Before TPMS sensors were available, the only way to tell if your car had a flat was based on how it drove.
You might lose some control over the vehicle, hear a thumping noise, or be unable to move.
BMW offers a tire pressure monitoring system that alerts drivers when it senses changes to this reading that indicate a possible flat. The warning displays when a tire’s PSI is 20% below the recommended amount.
The easiest way to remove the warning is to re-inflate the affected tire. What happens if all the tires are already at their recommended PSI and you get a TPMS warning?
Troubleshooting BMW TPM (TPMS) Malfunction
The TPMS (Tire Pressure Monitoring System) on BMW vehicles alerts drivers when the tire pressure is too low. It malfunctions when the sensors reach the end of their service life, which is between five to seven years. Outdoor temperature changes and road conditions also cause it to display.
BMW includes the universal symbol for a tire pressure issue on the drive display. It looks like a tire with an exclamation point in the middle. Most makes and models include this HUD warning if they have a tire pressure sensor.
Drivers will see a warning message displayed with the yellow symbol. An audible sound warns that there is low pressure to correct. It appears between the speedometer and the RPM gauge in front.
The BMW system lets you see with specificity what tires are affected by the problem. You’ll also see text telling you where the problem is and how to correct the situation.
If you think that a TPMS malfunction occurred, you can perform a reset after the warning. Should the same issue arise after you’ve physically inspected the affected tire(s), you’ll likely need to replace the pressure sensors to correct this issue.
The other two issues to examine are an RDC module fault or external interference.
What Should I Do if I Get a TPMS Warning?
When you receive a tire pressure warning, you should pull over immediately to inspect your tires.
Your Drive Display might show that you’ve got 25 PSI in one tire while the others are inflated to the correct pressure.
Pulling over is still the best option because it allows you to inspect the tire to determine if damage or a leak is happening.
If the pressure loss is minimal and no leaks are detected, continue driving to the nearest service station or convenience store.
Use an air compressor to restore the missing air to your tires. You’ll find the recommended PSI ratings on the label placed on the driver’s door frame. It’s also behind the gas cap.
Most BMW vehicles have a recommended tire pressure of 32 PSI to 36 PSI. If you’re driving with low-profile tires, you might need to fill them up to 45 PSI.
Should the tire be damaged, you’ll need to have it repaired to determine if there is also a TPMS malfunction. If your readings all look good, you’ll be ready to reset the warning.
What Error Messages Will I Receive with a TPMS Malfunction?
When your tire pressure monitoring system isn’t working correctly, it will attempt to inform you of this fact. You may see one of several messages appear while operating the vehicle.
- Tire Pressure Monitor Reset. This message indicates the TPM system is inactive and cannot detect pressure loss. It takes up to 12 minutes for it to reset, and you must be driving to accomplish that result.
- Tire Pressure Monitoring Malfunction. In this situation, you’d want to review your tire PSI readings manually. If you don’t detect a problem, drive carefully until you can reach a service center. The system stops reading tire pressure loss with this problem.
- TPM Inactive Warning. This warning is displayed on the dashboard. It appears when the system is unable to detect pressure loss, or a PSI drop is detected. Continued driving is possible if you’ve verified that your tires are in working order.
If your BMW vehicle has designated run-flat tires equipped, you can continue driving without the appropriate PSI for up to 50 miles. The goal is to reach a service station where the issue can be repaired.
The tires must have the RSC symbol on them to take advantage of that feature.
How to Reset a BMW TPMS Malfunction
After you’ve added more pressure to your tires, repaired a problem, or discovered that an issue doesn’t exist, the next step is to reset the TPMS warning on your BMW.
Here are the steps to follow to have a successful experience.
- Press the iDrive knob so that you can choose your vehicle settings.
- Scroll until you see the option for the car’s tires.
- Rotate the know so that you can select the tire pressure monitoring menu.
- Choose the reset option, then press the iDrive knob.
- You’ll get asked if you want to take this step. Select “Yes.”
- You should see the status change to “Resetting TPM.”
After taking a short drive, you should see the status change to an active state.
The United States requires vehicles from the 2008 model year and on to have a tire pressure monitoring system installed. All BMW vehicles have this feature, regardless of the equipment level, trim, or model.
When you reset your TPMS, any loss of tire pressure during that process cannot be detected by the sensors.
The goal is to keep your tires at the proper pressure to ensure they perform as expected and provide the fuel economy needed for an extended life.
What Do I Do if the Light is Flashing?
If you’ve encountered a flashing light with your TPMS, it means that the monitoring system has become disabled. That means it’s time to put on a figurative detective’s hat to determine what is causing the malfunction.
Here are the common problems that cause this circumstance to develop.
1. Defective RDC Transmitter
If you have an older BMW, the first two generations of the tire pressure monitoring systems have sensors within each tire and wheel well.
Transmitters pick up the signal from each sensor to send over to the vehicle’s central control unit.
As the vehicle ages, the transmitter stops functioning. This issue causes communication to start breaking down within the system, causing the warning light to appear.
You might find that a reception antenna in the control unit failed to cause this issue.
2. Water Damage
BMW vehicles equipped with a third generation TPM system use a single control unit with an integrated antenna.
Some models have this equipment mounted to the chassis. That exposes it to your daily driving conditions, which means moisture can get into the casing and start corroding the sensitive electronics.
Even though this control unit is sealed, you can open it with a little elbow grease. If you spot any corrosion traces, which are usually colored green, you can often correct the malfunction.
Some modules are installed under the driver’s side dashboard or the spare tire. When your BMW has the latter, there’s a known issue where water can build up underneath the mount, causing damage to the RDC module or contact corrosion.
3. Defective TPM Fuse
All fuses can burn out if a short occurs. This issue happens when the control unit has a problem or power surge in BMW vehicles.
Most models have their fuses located in the junction box right behind the glove compartment. You’ll need to unclip to cover to inspect them.
Underneath the cover is a map of what fuses are associated with the various systems. Find the one for the TPM in that grid, then look to see if you see any scoring. It usually looks like brown or black streaks on the sides or bottom.
If the fuse needs to be replaced, just pop the old one out and put the new one in to correct the TPMS malfunction.
4. TPM Sensor Battery Problem
Each tire offers a sensor that delivers information about the air pressure to the TPM system. BMW uses lithium-ion batteries to provide this data.
An OEM product can last for up to ten years, but it’ll eventually need to be replaced because it is a consumable product.
If you recently purchased new tires for your BMW, a fitment problem could cause the TPMS problems you’re encountering. The sensor would need to be replaced in that circumstance.
A wireless reader can help you verify if the sensors are still emitting signals. Many tire shops offer a free diagnosis if you think this problem is the cause of the malfunction.
How to Diagnose a TPMS Malfunction in a BMW
You’ll need to have a BMW-compatible scanner that will help you read and clear the specific fault codes that occur with this problem.
If you use a generic OBD-II scanner, it will read problems with the wheel electronics, the transmitter, or the RDC system malfunctions.
That’s why I prefer to use the ANCEL Full Systems Diagnostic Scan Tool. It provides support for OBD-I and OBD-II while having an expanded lineup for BMW vehicles.
You can use it as a professional resent tool while reading the codes for other non-BMW vehicles you might have at home.
This tool guides you through the simple steps that let you take care of basic maintenance tasks, such as resetting the service light, oil service needs, and fuel injector adjustments. You have full access to the complete diagnostics set with free lifetime updates.
It’s a simple and hassle-free way to manage your TPMS malfunction while having resources that help you manage other vehicle maintenance and repair tasks.
How Soon Should I Address a TPMS Malfunction?
A TPMS malfunction makes it more challenging to detect a tire pressure issue. If the tires maintain adequate PSI, it is possible to continue driving. Operators would lose the benefits of monitoring this performance indicator, leading to a potential drop in fuel economy or the complete loss of pressure.
I was minding my own business, taking the interstate home after a long shift at work. It’d been a tough day, and I was looking forward to some quality time with my television.
Suddenly, a huge bang erupted from the front of my vehicle. The TPM warnings came on, with the alarms sounding brightly. I had virtually no control.
Thankfully, an exit was right there. I cut across three lanes of traffic, got to the shoulder, and couldn’t go further. When I got out, I discovered that both front tires had shredded.
After a long walk down the ramp since my cell didn’t get a signal there, I scheduled a tow and waited.
It took a couple of hours to get to the shop, find some tires, and get me back on the road. That’s when the TPMS malfunction happened.
It took four months to correct the problem. Even though everything tested fine, including the fuses, there was a slight displacement issue with the battery. I went back, got a better fitment, and life finally got back to normal.
A TPM malfunction isn’t a serious issue in most circumstances, but it could be. That’s why it pays to have this issue thoroughly inspected.
