2004 Chevy Malibu alarm randomly going off. Why?

https://www.chevymalibuforum.com/forums/60-problems-service-issues-troubleshooting-generations-5-6/3650-04-malibu-maxx-sudden-hard-shift.html

Debbie, code p0300 is a random misfire code,
- bad spark plug (s)
- bad ignition coil (s)
- plugged or faulty fuel injector (s)
- Intake leak
- injectors harness is open or shorted
- Injectors circuit has poor electrical connection
- Ignition coils harness is open or shorted
- Ignition coils circuit poor electrical connection
- Insufficient cylinders compression
- weak fuel pressure
see links below,

2006 Malibu P0300 random misfire

2004 Chevy Malibu with Code P0300

https://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=9&cad=rja&uact=8&ved=0ahUKEwj3i8uU-YbLAhVImx4KHaOhDcoQFghMMAg&url=http%3A%2F%2Fricksfreeautorepairadvice.com%2Ftag%2Fp0300%2F&usg=AFQjCNEEy9v40AO2Se1VIp-iekkFnE_E2g

Reset the alarm system lock and unlock all the doors twice.

natural for engine temp to rise in Traffic - Until Themostat opens ) cooling fan sensor kicks on fan . But Antifreeze is not just a Cold weather item . Coolant is Absolutely Necessary for Hot Days . You must be full to recovery bottle setting of cold when checked prior to start up . Coolant for your make / model is Reddish - Pink colour and should have a reading of -25 thats negative 25 degrees the Lower the Better even - 50 .. Why ?? - 50 is 50 %% antifreeze / Coolant Concentrate MIX Gives Hot weather cooling Ability or very cold weather starting / winter HEAT .

It may be the alarm is going out, if it has one a sensor may be defective

the main reason the alarm goes off by itself is usually due to the doors on the car. the alarm is triggered when the cotnrol system detects that a door has been opened. There should be 2-3 terminals that line up to make sure the door is closed. In the winter they can get frosted with ice or dirty from salt and road dirt. the contacts get greasy/grimy/dirty over time.

if the switches don't make a good electrical contact the slightest vibration can cause them to break contact and trick the security control unit into thinking that someone has attempted to open the door.
The easiest solution is to clean the contacts on the door switches on both sliding doors with isoprophol alcohol.

the doors use a plunger type switch that the door closes against. if either of those switches is loose it couldalso cause the same problem.

clean the contacts on the sliding door and see if the problem goes away. it probably will.

I also like to spray the rubber plunger receivers with a quick coat of silicone grease, this keeps the rubber from getting brittle and makes it less prone ot freezing in the winter.

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2004 chevy malibu crank no start/ scan computer found code b2930, basicly computor forgot the chip inbedded in key,turned on ign for ten minutes cycled key and car started has been fine for two(2) days

check the hood switch and all door switches that is normal problem

Make sure to check all doors, the trunk latch, and the hood to ensure that they are shut. I have looked up your 2006 Chevy Malibu and there has been a lot of people complaining about the alarm system and it going off. There is a TBS (Technical Service Bulletin) out for your car. The TBS says that the Faulty Door Sensor. Take it to your local dealership and tell him what I found for you and they should get you a quote on how much it would cost to repair it.

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you need to turn the sensitivity down check your owners manual or call your toyota dealer for instructions many toyotas have this problem in cold temp's.hope this is helpful