Hyundai Won’t Accelerate: Throttle Position Sensor Problem
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Is your Hyundai not accelerating because of a throttle position switch problem? Learn the common problems that can cause Kia and Hyundai vehicles not to accelerate. In one situation, a Kia only accelerated to about 15 mph and would not go any faster.
At a Glance
- Symptom: no power, RPM stuck near 2000, car will not go past about 15 mph
- Why: the engine computer enters limp mode when throttle position signals disagree
- Common codes: P0123, P0222, P2101, P2135
- Usual fix: clean or replace the electronic throttle body or throttle position sensor
- Also check: a clogged catalytic converter if there are no throttle codes
Problem
Kia or Hyundai vehicles may fail to accelerate due to problems with the throttle position switch. When the driver presses the gas pedal, the maximum speed the car can reach is up to 15 mph. Common symptoms include the engine having no power when you press the gas pedal and engine RPMs not going past 2000.
The first warning that you may get is the check engine light will come on. Soon after, you may notice that the engine or vehicle speed does not increase when you press the gas pedal. This issue is common to be intermittent at the early stages.
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It is easy to misdiagnose this problem as an engine misfire. Thus, changing the spark plugs will not solve the problem if a faulty throttle position sensor causes the issues. You may also wonder if the car is out of gas. That’s why it is important to read the CEL.
Why Won’t a Hyundai Accelerate?
Here are the most common problems preventing a Hyundai from accelerating or responding when pressuring the gas pedal.
Throttle Position Body
A faulty throttle position switch, called the TPS, is the most common issue that can make your vehicle not accelerate. The Throttle Position Sensor is a potentiometer that controls the throttle valve. Check with the dealer to see if they have an updated position switch.
Replacing the TPS at the dealership can cost around $400 to $600, depending on your location and model. Replacement TPS for Kia and Hyundai can also be purchased online.
Catalytic Converter
A bad catalytic converter can also cause your Kia / Hyundai not to accelerate.
Typically, you can get to speeds over 50mph when the catalytic converter is defective, but it may take a while for the car to get up to that speed. When the catalytic converter gets clogged, it creates excessive backpressure, and thus the vehicle loses power. You can have a muffler shop perform a backpressure exhaust test on your vehicle.
This will confirm if the catalytic converter is defective or not. Replacing cat converters can be expensive. They can cost nearly $1,000 if you want an OEM catalytic converter, but aftermarket units cost only $200 to $300 at a muffler shop.
How do you diagnose a Hyundai that won’t accelerate?
Several fault codes may be present when the vehicle fails to accelerate. You can use a YOUCANIC Full System OBD2 scanner reader to retrieve the codes from your car.
Here is the list of codes that a defective TPS triggered.
- P0123: Throttle Position Sensor/Switch A Circuit High Input
- P0222: Throttle/Pedal Position Switch/Sensor B Circuit Low Input
- P2101: Throttle Actuator Control Motor Circuit Range/Performance
If you want a more specific scanner that can read and clear fault codes to every control module on supported vehicles, use the YOUCANIC Full System Scanner.
How Do You Replace the Hyundai Throttle Position Sensor?
- Open the hood.
- Disconnect the negative battery terminal.
- Locate the electronic throttle body. The throttle body is mounted on the intake manifold assembly.
- Remove the air intake hose.
- Disconnect the electrical connector from the TPS.
- Remove the four bolts on the TPS using a 10 mm socket.
- Reinstall in reverse order. Tighten the bolts to 11.5 Nm.
Frequently Asked Questions
Why will my Hyundai not go over 15 mph?
The engine computer has entered limp mode, usually because of a throttle position sensor or throttle body fault. Read the codes to confirm before replacing parts.
What does P2135 mean on a Hyundai?
The two throttle position sensor signals disagree. It is commonly caused by a worn electronic throttle body or a wiring problem at its connector.
Do I need to relearn the throttle after replacing it?
Many Hyundai and Kia models relearn on their own after the battery is reconnected and the engine idles for a few minutes. Some need a reset with a scan tool.
Check these troubleshooting and repair guides for more help on your Hyundai.
(No subject)
My car’s (Santafe 2010) won’t revv above 4000rpm
Our 2012 Tuscon does some similar behavior: It would get to 20-30 mph and then the transmission would down shift, rev up, but loose drive power. No codes. Thought it was a clogged air filter, replaced that – no change. Thought it might be a problem with the torque converter, replaced transmission fluid – maybe slight improvement, but now the car mostly bogs down when attempting to accelerate instead of the downshifting with no accompanying increase in power to the wheels that was happening some before. Sometimes I can only get it over 30 going going down hill. If I manually downshift, I can get more RPMs and maybe a little more power, but it will still have a difficult time accelerating much. Maybe fuel starved, but then I wouldn’t imagine that it would rev up to 4-5k RPMs. It did seem to behave slightly better after I filled the gas from 1/5 of a tank to full. At a bit of a loss for good ideas. Is it worh replacing the fuel pump?
Our 2012 Tuscon does some similar behavior: It would get to 20-30 mph and then the transmission would down shift, rev up, but loose drive power. No codes. Thought it was a clogged air filter, replaced that – no change. Thought it might be a problem with the torque converter, replaced transmission fluid – maybe slight improvement, but now the car mostly bogs down when attempting to accelerate instead of the downshifting with no accompanying increase in power to the wheels that was happening some before. Sometimes I can only get it over 30 going going down hill. If I manually downshift, I can get more RPMs and maybe a little more power, but it will still have a difficult time accelerating much. Maybe fuel starved, but then I wouldn’t imagine that it would rev up to 4-5k RPMs. It did seem to behave slightly better after I filled the gas from 1/5 of a tank to full. At a bit of a loss for good ideas. Is it worh replacing the fuel pump?
Ok jennifer i have the solution for u my car i have changed three sensors last week i almost jailed a part shop dealer then i tried something……. I removed the air sensor as they mentioned that u should change it and covered it with aluminium foil paper with only the two bolts holes open and mounted it back to its place and the rev. Came back to normal and i still drive and no complains abt it…… My car is a hyundai getz 2009 model
look at the crank shaft sensor
I’d you get a answer with this problem, mine goes 15 miles than stops and engine sounds accelerated than comes back to coast for 2-5 miles p/h
I have had this happen…. dies down and then seems to jump gears… Tranny is good… I just had new plugs and wires put on.. (140K miles) hit a code PO121 so I replaced the TPS after clearing the code.. Now it does it again..2 times since. but..no check engine light… no code. Now what I do is remove both cables off the battery and hold them together for 5 or 10 min. reattach and it works…for a few days… New plugs/wires and TPS….??????
My car seems to be having this problem & I have taken my car to the Hyundai dealership over 4 times . They have kept it for weeks at a time but claim that they cant find amy problems with my car. My car is dangerous to drive. The dealership claims the problem doesn’t happen when they drive the car but it happens to me EVERY time I’m driving the car !! this is very frustrating and upsetting.