and each ECU. If the specified conditions are satisfied, the AS&G-ECU should send the engine stop request signal to the engine-ECU via CAN. When receiving the signal, the engine-ECU should stop the engine (auto stop). When the driver depresses the clutch pedal during the auto stop, the AS&G-ECU should turn on the starter relay and the starter cut relay to drive the starter, also should send the engine start request signal to the engine-ECU via CAN. When receiving the signal, the engine-ECU should restart the engine (auto start).
System Configuration Diagram

1. Auto Stop & Go (AS&G) System

When the ignition switch is turned ON or when the engine starts, the AS&G system should automatically be turned ON. The driver can turn OFF the AS&G system by pressing the AS&G OFF switch. At that time, the AS&G OFF indicator/display should be turned ON in the combination meter. When the AS&G OFF switch is pressed again, the AS&G system should be turned ON.

2. Auto Stop Control

When the following operations are carried out in the AS&G system ON status, the AS&G-ECU should send the engine stop request signal to the engine-ECU. When receiving the signal, the engine-ECU should stop the engine.

  1. While letting the vehicle run and perfectly stop, depress the clutch pedal to place the gearshift lever in the neutral position.
  2. Release the clutch pedal.
During the auto stop, the AS&G indicator/display is turned ON in the combination meter. When one or more of following conditions are satisfied, the AS&G-ECU should prohibit the auto stop.

  • After the key/engine switch is used to start the engine, approximately 30 seconds have not been taken.
  • The accelerator pedal is depressed.
  • If the vehicle is stopped again within approximately 10 seconds of the engine auto start.
  • More than the vehicle speed of approximately 5 km/h is not detected even once after the engine start, including the engine start of the auto start.
  • The auto stop prohibition signal is received from the engine-ECU (Refer to GROUP 13B - General Information <4N1>, Refer to GROUP 13D - General Information <4A9>).
  • The auto stop prohibition signal is received from the A/C-ECU (Refer to GROUP 55 - General Information ).
  • The vacuum pressure of the brake booster is less than specified value.
  • The engine-ECU detects an abnormality in the AS&G system.
  • The AS&G-ECU detects an abnormality in the AS&G system.
  • The driver’s seat belt is unfastened.
  • The hood is opened.
  • The ambient temperature is lower than approximately 0°C

3. Auto Start Control
caution If the following motions are carried out during the auto stop even one time, the AS&G-ECU should blink the AS&G indicator/display in the combination meter and prohibits the auto start. Even if trying to return to the previous status after that, the auto start should be prohibited. When restarted, the engine must be started by the key/engine switch.

  • In case the hood is opened
  • In case the driver’s seat belt is unfastened

Normal Auto Start


When the driver depresses the clutch pedal during the auto stop, the AS&G-ECU should turn on the starter relay and the starter cut relay to drive the starter, also should send the engine start request signal to the engine-ECU via CAN. When receiving the signal, the engine-ECU should restart the engine. When the engine starts, the AS&G indicator/display in the combination meter should go off. When the following conditions are satisfied during the auto stop, the AS&G-ECU should prohibit the auto start.

  • AS&G system: OFF*
  • Gearshift lever position: except neutral position
note *: Pressing the AS&G OFF switch again to turn ON the AS&G system can enable the auto start.

Forcible Auto Start
When one of the following conditions is satisfied during the auto stop, the AS&G-ECU should send the engine start request signal to the engine-ECU for starting the engine swiftly despite the driver’s determination. Also, the AS&G-ECU should turn on the starter relay and the starter cut relay to drive the starter. At that time, the AS&G indicator/display in the combination meter should go off as well as the normal auto start.

  • The vehicle speed is more than 3 km/h.
  • The vacuum pressure of the brake booster is less than specified value.
  • The engine start request signal is received from the A/C-ECU (Refer to GROUP 55 - General Information ).
  • The engine start request signal is received from the engine-ECU (Refer to GROUP 13B - General Information <4N1>, Refer to GROUP 13D - General Information <4A9>).
  • The AS&G-ECU detects an abnormality in the AS&G system.
When the following conditions are satisfied during the auto stop, the AS&G-ECU should prohibit the forcible auto start.

  • AS&G system: OFF*
  • Gearshift lever position: except neutral position
note *: Pressing the AS&G OFF switch again to turn ON the AS&G system can enable the forcible auto start.

4. Control for Increasing Voltage
At the auto start, the AS&G-ECU sends the increasing voltage request signal to the DC/DC converter. When receiving the signal, the DC/DC converter should temporarily switch the relay in the unit to the voltage converter of the DC/DC converter. The voltage converter increases the battery voltage dropping during cranking to 12.2 V. This can prevent the jumpy sound of the audio equipment due to the battery voltage drop at the auto start. The DC/DC converter should stop increasing the voltage when the input voltage returns to 12.2 V.

5. AS&G System Indicator/Display Control

The AS&G-ECU sends the signal to the combination meter via CAN, corresponding to the operation of the AS&G system. The combination meter that received the signal turns ON or blinks the indicator/display. Then the AS&G system status is informed to the driver.
AS&G system
 Condition
 AS&G OFF indicator/display
 AS&G indicator/display
OFF
 Ignition switch: ON (engine is stopped.); After several seconds are taken
 Illuminated/Displayed
 Extinguished/Not displayed
During engine running
 Illuminated/Displayed
 Extinguished/Not displayed
ON
 Ignition switch: ON (engine is stopped.); After several seconds are taken
 Extinguished/Not displayed
 Extinguished/Not displayed
During idling and driving
 Extinguished/Not displayed
 Extinguished/Not displayed
During auto stop
 Extinguished/Not displayed
 Illuminated/Displayed
Hood is opened
 Extinguished/Not displayed
 Blinked
Driver’s seat belt is unfastened
 Extinguished/Not displayed
 Blinked
During auto stop, shift lever is operated*1
 Extinguished/Not displayed
 Blinked
ON/OFF
 After ignition switch ON; for several seconds
 Illuminated/Displayed
 Illuminated/Displayed
AS&G system is abnormal*2
 Blinked
 Extinguished/Not displayed
note *1: When detecting that the gearshift lever is in other than neutral position during the auto stop, the AS&G-ECU should send the request signal to the combination meter via the CAN to sound the warning buzzer. When receiving the signal, the combination meter should sound the built-in warning buzzer. This warns the driver about the dangerous operation, prohibiting the auto start.
note *2: The AS&G-ECU or the engine-ECU may detect a diagnosis code. Check whether the each ECU detects a diagnosis code or not.

6. Starter Relay Control
At Normal Engine Start
    When the following signals are input, the AS&G-ECU should turn ON the both of the power transistor of the starter cut relay in the unit and the power transistor of the starter relay in the unit. This allows the starter cut relay and the starter relay to be turned ON, and then the starter is driven. If the immobilizer result checking has some discrepancy, the output to the starter relay should be turned OFF. The starter, therefore, should not be driven.

    • Ignition switch-ST signal
    • Clutch interlock switch ON signal (the clutch pedal is fully depressed)
At Engine Start from Auto Stop Status
    When detecting one of the following conditions during the auto stop, the AS&G-ECU should turn ON the both of the power transistor of the starter cut relay in the unit and the power transistor of the starter relay in the unit. This allows the starter cut relay and the starter relay to be turned ON, and then the starter is driven.

    • Neutral position switch: ON; Clutch monitoring switch: ON (the clutch pedal is depressed.)
    • Neutral position switch: ON and the conditions of the forcible auto start are satisfied