When the DME module in a BMW vehicle detects a problem, it produces the Engine Malfunction Reduced Power message on the iDrive screen. This issue can also cause the check engine light to appear.
You can determine how serious the problem is by looking at the color of the warning light. Red tends to be the most severe, while bright yellow is more of a caution.
Since several problems can trigger this message or warning display, it is crucial to have a correct diagnosis before starting the repair.
BMW Engine Malfunction Reduced Power
When the check engine light or Engine Malfunction Reduced Power error message appears, it is usually a problem with the battery. You might see the Battery Indicator light up, especially if a faulty connection exists. An OBD-II Scanner is the best way to determine what problem exists.
BMW vehicles produce a unique set of error codes compared to other automakers. That means your OBD-II scanner must be programmed with the information your vehicle creates to diagnose the engine malfunction problem.
The AUTOPHIX Enhanced BMW Full Systems Diagnostic OBD-II Scanner provides the special functions needed to read the error codes. It works for all models built after 1996. It uses a straightforward control mechanism beneath an oversized display to help you navigate to each setting.
If you own a BMW and another vehicle, you can use the standard OBD-II function and the specific menus for the BMW to maximize the versatility of this helpful tool.
It reads all major systems and fault codes for common problem areas. That includes your TPMS, SRS, SAS, ABS, and fuel pump reset. If you receive a note to change your oil, you can reset it with this device.
When the Engine Malfunction Reduced Power message occurs, the AUTOPHIX diagnostic scanner lets you see what is wrong so that an appropriate repair occurs. It connects to the port found under the dashboard on the driver’s side.
Signs and Symptoms of an Engine Malfunction Reduced Power Problem
When you see the Engine Malfunction Reduced Power message appear on your iDrive screen, it usually happens when one or more of the following symptoms are also happening.
- You have noticed a reduced acceleration output compared to how the BMW usually drives.
- The transmission switches itself into limp mode as a safety precaution.
- Less engine power is available in each gear.
- Your vehicle no long passes an emissions test, or you notice more smoke or exhaust gases coming through the system.
- The drivetrain malfunction warning light and message display.
- Your check engine light displays on the heads-up display.
It is possible for the Engine Malfunction Reduced Power message to appear without any noticeable symptoms.
If you receive this warning or a light appears on the dashboard, it’s important to review the error code to determine what issue or problem triggered the notification.
What Does It Mean When the Engine Malfunction Reduced Power Problem Occurs?
The Engine Malfunction Reduced Power message typically occurs when the vehicle purposely limits performance for a specific reason. When it activates, the most common symptom is a failure to accelerate as expected.
Even if you don’t see power reductions right away, the overall performance could be limited the next time you attempt to drive the car. Depending on the situation, the warning could even cut fuel to the engine to render it undrivable.
By creating a failsafe mode that activates automatically, the goal is to prevent additional damage from happening when systemic failure occurs.
Common Issues That Cause the BMW Engine Malfunction Reduced Power Message
Several potential issues can cause a BMW vehicle to display the Engine Malfunction Reduced Power message or cause warning lights to appear.
One or more of the following problems could exist. That’s why a thorough inspection and a complete diagnostic evaluation are necessary when this message or warning appears.
You’ll get an idea of what to expect when connecting an OBD-II scanner to the port, but some cars might provide an incomplete picture of the repair needs.
It may be necessary to get your eyes on each component to see if it functions as expected.
1. Valvetronic Throttle System
Valvetronic is an innovative system developed by BMW that offers variable valve timing. Drivers receive precise and continuous control as it delivers variable intake valve lift. With the second and third generations of this system, you receive 0.18 to 9.9 mm, while the first generation provides 0.3 to 9.7 mm.
The Valvetronic system typically works with the independent VANOS system to continuously vary the timing for the intake and exhaust camshafts.
The engine relies on the amount of valve lift to manage its load control instead of using a butterfly valve.
When it malfunctions, you’ll notice a lack of power and possibly poor throttle response. The system is remarkably complicated, so multiple failure points exist.
You’ll need to check each one, although the shaft position and electric motor sensors tend to be the biggest culprits of the Engine Malfunction Reduced Power message.
If you have an OBD-II scanner to use, the error codes for a Valvetronic problem are 2A61, 2A63, 2A67, 2A6F, and 2A70.
2. VANOS System
When driving a BMW, the oil-powered actuators in the engine compartment operate VANOS. It’s a straightforward design built with robust durability, but it can fail if too much sludge builds within the system’s solenoids.
The most common reason for this problem is not sticking to the recommended service schedule for the vehicle.
Although regular cleaning and oil changes can help, the solenoids do fail more often after 70,000 miles. When you experience this issue, the Engine Malfunction Reduced Power message typically appears.
You might hear knocking or tapping noises coming from the engine while idling or driving.
After connecting your OBD-II scanner to the port, you’ll see error codes 2A82 or 2A87 appear if an issue exists with VANOS.
3. Oxygen Sensor
BMW uses upstream oxygen sensors to produce readings that optimize the engine’s performance. When they don’t function as expected, it’s relatively common to see the Engine Malfunction Reduced Power message appear on the iDrive screen.
The most common reasons for these sensors to stop functioning as expected involve excessive oil or fuel consumption. It’s also possible for a loose connection to develop or damage to occur to the wiring.
You may receive a yellow check engine light when the oxygen sensor fails.
The repair is relatively straightforward, swapping out the damaged component for a new one. If excessive oil or fuel consumption led to its failure, you’d want to have a thorough diagnostic for your BMW to ensure another issue isn’t impacting the vehicle’s performance.
After plugging your OBD-II scanner into the port, you’ll see error codes 2C9C, P0171, P0172, P0173, or P0174 appear to indicate this issue.
4. Ignition Coil
An ignition coil can fail for multiple reasons. When it does, a misfire typically occurs. You might notice your BMW start to shake when accelerating, especially with the pedal to the floor.
An occasional misfire or a one-time event might not trigger the Engine Malfunction Reduced Power message. When it occurs frequently, you’ll want to stop driving as soon as possible to diagnose the issue.
When BMW engines misfire, they can cause significant damage to the catalytic converter.
Ignition coils are relatively easy to replace, even for those who don’t work on cars often. The Bosch OEM part is an excellent choice, and it’s helpful to have them on hand because of how common this issue occurs.
When you hit a good bump in the road or experience unexpected vibrations, it is possible for the ignition coil connection to become loose. Tightening it should solve the problem, but you’ll still need to clear the error code with the OBD-II scanner.
Codes P0300 to P0306 display when you have an ignition coil issue responsible for the Engine Malfunction Reduced Power warning.
5. Timing Chain
Older vehicles used a timing belt that would typically wear out after 100,000 to 150,000 miles. New models went to a chain to offer more durability. It’s intended to be a lifetime item for the engine, but there can be times when malfunctions or damage occurs.
Some chains can have their links stretch after long-term use to trigger the Engine Malfunction Reduced Power warning message.
It’s also possible for the plastic guides or tensioner to fail, causing the component to jump three teeth or more.
If you experience a problem with your timing chain, the most common symptom is a rattling sound from the engine. You’ll also get the same error codes that a VANOS problem creates.
When you get a red check engine light with a timing chain problem, the jump is usually more than three teeth. An immediate repair is necessary, and your engine should not be restarted until the issue is addressed.
6. Battery Problem
When your BMW’s battery becomes underpowered to meet the vehicle’s needs, the Engine Malfunction Reduced Power message can appear on your iDrive screen. All batteries lose energy as they get older. Once a certain threshold is reached, a replacement is necessary to maintain functionality.
Anyone with a battery more than seven years old should replace it if they encounter the malfunction message.
You can clear the error codes and restart to determine if this issue was the cause when there isn’t a red check engine light associated with the message.
Do not restart a BMW engine if you see a red check engine light.
It might not be the battery causing the issue. If your charging system isn’t working, you’ll see the vehicle react similarly.
A replacement part is necessary to restore functionality if the alternator goes bad, which can take some time to repair.
7. High-Pressure Fuel Pump
If you have a BMW 335i E90 or newer vehicle, your engine comes with high-pressure fuel injection as a feature. It’s a delicate system that experiences damage when using low-quality gasoline to power the car.
When you experience the Engine Malfunction Reduced Power warning, it is usually the injector or the fuel pump that serves as the failure point.
This problem causes the engine to crank longer and harder before ignition occurs. You might have a rough idle develop, and the yellow check engine light could appear.
If your car does start, you might notice acceleration and power output problems. The only way to correct this issue is to replace the malfunctioning component.
You’ll see error codes 2FBA, 2FBF, 29DC, or 29E2 if an issue with your high-pressure fuel pump or the injectors is responsible for the engine malfunction message.
If you drive a BMW equipped with a single or twin-turbo design, such as the N54 or N55 engine, this component could be responsible for the Engine Malfunction Reduced Power message. It will feel sluggish while accelerating while having reduced power.
Several issues can cause the turbos to stop functioning as expected. It could be a broken vacuum line, malfunctioning solenoids, or cracks in the piping between the intake manifold and the intercooler.
The clips that hold the rubber hoses in place have a reputation for slipping or breaking, which causes the hose to disconnect. Replacing them can often repair the problem.
You might have a wastegate stuck in the open position or a blowoff valve leak causing boost problems.
Your OBD-II scanner will show you a 30FF error code if you have a boost leak.
Can I Fix an Engine Malfunction Reduced Power Warning?
The only way to diagnose a malfunction with a BMW engine is to have an OBD-II scanner equipped with the automaker’s error code library. When drivers see the fault codes produced by the DME module, it is easier to recognize and repair the problem that triggered the warning message.
Although the Engine Malfunction Reduced Power message can be scary when you see it, the repairs are typically simple and straightforward. It could even be due to a loose connection.
When you have the AUTOPHIX Enhanced BMW Full Systems Diagnostic OBD-II Scanner available to read the error codes produced by the DME module, you can make decisions with certainty because you have the necessary information available.
If you’re unsure of how to replace or repair a specific component, please consult with a trusted mechanic or work with your local BMW dealership to ensure your warning message or light gets resolved.