As a BMW owner, few things are more stressful than when your “check engine” or transmission warning lights come on. Since these lights don’t give you any explanation about what’s wrong, it’s difficult to troubleshoot on your own. Sometimes, the problem is caused by something that is simple and easy to fix. Other times, it’s a major issue. Regardless, if either of these lights comes on, it’s best to have it checked out by a skilled BMW technician right away. Here’s a look at some of the most common problems BMWs face when the engine and transmission lights come on.
Loose Gas Cap
In the best-case scenario, you may just have a loose gas cap. Since your gas cap seals your fuel system, when it’s loose, it can alter the fuel system’s internal pressure. This will reduce your gas mileage and can increase emissions from your vehicle.
If your check engine light has come on, the first thing you’ll want to do is check your gas cap. In some cases, tightening it will fix the problem. If the cap is damaged, you’ll want to replace it. As long as this is what was causing the problem, the light should go off once it’s fixed.
Faulty Oxygen Sensor
Your oxygen sensor ensures your engine is working correctly by monitoring the exhaust for unburned oxygen. If the sensor fails, it will send incorrect data to the computer system, which could cause the check engine light to come on. In this case, replacing the sensors should fix the problem.
Note that this is a time-sensitive issue. If you don’t get it fixed, it could damage your catalytic converter. This will result in a far more expensive repair down the line.
Failing Catalytic Converter
A failing catalytic converter is a serious problem that can cause your check engine light to come on. This can affect your gas mileage and cause your vehicle to fail emissions tests. Eventually, your vehicle won’t be able to accelerate.
If the catalytic converter completely fails, your car won’t work at all. This is a very expensive repair, so it pays to have this taken care of as soon as possible.
Bad Spark Plugs
Spark plugs simply wear out over time and there’s no way to keep them from failing. If this happens, your check engine light may come on. Luckily, this is an easy fix. A mechanic can do it quite quickly and it’s usually an affordable repair. If you wait too long, however, it could create other problems, so make sure to get this taken care of right away.
Faulty Mass Airflow Sensor
An issue with your mass airflow sensor is another common problem that can trigger your check engine light to come on. This sensor tells your BMW’s computer system how much fuel to add based on the flow of air that’s coming through your engine. When these sensors start to fail, they can cause your vehicle to stall. This can also cause your gas mileage to decrease and your emissions to increase.
You can continue driving with this issue, but it’s not a good idea. Not only is frequent stalling inconvenient, but it could also create other problems with your vehicle.
Low Transmission Fluid
If your vehicle is low on transmission fluid, it can cause your transmission to overheat. When the temperature of your transmission fluid gets higher than it should, your transmission warning light will come on. BMW transmissions are extremely expensive to replace, so it’s important to have this issue checked out by a qualified BMW transmission repair specialist as soon as possible.
It’s also important to note that while your vehicle may not drive any differently when the light comes on, extensive damage could still be occurring. Left too long, this may significantly reduce the lifespan of your transmission.
Software Issues
BMW often issues software updates for their vehicles’ automatic transmissions. The purpose is usually to improve shifting by changing the shift points. This can sometimes cause your vehicle to go into SAFE MODE or create erratic shifting problems.
Your BMW mechanic will be able to find out whether a software issue is causing your transmission light to come on and fix the problem for you.
Sensor Malfunction
It’s possible that your transmission warning light has turned on due to a sensor malfunction. You could also have some type of electrical issue that has triggered the warning. This could be a simple fix or an indication of a larger issue.
Need a Trusted BMW Technician? Contact The Haus
As you can see, waiting to deal with a check engine or transmission warning light can often create bigger (and more expensive) problems. If either of these lights has come on, it’s a good idea to call a qualified BMW mechanic right away.
The certified technicians at The Haus are experts in BMW transmission issues and engine maintenance and repair. We also have two convenient locations to serve you. If you’re having an issue with your BMW or it’s time for your routine maintenance, contact us today to schedule a VIP appointment.