Hi Everyone, I have a problem with my 2004 toyota matrix. When the weather is very cold. like -20 degree C. its check engine light on. And it will stay there, until weather is getting warmer. please help me dialog the problem. Thanks.

We have had those OBD Check Lights for 35 years,
on all vehicles---so why the question ?

Everyone gets one once a year & has vehicle issues to
have diagnosed

wow a mazda engine in in a Toyota>? really?
20F (-6.66667 c)
or
20C (68f)
Big differ.. huh?
no year car sated
and worse? no engine option stated, cyl count and displacment.
and what country, each country uses unique EFI systems.

in cold weather diesel gels up and sometimes causes a no start issue..a cetane fuel additive helps with this issue. if temps go below 20 degrees, add a quart per tankful of cetane to the fuel to help start on cold mornings. also diesels require more amperage to crank than gas engines do..thus a stronger battery is needed..

Vehicle batteries tend to die during cold weather months since more amperage(power) is required to turn over the engine.


-----------------------obd2express.co.uk

easiest place to start is to stop at your local autozone parts house, or even some shops will scan your car and tell you what the code causing the light to come on for free.

Take it to a shop and have it scanned and see what the problem is. Then you will get an estimate for the repair or decide to try it yourself.

Is it a check engine light or Maintenance Required light? If its the maintenance required light, turn the car off, push and hold the trip odometer button while turning the ignition back on. Don't start the car. You'll see five dashes that will count down to none. That'll reset the maintenance required light. Do it after every oil change and it'll come on when its time for an oil change.

have you had the shift interlock checked or adjusted ...it may just be its out of adjustment ... that will give you both symptoms

Hi
From my expirience, this happens when any of the ignition coils is faulty (they do burn).
Find the faulty one and replace it, that will be the prob.
Thanks

Hi jmach,

There is nothing wrong with your vehicle and no need to have anything repaired.... The high idle speed is controlled by the on board ECU...(the Electronic Control Unit).... When starting the vehicle from cold, the automatic enrichment of fuel increases the idle speed... Depending on the ambient air temperature.... the colder the weather, the longer the engine will take longer to return to normal idle speed. Thats how it's designed to operate.

Regards Johngee10