This behavior can show up in the bay during service if certain precautions are not taken. The engine could start in the middle of an oil change, or the electrically driven A/C compressor could turn on during a recharge.
Don’t take chances. Always check the service information for the disable procedures. Some vehicles may require that the key be a certain distance from the vehicle. Others may require a scan tool to disable certain functions. Never assume that one model year of a hybrid is the same as the next. Many manufacturers made sweeping changes due to improvements in software and hardware.
Starting an engine is the greatest cause of wear on any engine, and hybrids regularly shut down and restart the engine more than a conventional vehicle.
Always make sure the fluid is at the correct level. Most manufacturers recommend flushing and filling the system when the engine’s cooling system is serviced.
If a different type of oil somehow makes its way into one of these compressors, and if the insulation on the windings is damaged or compromised, a variety of problems may occur.
The greatest risk is that the oil may conduct high voltage to the compressor case or connected components. A person may receive an electric shock if they touch the compressor, engine, etc., and an appropriate ground.
On the second and third generation Civic Hybrids, a combination belt/electric drive and A/C compressor is used and requires a special insulating compressor oil: Sanden SE-10Y (P/N 38899-RCJ-A01).
The A/C compressor works in conjunction with the engine’s idle stop system to keep the A/C going if the engine shuts off when the vehicle is stopped. Normally, the engine stop system will kill the engine momentarily when the vehicle comes to a halt after being driven at 7 mph or faster.
Courtesy Underhood Service.