Throttle Position Sensor Diagram: 4 Signs Of A Defective Sensor (Detailed Guide)

Carol Sylvia

October 25, 2022
7 min read

You might end up in a crash if there’s something wrong with your throttle position sensor diagram. Although this car component is small, it serves the whole mechanism and guarantees safe and enjoyable drives.

Yet, many car owners underestimate its uses and even lack basic knowledge about this crucial part. With that in mind, Driverevolve brings you a detailed throttle position sensor overview, a comprehensive guide on how to test it, and 4 signs of malfunctioning!

What Is A Throttle Position Sensor?

The throttle position sensor (TPS) tells the ECU which angles your throttle is at. Besides serving as the primary signal for calculating gasoline and ignition, this also helps in idling detection, deceleration monitoring, and adjusting gasoline and ignition procedures during sudden changes in throttle position.

This device’s output resistance changes in response to the throttle settings. Your ECU supplies the strips with 5V+ at one side, and a signaling ground on another, and the wipers send the data back to the ECU.

With a TPS, you should expect a resistance spectrum of about 200 ohms (0.2k) to approximately 4000 ohms (4k). The resulting voltage signal for the ECU begins at about 0.50V at the fully closed angle and rises to about 4.00V at the fully open position.

The Throttle Position Sensor Diagram

Throttle position sensor diagrams represent the electrical cables connecting the motor and other automotive parts.

Depending on the year, manufacture, and series, your throttle position sensor’s cabling may differ. The automaker will wire your throttle position sensor to its specifications.

Read the guidebook that comes with your specific model of automobile. The cables’ colors vary and are designated by the device manufacturer.

How Throttle Position Sensor Work

Typically, this device lies affixed to the throttle body. It can detect where the butterflies or throttle valves are at all times and relay that data to the ECU.

It measures the pressure applied to the gas foot and provides an electrical current reading as an output, regulating the machine’s air intake.

When your valve comes fully open, the motor draws a considerable volume of air, and conversely, when it is closed. The ECU receives the readings from this and other devices and uses them to determine the optimal fuel injection rate.

What Happens If You Disconnect Throttle Position Sensor?

Disconnecting your throttle position sensor (TPS) is risky and can cause severe damage to your vehicle. This disengagement will immediately affect your airflow temperatures, engine rate, and so on, resulting in motor degradation, poor gas mileage, a harsh idle, and performance loss.

Some sites, however, state that disabling your TPS improves the car’s performance. While there may be a deeper problem, you shouldn’t remove your TPS unless a professional mechanic tells you to.

Keep in mind that it may be against the law to alter or interfere with parts that reduce the ECU’s factory efficiency.

How To Test For The Correct TPS Wiring

If you have a TPS and aren’t sure how to configure it, you can quickly figure out the proper setup by running a few quick diagnostics. Everything you need is a multimeter with a resistance measurement function to carry out the tests.

Firstly, you’ll need to examine which wires are 5V and Ground; from there, you may use elimination to determine which lead is the Signal. With the Signal wire now recognized, we get a 2nd round of diagnostics that defines which one is 5V and which is Ground.

Identifying The Signal Pin

Recognizing the 2 other wires is the first step in finding your Signal wire. In other words, determine which two leads provide 5V and which provide Ground.

To execute this test:

Change the settings on your multimeter, so it reads in the kilohm range for Resistance.
Choose any 2 test wires on the TPS and position the leads, so they make strong, solid contacts.
Observe the resistance as you run your TPS across its whole range.
In the TPS paradigm, we are looking for resistance to changes. Choose a different pair of wires to examine if the resistance is fluctuating.
To find the 5V and Ground, look for the set whose resistance does not fluctuate.
Simply by elimination, the last wire is your Signal.

Identifying 5V and Ground Pins

Once we identify your Signal wire, we can locate the 5V and Ground pins. Here’s how to run the test:

Connect a multimeter tip to the Signal wire.
Examine the resistance by putting the other end to one of the other wires.
Check the resistance once more, this time with one tip on the Signal wire and the second tip on the very last lead.
The 5V line would have the least resistance of any of the others.
The Ground is the wire with the greatest resistance.

Calibrating the TPS In ESP

When you first connect a TPS to your ECU, whenever the throttle stops are adjusted, or whenever you reposition the TPS, calibrating is mandatory.

For the TPS calibration, you must be connected to your electronic control unit:

Click on Primary Settings / Devices / Throttle Position Sensor.
Navigate to the Calibration section.
To start calibrating, select Start and hit the button.
Make sure your throttle is 100% closed, then hit the Calibration icon to capture the exact voltage at 0% throttle position.
Once you’ve opened your throttle as wide as possible, push the Calibrate icon once more to save the voltage reading for 100% throttle opening.
If the readings reported for 0% and 100% TPS sound right, you can confirm your calibration by pressing OK.

4 Symptoms Of A Bad Throttle Position Sensor

The throttle position sensor within your automobile will clearly indicate if it is defective. If your car shakes when accelerating, it may be due to a bad throttle position sensor.

When it’s broken, the pressure on the engine is enormous, which may cause it to cut out. Even the transmission’s mount is vulnerable to damage.

Furthermore, look out for these common symptoms of a broken or malfunctioning throttle position sensor:

The vehicle either has no power to ramp up or speeds up on its own.
The motor dies suddenly or has an unsteady or sputtering idle.
Your car accelerates but won’t drive faster than a decently slow cruise speed and won’t shift gears.
In certain situations, the warning engine light will come up (as with a bad transmission speed sensor).

FAQs

Is A Throttle Position Sensor Necessary?

Sure, your engine control unit can’t properly schedule the ignition or keep track of gasoline use without a throttle position device.

TPS’s primary function is to maintain the ideal mixture of gasoline and air, as was explained above. As a result, the engine may overrun or die, creating a risky driving condition.

Will A Car Run Better If You Disconnect The TPS?

Actually, no.

Your ECU needs it to detect when your throttle is opened, or the gas foot is hit. If you leave your vehicle running after removing its batteries, it might chastise you. It may be difficult to start since it may function normally while idling, yet malfunction when the gas pedal is applied.

Furthermore, your engine may stall or splutter because the cylinders are confused by the sudden influx of air. If the diagnostic issue code for your throttle position sensor displays and the warning engine signal comes up, the driver might experience a change in the vehicle’s airflow.

In the worst case, a few automobiles won’t even start if the throttle position sensor is removed.

Wrapping Up

Understanding the throttle position sensor diagram will ensure you wire everything correctly and the device works its best, guaranteeing a safe and comfortable ride.

Indeed, any problems with your throttle position sensor can interfere with normal engine operations, seize the car, and in the worst case, cause a life-threatening accident.

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