2013 Buick Regal Owner Manual - Page 218

9-22 Driving and Operating ... There are several conditions which may prevent an auto stop or cause an auto start. The Engine Will Remain Running When: . The hood is not fully closed. Brake pedal pressure is low. If the MIL is on, auto stop may be prevented. High humidity is detected. The brake pedal is released. The accelerator pedal is applied. Shifting out of D (Drive) to any other gear. The air conditioning or defrost system need the compressor to maintain vehicle comfort. See Dual Automatic Climate Control System on page 8‑1. The warmer it is outside, the shorter the time before the engine is restarted to provide cabin cooling. To maximize fuel economy, use the eco air conditioning mode. . The climate control system is turned from off to normal air conditioning or defrost. See Dual Automatic Climate Control System on page 8‑1. The engine is required to run for either heater or climate control performance. See Dual Automatic Climate Control System on page 8‑1. The high voltage battery pack charge is low and requires recharging. Auto stop time is greater than two minutes. The hood is opened. . . The engine, transmission, or high voltage battery is not warmed up yet. The outside temperature is less than −20°C (−4°F). The air conditioning or defrost system need the compressor to maintain vehicle comfort. See Dual Automatic Climate Control System on page 8‑1 The warmer it is outside, the shorter the time before the engine is restarted to provide cabin cooling. To maximize fuel economy, use the eco air conditioning mode. The shift lever is in P (Park), N (Neutral), R (Reverse), or M (Manual Mode). The high voltage battery pack charge is low. The Engine Will Restart When: ... . . . . . . Engine Heater The engine coolant heater, if available, can help in cold weather conditions at or below −18°C (0°F) for easier starting and better fuel economy during engine warm-up. Plug in the coolant heater at least four hours before starting the vehicle. An internal thermostat in . .