Autostop Criteria
WARNING: This page is about a different car, the 2017 Cadillac ATS. However, it is still accessible from the selected car via links, so may be relevant.
The ECM will send an Autostop state message to the body control module (BCM) and shut down the engine when all of the following criteria is met. The BCM will transmit the Autostop state message to the instrument cluster which will display the Autostop indicator in the tachometer display.
- Initial minimum vehicle speed during drive cycle must be 19 km/h (12 MPH) or greater. Subsequent autostop minimum speed may vary from 2-10 km/h (1-6 MPH), depending on vehicle
- Ambient and engine coolant temperature correlation meets specified values.
- Ambient and transmission fluid temperature correlation meets specified values.
- Hood switch status is closed
- Driver door status is closed
- Driver seat belt status is buckled
- Brake booster vacuum is greater than 45 kPa (7 PSI)
- Transmission gear selector is in the Drive position
- Vehicle speed is less than 5 km/h (3 MPH)
- Engine speed is below 1500 RPM
- Engine coolant temperature is less than 120°C (248°F)
- Ambient temperature is greater than -10°C (14°F)
- No A/C compressor request from HVAC (A/C or Defrost modes)
- Battery voltage greater than 12 V
- Battery state of charge greater than 75% (changes with state of health)
Autostop Enable Ambient and Engine Coolant Temperature Table
| Ambient Temperature | Minimum Coolant Temperature | Autostop Enable |
|---|---|---|
| -10°C (14°F) | 60°C (140°F) | Yes |
| 0°C (32°F) | 50°C (122°F) | Yes |
| 6°C (43°F) | 40°C (104°F) | Yes |
| 12°C (54°F) | 30°C (86°F) | Yes |
| 20°C (68°F) | 18°C (64°F) | Yes |
| 30°C (86°F) | 18°C (64°F) | Yes |