If the engine of a car is having trouble, it is difficult to find the exact culprit. There are many different components of an engine that could cause an issue as they all work together to provide a nice and smooth acceleration to the vehicle. A car throttle is one such component that could have a serious impact on the health of the engine if it is not working properly.
A throttle position sensor or simply TPS is used for monitoring the position of the throttle valve in an internal combustion engine or in simple words, it is used to monitor the air intake of an engine. It is important to know how to program a throttle position sensor to make the vehicle run efficiently with full capacity.
- How to Program a Throttle Position Sensor
- How to Calibrate the Throttle Position Sensor?
- Does a Throttle Position Sensor Need to be Programmed?
- Basics of Throttle Position Sensor Replacement
- How to Reset the Throttle Position Sensor?
- What if the Above Methods Don’t Work?
- How Does the Throttle Position Sensor Work?
- Safety Precautions
- Is it a Failure?
How to program a throttle position sensor (step by step)
A throttle position sensor is one of the most important sensors in the engine as it maintains the proper amount of air. Technically, you can still drive your car with a bad TPS or throttle position sensor, but the car would not accelerate properly. Inability to shift up and poor acceleration is also some of the most common signs that tell you a defect in your car throttle. Problems in the automatic transmission shifting is another common sign of a bad TPS.
So to fix a bad throttle position sensor, proper steps need to be followed to monitor the accelerator pedal position sensor output signal.
Below is a step-by-step guide involved in programming a throttle position sensor. Let’s have a look at them.
- The first and the most important step is to fully release the accelerator pedal.
- The next step is to turn ON the ignition without putting force on the engine and keep holding the keys.
- Just wait for a few seconds and turn OFF the ignition. Now wait another few seconds and then move on to the next step.
- Again turn ON the ignition, wait a few seconds and finally turn it OFF.
The above steps need to be followed for the acceleration pedal release position.
Follow the below steps for throttle valve closed position learning to monitor the signal of the throttle position sensor output.
- Start and warm up the engine by raising the engine coolant temperature.
- Turn OFF the ignition and wait for a few seconds.
- While on Step 2, make sure to listen to the throttle sound.
How to calibrate the throttle position sensor?
Calibrating the throttle position sensor is an important process after programming it. The accelerator pedal and the Electronic Control Module or the ECM should be calibrated when an initial installment or replacement is done for the accelerator pedal.
Prerequisites for calibrating the throttle position sensor:
- Make sure the car is running so that it can heat up. The battery voltage should be greater than 12.9 volts in an idle state and the engine coolant temperature should be between 77-98 degrees Celsius.
- PNP switch should be turned ON.
- Make sure the headlights and AC are turned OFF to remove any electrical loads on the vehicle being calibrated.
- The steering wheel should be kept in a straight-ahead position, i.e. parking position. This step needs to be done while the operating temperature of the car is going high.
- The cooling fan motor should be turned OFF.
- The car speed should be zero.
- Warm up the gearbox.
When idling, it should be 0 degrees or several degrees. Slowly depress the accelerator pedal until the accelerator is fully open. You can see that the throttle opening gradually increases to 100% at full throttle.
Once ensuring the above preconditions are fulfilled, turn off the ignition and wait for a few seconds.
Steps to calibrate the throttle position sensor:
- Turn the ignition ON and wait for a few seconds.
- Turn the ignition OFF and wait for a few seconds.
- Turn ON the engine and make sure it is warming up at a normal operating temperature.
- Check all the prerequisites mentioned above and make sure they are in place.
- Wait for a few seconds after turning the ignition OFF.
- Now start the engine and keep it in the same state for at least 30-35 seconds.
- The next step is to disconnect the throttle position sensor harness and reconnect it again in a few seconds.
- Now, wait for a few more seconds.
- The next step is to make sure that the idle speed is within specifications to have a complete output.
- The engine needs to be REV two to three times.
- Make sure that the speed is in an idle state and the ignition timing should be within the specified limits.
💡 It is good to use a clock to make sure the timing is accurate to get a proper result at the end.
Does a throttle position sensor need to be programmed?
The throttle position sensor can cause a lot of code errors if not programmed correctly. Below are some of the signs of a bad throttle position sensor.
- Unstable engine at idle state – Irregular idle conditions can be caused by a bad throttle position sensor. The fluctuating airflow inside the engine is the main reason for this.
- Warning lights – Whenever a sensor has a problem, the warning lights are turned ON. A faulty TPS can set a fault code on the computer if it has no voltage reading, sporadic, slow, or constant. This may also cause the engine check light to come on.
- Speed issues – A lot of power issues can be caused by the bad throttle position.
Programming a throttle position sensor can sometimes get tricky and complicated if not done properly. This could be an expensive job depending on the type and model of the vehicle. This job becomes easy if the throttle is positioned in a visibly accessible area and it mostly cost under $600, including the parts and the labor.
Some vehicles get complicated because of the hidden position of the sensor which further requires a lot of disassembling. The cost also gets doubled with more work and complications.
Basics of Throttle Position Sensor Replacement
How to reset the throttle position sensor?
If the cause of the problem in the car is the throttle position sensor, then resetting it is the best option. The simplest step to reset the throttle position sensor is to remove the negative wire from the battery. For a more detailed process, follow the below steps to reset the throttle position sensor.
First throttle sequence
It is important to warm up the engine before completing the below steps. The vehicle needs to be left idle and at the same time, some gas needs to be added to prevent any complications. The below steps work fine when the battery needs to be jump-start on its own and therefore no tools or any machines are required to perform the below steps.
- First step is to turn ON the ignition
- Wait a few seconds and turn the ignition OFF.
- Repeat step 2.
- The next step is to crank the engine.
- Now, the parking brake needs to be pulled.
- The gear level needs to be set to drive.
- Now wait for 5-10 minutes.
Second throttle sequence
Similar to the first throttle sequence, this also does not require any machines or tools. This also does not require the engine to be warmed up. Follow the below steps.
- The first step is to turn ON the ignition without cranking the engine.
- The next step is to press the gas pedal slowly.
- Now wait for a few seconds
- The next step is to release the gas pedal slowly
- Repeat steps 2 to 4 three times
- Now turn OFF the ignition
- Now wait for a few seconds
Removing the battery
In this method, just locate the battery and try to remove or disconnect it. A wrench might be needed to remove the wires from the battery. After disconnecting the battery, keep it aside for a few minutes.
Now without overtightening and breaking the clamps, reattach the wires. The electronic system of the battery gets enough time to discharge completely and restart.
This rarely happens, but it may be sufficient to remove and reinsert the fuse to resolve the throttle position sensor issue. The position of the fuse box varies depending on the car model, so an instruction manual is required.
When the manual is accessible, refer to it again to find a suitable fuse. Once the fuse is located, just use a fuse puller to remove it and make sure it is in good condition. Later, reinsert it again.
Remove the fixing screw
Once cut, you will be able to remove the screw that secures the sensor. Keep them in mind in case you need to reuse them to install new ones.
What if the above methods don’t work?
Model-specific processes and various throttle valve sensors may not solve the problem in any way. At this point, I recommend meeting a mechanic for a diagnostic test.
It is still possible that the sensor will be reset, but if it is not reset, you will need to obtain a replacement to ensure the safe operation of the engine.
How does the throttle position sensor work?
One of the most important parts of the fuel management system is the Throttle Valve Sensor (TPS for short) that connects the accelerator pedal directly to the engine. When the driver steps on the accelerator pedal, the TPS converts this information into valve movement to determine the amount of air entering the engine intake manifold. Increased complexity improves performance and consumes less fuel, but repairs in the event of a failure have proved to be a difficult task and are usually completely replaced.
Just because it looks like an easy task does not mean that you sacrifice safety. Be sure to remove the battery before starting work. It’s not fun to understand that you’re dealing with hot wires in a difficult way. Wear safety glasses and gloves and take good care of your hands and eyes here.
When working under the hood, park your car on flat ground. It is good to move to a quiet place if you do not have a safe parking space. Cleaning the throttle body itself can remove light mud with carburetor fluid and a clean cloth. Do not clean the throttle position sensor during this process as it may be contaminated or damaged cables.
Is it a failure?
Before any symptoms arrive, the first warning signs can be seen with an engine light. Irregular idling speed and engine stall may be due to a defective throttle position sensor. Turn on the ignition and monitor the tachometer. If the car doesn’t have a tachometer, listen to the engine.
Problematic idling can be recognized by the fluctuating speed display and audible changes in engine operation. Poor fuel economy is a powerful indicator that something is wrong. A fully functional engine uses the optimum amount of fuel in all situations, but because the TPS is not functioning properly, the engine is flooded with fuel, reducing power and increasing fuel consumption.
If the accelerator pedal is unresponsive, it can be a more serious problem. As soon as the slow acceleration turns into a series of bumps and dips, the throttle position sensor does not properly convert the pedal input to valve control.
If the valve gets stuck when you open it, nothing happens when you release the accelerator, which is extremely dangerous. If that happens, you can slow down the vehicle by braking, pumping gas to get the throttle sensor response, and shifting to neutral.
It is always worth trying the above methods before going to a mechanic as resetting the throttle position sensor is an easy procedure. The idle problem should be easily resolved but if the gas is unresponsive and performance is inconsistent the throttle position sensor should be replaced.
Older vehicles’ TPS may be physically different or in strange locations, so it’s a good idea to check your vehicle’s service manual for clues.
If you have any further questions regarding the throttle position sensor, please add the comments below.