During your normal driving, consider inspecting your sensor if you experience any of these throttle position sensor symptoms:
- Hesitations during acceleration
- Poor power
- Difficulty and/or delay in gear shifting
- Unusual surges while accelerating
What are the symptoms of a bad throttle position sensor?
What Are the Symptoms of a Bad Throttle Position Sensor?
- Rough Idle. An engine at idle will be spinning at roughly between 600 and 900 rpm. ...
- Weak or Erratic Acceleration. A failed throttle position sensor can have a significant effect on how your car accelerates when you hit the gas pedal.
- Poor Fuel Economy. ...
- Check Engine Light Is On. ...
How can you tell if throttle position sensor is bad?
How can you tell if throttle position sensor is bad? Below are several key signs of a bad throttle position sensor. One of the telltale signs of throttle position sensor problems is slightly delayed acceleration. If you notice a delay between the time you press on the gas pedal and the time the vehicle actually accelerates, take the car ...
How to diagnose a throttle position sensor?
- An unexplainable bucking and jerking in the vehicle
- Sudden idle surges
- Sudden engine stalling without any apparent reason
- Hesitation while accelerating
- Sudden surges in speed while driving on the highway
- Intermittently flashing of check engine light for no apparent reason
- Difficulties in changing gears
- A drastic drop in fuel economy
What happens when the throttle position sensor is bad?
When a throttle position sensor goes bad, your vehicle may stall or run rough at idle, and may stumble upon acceleration. The replacement of the TPS is a straightforward procedure that should take an amateur mechanic less than an hour to complete.
What happens when throttle position sensor goes bad?
What happens when my throttle position sensor goes bad. When a TPS goes bad, then the car's throttle body won't function properly. It could either stay shut or it won't close properly which is a severe issue. If it stays shut then your engine is not going receive air and it won't start.
How do you know if your throttle position sensor is bad?
Symptoms of a Bad or Failing Throttle Position SensorCar won't accelerate, lacks power when accelerating, or accelerates itself.Engine won't idle smoothly, idles too slowly, or stalls.Car accelerates, but won't exceed a relatively low speed, or shift up.More items...•
How do you reset the throttle position sensor on a GMC?
The easiest way to reset your throttle position sensor is to unhook the negative cable from your battery for up to five minutes or to remove the fuse for your engine control module.
How do you check a TPS sensor on a GM?
1:017:12How to test TPS sensor on any GM throttle position sensor - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo then you want to take your throttle or get somebody in your car and move the gas pedal veryMoreSo then you want to take your throttle or get somebody in your car and move the gas pedal very slowly. And what you want to see is a steady increase all the way up to about almost five volts.
Will a bad TPS throw a code?
a faulty tps can set a trouble code in the computer if the voltage value is either not present, sporadic, slow or constant, and this can illuminate your check engine light.
Can a bad throttle position sensor affect transmission?
The Throttle Position sensor measures the throttle position, which is controlled by the gas pedal. It is used to determine engine load and if it fails it can cause automatic transmission shifting problems.
Do you have to reset computer after replacing throttle position sensor?
After replacing the throttle body to your engine, if the engine light was on and has a pending code, the code will go away. If the code was a hard permanent code, then the ECM (computer) would need a hard reset.
How much does it cost to fix a throttle position sensor?
The average replacement cost for the throttle position sensor is anywhere from $110 to $200. The parts cost is anywhere from $75 to $105 while the labor cost is anywhere from $35 to $95.
What does a throttle position sensor do?
A throttle position sensor is used to measure how open the throttle valve is and therefore controls the amount of air which can flow into the engines intake manifold.
What is the code for throttle position sensor?
The most common throttle position sensor code is the P0122 – Throttle Position Sensor/Switch A Circuit Low Input. It's triggered when the ECU detects that the TPS circuit A is outputting a lower voltage than expected.
What are the two sensors on a throttle body?
Among the two most important parts within the throttle body are the throttle body position sensor (TPS) and the throttle body temperature sensor.
How do you fix a throttle position sensor?
1:373:09How to Stop Car Hesitation (Throttle Position Sensor) - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo here's another trick get one of these tiny vise grip pliers and grab them to break them loose youMoreSo here's another trick get one of these tiny vise grip pliers and grab them to break them loose you lock the players on super tight. And then pull down on screws then the sensor comes right out.
What is throttle position sensor?
The throttle position sensor is one of the most crucial components of any fuel injection system, right after the computer and fuel injectors in terms of importance. GM Sensors have traditionally been outsourced to overseas manufacturers, the same ones who supply throttle position sensors to other makes like Ford and Toyota.
How to tell if TPS is failing?
The first and most telling symptom of a failing TPS is an idle that rises and falls sporadically or maintains a very high or low RPM. This condition can be extreme enough to cause stalling or to cause the tires to chirp when the transmission is engaged.
Can a TPS cause a stalling engine?
Engine Stalling. As mentioned, a failing TPS can result in random engine stalling at idle, but this can also happen under driving conditions. Most often this will occur under hard braking, since the computer assumes normal operation and continues to deliver cruise-amounts of fuel when the throttle butterfly is shut.
What is a bad throttle position sensor?
A bad throttle position sensor is the last thing that you will ever wish to have on your ride. The purpose of a throttle position sensor is to keep your car running like it’s supposed to by controlling the throttle.
How much does it cost to replace a throttle position sensor?
The labor costs will be anywhere between $60 and $90, depending on the hourly rate of the mechanics. So in total, you can expect to pay between $135 and $220 for a throttle position sensor replacement. Since replacing the TPS is fairly easy in most cases (depending on its location), you may be able to save yourself some time by doing it yourself.
Why does my computer stall my car?
The simple answer is when your computer can no longer detect any signal from the throttle position sensor. The will likely force your computer to stall the engine and only allow it to run at low RPMs, which means the car will only move at slow speeds.
Why does my check engine light turn off?
The check engine light will randomly turn on and off even if the car is running smoothly without any jerks and stalling. This is often the first ever symptom of a bad TPS.
What is the most common symptom of a bad TPS?
Jerking or bucking of the vehicle is the most common symptom of a bad TPS. These jerks can be experienced during hard acceleration or when under moderate load. What makes diagnosing it tricky is that the bucks and jerks may be completely random and not even occur for some stretches of time.
Can you detect throttle position sensor issues?
Honestly speaking, it is not easy to detect throttle position sensor issues. However, there are specific throttle position sensor signs to look for to help ensure you find the culprit.
Can a throttle position sensor cause a car to accelerate?
A faulty throttle position sensor will not let your car accelerate normally. Though this doesn’t happen all the time. You may experience slow acceleration, acceleration surge at both high and low speeds, hesitation or delay in acceleration, and other related symptoms.
Why is my throttle position sensor not working?
Code errors can cause your throttle position sensor to work erratically or incorrectly. Otherwise, you’ll need professional software to reprogram your sensor. This job is best done by a professional mechanic. If your sensor just needs repairs, it could be the result of faulty or loose wiring.
What is the function of the throttle position sensor?
When you press down on the gas pedal, your throttle body unit's valve opens. This causes your throttle position sensor to adjust the engine intake manifold accordingly .
How to install a new sensor?
Install your new sensor by working backward through the removal steps. Start by installing the sensor using the mounting screws. Next, connect your sensor to your vehicle's electrical system using a convenient electrical connector. You should be able to easily push it together and hear a distinct click. Check to ensure a firm connection.
Why does my engine keep idling?
Similarly, if your engine struggles to idle efficiently, it could also be a result of a damaged throttle position sensor. Stalling, surging, or hesitating while idling all can be caused by this unassuming sensor.
Where should the throttle sensor be mounted?
It should be mounted to your throttle body, which is on top of your engine. You should disconnect your negative battery cable before removing the sensor. This helps you avoid the risk of electrical shock or causing an error code on your engine control module.
Can you replace a sensor?
Completely replacing your sensor may be the best way to avoid future issues, but some issues can be easily fixed by reprogramming or repairing your sensor. Reprogramming or resetting your sensor can sometimes solve these issues. This step can also be necessary when you install a new sensor.
Is throttle position sensor a corrosion sensor?
Just like any other electrical wiring, your throttle position sensor is susceptible to corrosion and faulty connections. Once you’ve established the issue is with your sensor and that it isn’t a programming fault, check the wiring and connection points before purchasing a new one.
How to tell if throttle position sensor is bad?
Here are some common symptoms of a bad or failing throttle position sensor to watch for: 1. Car won’t accelerate, lacks power when accelerating, or accelerates itself. It may feel as though the car simply doesn't accelerate as it should, and jerks or hesitates as it picks up speed. It may accelerate smoothly, but lack power.
What is a TPS sensor?
The throttle position sensor (TPS) is part of your vehicle's fuel management system and helps ensure that the correct mixture of air and fuel is delivered to your engine . The TPS provides the most direct signal to the fuel injection system of what power demands are being made by the engine. The TPS signal is continually measured ...
What does it mean when a car accelerates while driving?
When the car accelerates while driving, it usually means the butterfly valve inside the throttle has closed up and pops open suddenly when the driver presses on the accelerator.
Why is the check engine light illuminated?
This sensor can fail gradually, or all at once. In most cases, the Check Engine Light is illuminated if a TPS failure is detected. Also, most manufacturers provide a “limp home” mode of operation with reduced power if a failure is detected.
Why does my car stall when stopped?
This gives the car an unintended burst of speed that occurs because the sensor cannot detect the closed position of the throttle. 2. Engine won’t idle smoothly, idles too slowly, or stalls. If you start to experience engine misfires, stalling, or rough idling when the car is stopped, it can also be a warning sign of a failing TPS.
What happens if your car doesn't accelerate?
1. Car won’t accelerate, lacks power when accelerating, or accelerates itself. 2. Engine won’t idle smoothly, idles too slowly, or stalls. 3. Car accelerates, but won’t exceed a relatively low speed, or shift up. 4. Check Engine Light comes on, accompanied by any of the above behaviors. Next Step.
What does failure mode mean on a TPS?
This is another failure mode of the TPS, which indicates that it is falsely limiting the power being requested with your accelerator pedal foot. You may find that your car will accelerate, but not beyond a speed of 20 - 30 MPH.
What Is A Throttle Position Sensor?
To help understand what a TPS is, we first need to briefly discuss how your engine operates. When you press the gas pedal, the valve on the throttle body opens wider. This allows more air into the engine, and the car’s computer knows that it should spray more fuel into the combustion chamber. In older cars, this was a mechanical process.
Symptoms Of A Bad Throttle Position Sensor
So, how do you know when you have a failing throttle position sensor? Here are some of the most common symptoms of a bad sensor.
How To Fix A Bad Throttle Position Sensor
Most of the time, a bad sensor cannot be fixed. You will need to replace the TPS with a new sensor. You will, however, need to diagnose the problem before replacing the sensor. You want to make sure that the TPS is the root cause of your issue so that you don’t replace it for no reason.
Cost To Replace A Faulty Throttle Position Sensor
Replacing a faulty sensor is not overly expensive. If you visit a repair shop, then you can get the sensor replaced on most vehicles for around $300. Some vehicles have a sensor that is difficult to access, and this will add some expense to the labor cost. It will usually take about an hour to replace the sensor in most cases.
The Bottom Line
Your throttle position sensor is a critical component of your car’s fuel management system. Faulty TPS sensors can cause your vehicle to have odd symptoms that might even become dangerous. You might find that the vehicle does not properly accelerate when you press the pedal, or it could start bucking and surging as you drive.
What happens when your throttle position sensor is bad?
There are many things that may happen when your throttle position sensor is bad. These can range from your car stalling to your transmission not shifting properly. Though this sensor is small, it can lead to many annoying and dangerous problems. When it is not working correctly, the amount of air entering your intake will not be properly regulated.
How do you test a throttle position sensor?
Testing a throttle position sensor requires either an ohmmeter or a voltmeter. If you have a multimeter, then this works too since that includes both tools. You need to test the resistance across the sensor with the accelerator pedal in different positions. Verify the readings against the specs in a repair manual.
How many volts does a throttle position sensor get?
So, in a nutshell when you crank and start your GM car or truck or SUV: 1. The throttle position sensor gets 5 Volts from the Gray wire and Ground from the Black wire. Both of these are provided internally from the PCM. 2.
What happens when you step on the accelerator pedal?
When you step on the accelerator pedal to get the car or truck moving, the throttle opens causing the TP sensor to increase its voltage signal. This is how the PCM knows that the throttle just opened up and that it needs to start injecting more fuel and advancing ignition timing, transmission shift points, etc.
What is a TPS sensor?
Like the majority of throttle position sensors on modern fuel injected cars and trucks nowadays, the GM TPS is a three wire sensor. Each wire provides a specific type of signal to the TPS or to the PCM (Powertrain Control Module=Fuel Injection Computer). Below are the circuit descriptions of each:
How many volts does a TPS send?
2. Once the car or truck starts and is idling and since the throttle is closed, the TPS sends a base throttle position signal of about 0.5 to 0.9 Volts to the PCM on the Blue wire (this voltage will vary slightly on your vehicle but should be within the 0.5 to 0.9 Volts DC). 3.
GMC Sierra: P2138 Symptoms
Here are the most common symptoms associated with P2138. They include:
Bottom Line
P2138 can be a tricky code to diagnose, and it’s an important one to get right. It’s not safe to drive around with a computer-controlled throttle that isn’t sure how much throttle it’s giving your vehicle. Good luck fixing your Sierra!