How To Reset The Throttle Position Sensor In A Toyota?

Your car, which was functioning OK the last time you drove it, is suddenly behaving strangely. It’s possible that the idle is surging, the car is jerking when driving, and it’s even possible that it stalls at a stop light. Your check engine light is most likely illuminated as well. This occurs when the throttle position sensor fails.

When this sensor isn’t working properly, you’ll notice obvious signs that affect the performance, or rather, lack of performance, of your vehicle. At the first hint of failure, this component must be reset or replaced.

To help you solve this issue, we are going to discuss how to reset the throttle position sensor in a Toyota. With no further ado, let’s get started!

What is a Throttle Position Sensor?

The amount of gasoline and air delivered to an automobile’s engine can be adjusted to influence the engine’s speed. This is accomplished through the use of a throttle system. The butterfly valve of the throttle system was previously controlled by a mechanical connection connected to the throttle pedal. When the driver depresses the accelerator pedal, the valve opens wide, allowing a large amount of fuel or air to travel through the vehicle, boosting its speed.

This procedure is carried out in current autos using the Throttle Position Sensor. The position of the throttle valve in automobiles was monitored by this sensor. It can also be thought of as a potentiometer that delivers varying resistance based on the throttle valve’s position.

Working principle

The throttle body is typically where this sensor is located. It detects the position of the throttle valve or butterfly valve and sends the data to the engine management unit. 

This sensor determines the position of the accelerometer pedal by monitoring how far down it is pushed. The engine’s airflow is controlled by where the pedal is pressed. A huge volume of air is delivered to the engine when the valve is wide opened, and vice versa. This sensor’s output, along with those of other sensors, is sent to the engine control unit, which determines how much fuel to inject into the engine.

A three-wired potentiometer is what this sensor is. The resistive layer of the sensor receives 5V power through the first wire. The second wire serves as a ground, while the third wire is attached to the wiper potentiometer and provides input to the engine control system.

Throttle position sensors are classified into three groups based on their structure. The throttle position sensors with built-in end switches, also known as Closed Throttle Position Sensors, the potentiometer type, and a mixture of the two types are the three types.

Signs of a Bad Throttle Position Sensor

1. Acceleration issues

A faulty throttle position sensor indicates that the engine control unit is unable to correctly manage the throttle position. Because of this, the engine will not be able to receive the necessary amount of air. When you try to accelerate your vehicle in these conditions, it will be extremely slow.

If you can get the vehicle moving faster than 30 miles per hour, you’ll be lucky. This might result in you consuming a lot of gasoline, resulting in your car’s fuel economy being ruined.

2. Unstable engine idle

When you come to a complete stop or park your car, the idle RPM should be between 600 and 900 RPM. If you see the engine RPM dropping or rising outside of that range while your car is stopped or parked, you have a harsh or unpredictable idling problem.

If you’ve had any of the other symptoms on this list, it’s possible that you have a malfunctioning throttle position sensor.

3. Abnormal fuel consumption

Poor fuel economy will be one of the unavoidable defective throttle position sensor signs, as indicated above, due to the engine’s inefficiency. The throttle position sensor works in tandem with other sensors to ensure that the engine receives all of the information it requires to run properly.

When these sensors fail, the computer in your automobile receives the wrong data, which causes your engine to receive inaccurate inputs. Different parts try to adjust for these discrepancies in different ways.

If the engine receives more air than it requires, the computer will adjust by injecting additional fuel to equalize the air-fuel ratio. As a result, when your sensor fails, your car will often consume significantly more fuel than usual.

4. Switching gears can be difficult

Automatic gearbox shifting issues might occur if the throttle position sensor malfunctions. The throttle position sensor is critical for proper automatic transmission control since it determines the driver’s intent and sends that information to the Transmission Control Module quickly. You’ll suffer delays and/or problems switching gears if the data isn’t transferred correctly and on time.

5. Warning light

When it comes to internal combustion engines, the throttle position sensor is critical. If this sensor fails, your engine will eventually be unable to create enough power to meet your acceleration requirements.

When this problem occurs, the engine control unit will detect it and illuminate the Check Engine warning light on the dashboard. You’ll be aware that your engine has a problem that needs to be treated in this manner. P0121, P0122, P0123, P0124, P2135, and P2138 are some of the most common diagnostic trouble codes associated with the TPS.

6. Engine stalling or trembling

Instead of outright failure, the TPS may cause the engine to stall or surge while it tries to send the proper fuel and air mixture. Your automobile may tremble as though it has an engine knock if you have a defective TPS.

How to Reset the Throttle Position Sensor in a Toyota?

Initial throttle sequence

The approach we’ll go over doesn’t require any tools, and it can be extremely useful when your Toyota’s battery dies or requires a jump start. The following are the procedure’s step-by-step instructions:

  1. Start by turning on the engine and inserting the key into the ignition
  2. After starting the engine, turn it off within a few seconds
  3. The steps above must be repeated numerous times
  4. Now start the car and release the parking brake
  5. Make sure the lever’s gear is set to drive, and then wait for a few moments

Pro-tip

Make sure the engine is adequately warmed up and ready for the next steps before beginning the procedure.

Second throttle sequence

This method requires no warming up and works exceptionally well for Toyota Tacoma models made between 2005 and 2015. This method’s steps are as follows:

  1. Start by turning on the engine and inserting the key into the ignition
  2. Do not restart the engine this time
  3. Now place your foot on the gas pedal and slowly press it down
  4. Hold the position for 3 to 4 seconds before slowly releasing the pedal
  5. Rep the previous stages at least three to four times more
  6. Remove the key from the ignition and wait for at least 5-10 minutes in the car

What Should You Do If None of the Above Solutions Work?

Depending on the model of your car, different things happen. Because your TPS is different from the others, you may not be able to employ any of the approaches listed above right now. If this happens, you’ll have no choice but to have your car diagnosed by a specialist. When you take your automobile to a mechanic, you won’t have to worry about the TPS being replaced; it can, however, be changed. However, if your TPS isn’t replaceable, you’ll have to buy a new one.

If you don’t, your car’s engine will suffer as well as its fuel economy. Sensor replacement is a time-consuming task that necessitates specialist understanding. As a result, it is suggested that the mechanic take on the project. If you don’t have the funds to pay for a repair, though, you can learn how to do it yourself by following the next section.

How to Replace Throttle Position Sensor by Yourself?

Sensor removal

To replace your sensor, follow these instructions. Determine where the sensor is located first. It should be attached to your engine’s throttle body, which is located on top.

Before removing the sensor, make sure you detach the negative battery cable. This reduces the risk of electrical shock and prevents the engine control module from displaying an error code. Using electrical connectors, connect your throttle position sensor. Using the tab on the side, these connectors are easily removed.

Look for mounting screws on your sensor once the electrical connectors have been removed. Remove the throttle position sensor by unscrewing it carefully. When shopping for a new sensor, make sure to read your owner’s manual and compare it to your old one. Find a high-quality brand or an exact OEM match at your local car parts store.

Throttle position sensor replacement

Work backward through the removal steps to install your new sensor. To begin, use the mounting screws to secure the sensor in place. After that, use an electrical connector to link your sensor to your vehicle’s electrical system. You should easily be able to press it together and hear a definite click. Verify that the connection is secure.

Prepare to double-check your work after connecting your battery. Test the idling and acceleration of your car by starting it up. You may need to tweak the sensor manually, depending on your car and the sensor you’ve installed. Other settings adjust automatically to provide your automobile with the right amount of air and fuel for a smooth idle and quick acceleration.

Looking for these indications can help you avoid expensive engine repairs, poor fuel efficiency, or exponential damage to your car, whether you follow these installation methods or have your local mechanic replace your throttle position sensor. When these problems appear, inspect your throttle body to see if it needs to be reprogrammed, repaired, or replaced.

Frequently Asked Questions

Is there any mechanism that could assist me in testing my TPS?

Yes, you may examine the quality of your TPS using a method. In this circumstance, you must turn the key, but you must not start the engine. 

Take a look at your dashboard’s multimeter readings right now. A voltage value of 1.5 to 2 volts is considered positive. Your TPS system is, to put it mildly, rock-solid. Reopen the throttle plate and examine the voltage measurement; if it climbs by 5 volts, your TPS system should be checked. This is the following step.

Is it still possible to drive my Toyota with a faulty TPS?

You can drive your Toyota even if it has a defective throttle position. According to us, it’s not a terrific idea. It’s also dangerous to drive a car with a low TPS. When you press the gas pedal to accelerate, you risk hitting something.

When the vehicle accelerates, you may not even be pressing the gas pedal, even if you aren’t trying to slow it down. Negative TPS should not be overlooked because it can lead to unfavorable outcomes.

What could be the reason for a TPS code?

If the TPS often drops below a predetermined voltage range, there is a TPS code. The problem could be caused by a TPS that is only loosely attached. The TPS in your car is broken, or the TPS switch is broken. On the TPS, the ground wire or any other circuit wire could be shorted out (circuit).

How much does a TPS cost to replace?

The throttle position sensor costs between $110 and $200 to replace on average. The cost of the parts is from $75 to $105, and the cost of labor is between $35 and $95.

You’ll also need to factor in any additional fees or taxes. Overall, this replacement project shouldn’t cost more than $250. You might be able to get a reduced hourly fee if you look for a cheap mechanic.

Conclusion

This is it! Now that you know how to reset the throttle position sensor in a Toyota, your car should accelerate smoothly and retain optimal fuel economy if the throttle position sensor is functioning properly. When it fails, though, it becomes a safety concern that must be addressed immediately.

Liam

Hi, I'm the initiator and writer of this blog. Cars were and will be my first love, and my favorite hobby, that's why I decided to start this blog and write about my discoveries and techniques to improve my cars or repair them.