Why These Three Car Warning Lights May Appear When It's Cold

Vehicle warning lights are meant to alert you to failures or problems in different parts of your car. Thus, it shouldn't be surprising that different warning lights are connected to different weather patterns because the weather has a great effect on your car. For example, here are some warning lights you can expect to light up when the weather gets too cold:

Low Tire Pressure

If your car is fitted with a tire pressure monitoring system (most new vehicles are), then the warning light will come on when the pressure drops below the recommended pressure. It doesn't take a big pressure drop to trigger the warning. For example, a pressure drop of 5 psi, which may be caused by a temperature drop of 50oF, is enough to turn on the light. Luckily, this is easily solved by adjusting the tire pressure.


The brake monitoring system deals with the parking brake and the brake pressure. Therefore, the brake warning light (NOT the ABS warning light for the antilock brake system) will come on when there is a problem on either of these two areas. For example, it may light up if your car is leaking brake fluid or the parking brake fails to release completely.

What has this got to do with cold weather? Well, moisture sometimes builds up in the brake fluid. If the temperature drops too much, then the moisture freezes and the brake fluid pressure balance is affected. The risk of this happening is higher in older cars whose fluids haven't been flushed for a long time. The solution depends on what is causing the warning light to come on; for example, if it is the issue of frozen moisture, then flushing the system will solve the problem.


If your car's battery is in a good condition and is operating as usual, then it isn't likely to freeze because a charged battery has an extremely low freezing temperature. However, cell damage, poor charging system or damage to the cells raise the freezing temperature by leaving the battery in a discharged state for longer. A battery in such a state may have the same freezing temperature as water.

Therefore, you need the intervention of a mechanic if the battery warning light comes on in extreme weather. The mechanic will check the condition of the battery system, such as the charging system and connections, and provide a suitable remedy.

Be on the lookout for these and other warning lights when the cold weather starts. Some of them may not be serious (such as low tire pressure), but some are and will cost you money. For example, if a frozen battery expands, it may cause a short between the plates and result in its permanent damage. To learn more about auto repair, speak with someone like Integrity Auto and Truck.