Diagnostic Aids
WARNING: This page is about a different car, the 2017 GMC Acadia. However, it is still accessible from the selected car via links, so may be relevant.
- If the driver does not fully depress the brake pedal, the vehicle may not enter Auto Stop mode.
- Auto Stop may be deactivated if any of the following conditions are present:
- Economy mode turned OFF by driver
- Ambient and coolant temperature correlation does not match specified values
- Ambient temperature is less than -10°C (14°F)
- Battery temperature is less than 0°C (32°F) or greater than 55°C (131°F)
- Clutch (manual transmission) or accelerator pedal is pressed
- HVAC system demand is high
- HVAC defrost has been selected
- Battery charge is low
- The learn procedure needs to be completed on the Battery Sensor Module
- If the Battery Sensor Module is not calibrated, the Autostop/Autostart system will be disabled. Some causes of the Battery Sensor Module being out of calibration include:
- The battery was replaced
- The battery negative cable was disconnected and reconnected
- The battery was improperly charged:
To properly charge the battery, the negative lead of the charger must be connected to chassis ground, NOT directly to the negative battery post. Connecting to chassis ground allows current to flow through the battery sensor module during charging and be measured. Connecting directly to the negative battery post charges the battery, but the current is not measured by the battery sensor module.
- The Battery Sensor Module was not calibrated correctly
- The Battery Sensor Module was disconnected and reconnected
- Vehicle has not been allowed to sit for at least 3 hours over 1 week.
- When using a vehicle hoist to verify autostop and autostart operation, ensure the following conditions are also met:
- Transmission gear selector is in the drive position
- No DTCs are set
- Traction control is off