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Black BMW M4 Car

When To Fix Your BMW Throttle Position Switch

by Mechanics Direct March 3, 2024

Is your BMW struggling to pick up speed? One possible explanation is a defective throttle position switch (TPS). As a crucial part of a vehicle, the TPS plays an important role in regulating airflow into the engine. If it breaks, a slew of issues will emerge — including: malfunctioning lights, sluggish acceleration, and bad mileage. This blog post shares signs your sensor has expired, possible causes, along with ways to diagnose and address the problem directly.

Throttle Position Switch (TPS) In A Nutshell…

Mounted on the throttle valve spindle, the TPS helps the engine management computer (ECU) keep track of throttle valve behavior, including movement and position. Based on real-time inputs it receives through a network of sensors (i.e. oxygen sensor, airflow temperature sensor, and engine speed sensor), the ECU controls spark plug firing and balances air-fuel proportion inside the combustion chamber. Meaning, data from TPS helps the ECU manage different aspects of engine operation. A problematic TPS may trick the ECU into spraying more fuel into the combustion chamber that may contribute to a multitude of problems.

Signs Your BMW’s TPS Has Expired

#1- Malfunctioning indicator light

When more fuel is injected into the combustion chamber, inaccurate data is created. Sometimes, destabilized air-fuel mixture inside the cylinder may prompt the engine to behave erratically and turn the check engine light on. So, if your BMW’s dashboard warning is lit up, its torque output has dropped drastically. Make sure to have a professional check its current throttle position switch.

#2- Slow Acceleration

A defective TPS may also contribute to acceleration-related issues in a vehicle. If you experience difficulty achieving your desired acceleration, it could be due to the ECU getting erroneous data and battling to balance the air-to-fuel proportion. In this case, act promptly and have the issue diagnosed. If you don’t, it may worsen to your motor stalling, rough idling, and misfiring.

#3- Bad mileage

Along with vehicle performance, a broken TPS may adversely impact its mileage. By destabilizing the air-to-fuel proportion inside the cylinder, the engine management computer may be prompted to use with more fuel than what’s actually required. Keep an eye out for an unexpected jump in your gas consumption rate.

#4- Rough engine idle

Ultimately, if your TPS is faulty, you’ll experience a rough engine idle. Since the ECU won’t be able to monitor the throttle valve’s position, it’ll struggle to maintain a steady idling speed. However, watch for defective idle air control valves, carbon fouled spark plugs, and clogged fuel injectors to see if there’s an alternative cause.

#5- Trouble shifting gears

Due to the fact that the transmission control module relies on real time data from the TPS and other sensors to oversee different aspects of gearbox operation, you’ll have trouble shifting gars if there’s something awry. If for some reason your BMW’s TPS fails, shifting gears in will be daunting.

BMW TPS Failure- Discussing Leading Reasons

Just like other electrical components of your BMW susceptible to problems and failure, the TPS is the same way! There are several prominent reasons why this failure occurs in cars:

  1. Has reached its maximum serviceable life
  2. Bad wiring or a blown fuse
  3. Electric short circuit
  4. Installation error
  5. Accumulation of dust, debris, and other foreign elements

BMW Throttle Position Switch Check

Go-to Service Center In Lowell For All Your BMW Problems

A defective throttle position switch, if not replaced on time, can contribute to an array of drivability issues in your BMW. So, if you suspect a TPS glitch in your car, visit to the nearest service center at your earliest convenience. Residents from North Chelmsford, Chelmsford, Dracut, Tyngsborough, Westford, and Lowell, MA, can reach out to us directly for assistance! At Mechanics Direct, our facility has certified and experienced professionals who can diagnose and address any throttle system issue in your BMW, especially a defective TPS. Call now or go online to book an appointment today!

* Black BMW M4 Car image credit goes to: Brandon Woyshnis.