RC Car Not Responding to Throttle

RC Car Not Responding to Throttle? Here’s How to Fix It!


You’re ready to zoom around the race track with your RC car. You turn the throttle. But, the car doesn’t move. You don’t have to worry just because the car won’t respond to the throttle.

So, how to fix RC car not responding to Throttle?

You need to correctly set up your RC and calibrate the ESC to make your RC respond to the throttle. Make sure that the batteries are adequately charged before running the RC. Properly align the gears and replace bad motors and throttle servo. Doing so can help you fix the RC throttle problem.

That’s a very brief explanation of what could be wrong and how to fix it. We will be delving into the nitty-gritty of each probable issue.

So without further ado, let’s get started. 

Why Is My RC Car Not Responding to Throttle?

Over the last 8+ of my obsession with RC has thrown me against quite a good number of struggles.

Back when I started toying around with RC cars, dealing with their issues used to be a huge pain up my neck. But now, after almost 10 years of dueling in the niche, I find myself welcoming such instances as challenges. How time changes people!

Okay, we are talking about unresponsive RC throttle today.

It’s actually one of the most forgiving problems that you can easily deal with. Unlike other problems that can take a huge toll on your wallet, you don’t really have to worry about that in this case.

However, this is one of those problems which can stem from a lot of circumstances. So it can get a bit tedious to figure out the root cause of the issue.

With that said, here’s a list of 10 reasons that can lead to the unresponsive throttle problem:

  1. Incorrect RC setup
  2. Transmitter and receiver incompatibility
  3. Failed transmitter/radio
  4. Battery failure
  5. Worn-out throttle servo
  6. Bad Servo Wire
  7. ESC is not calibrated properly
  8. Motor failure
  9. Gears not aligned correctly
  10. Throttles switched off by optidrive

Whenever I face any throttle issues, I follow the above-provided sequence to figure out the root of the problem.

Let me walk you through all the steps one by one:

Incorrect RC Setup

This step is pretty much self-explanatory.

Not every one of us can get it right every single time. Even I mess up my RC setup at times. No shame in admitting it!

The idea here is to double-check your RC setup to see if your missed anything that can lead to this issue. Here are all the things you check to make sure that there’s nothing wrong with your setup:

  • Check if your RC and the transmitter are turned on. Make sure that they have adequate power running through them.
  • After that, test your battery condition to check if it’s capable enough to power your RC.
  • Notice carefully if the neutral point of your receiver has been changed in any way.
  • The throttle trim position should be in its default position.
  • Make sure that the antennas are working properly. Check if there is any metal substance in contact with the antenna.
  • The transmitter should be at the same frequency as the RC car.

Ran your little diagnostic? That should give you an idea of why your RC car is not responding to the throttle.

Let’s move on to the other possible reasons.

Compatibility Issues

Your RC car’s unresponsiveness could be caused by incompatibility. This can happen especially if you’re using an aftermarket transmitter. 

When your car isn’t responding to throttle it’s best to start from this diagnosis. Inspect the list of compatible devices for both devices. If your transmitter isn’t compatible you’ll have to change it. 

The ESC tells your RC where the neutral, full throttle, and maximum breakpoints are. If your ESC is broken or uncalibrated your RC will not function. 

You can read more about it and learn if it’s possible to bind any transmitter to any receiver.

Failed Transmitter

Up next, I prefer to check if my RC transmitter is working properly or not.

How do I know that there is a problem with my RC transmitter?

Switch the steering servo plug with the throttle around the RC car. Now try accelerating the RC without steering. If your RC accelerates without any steering, then you can be sure that something is wrong with your transmitter. Another way to find it out is by using a substitute compatible transmitter. If it works, then your original transmitter is faulty.

If you can activate steering without any throttle control, then your throttle servo has likely gone bad.

In such a scenario, I would suggest you attempt to troubleshoot your transmitter.

Looking to repair your RC transmitter? Here’s a 9-minute-long Youtube video that can help you:

This video covers some great tutorials on how to repair a broken transmitter.

Your RC car will also not respond to the controller if they are not set to the same frequency. Set your RC car and controller to the same frequency to make your RC car respond to the controller.

Battery Failure

Another reason for RC throttle not responding is deteriorating battery life. Your RC will run sluggishly if the battery is not properly charged.

Without the batteries providing enough juice your RC won’t be doing much of anything. So, make sure they are charged and in good condition. 

We got impressive coverage on checking NIMH battery condition. Check that out!

If your battery has been well worn out due to its age and use, just go on and grab a new one! It doesn’t cost much anyways!

Batteries with any signs of physical wear should be immediately replaced. You can also use a multimeter to check the battery if there’s no substantial impairment. 

But I suggest taking proper care of your batteries. Just to be on the safe side.

Here’s how you can take care of your RC battery.

After every use, you should deplete the remaining charge from your battery before storing it at optimal temperature. Overcharging the batteries will simply work on damaging them. So refrain from that!

Source: rcgeeks.co.uk

Worn Out Throttle Servo 

I’ve already mentioned how to check a worn-out throttle servo at the start of this guide. But to save you from inconvenience, I’m going to mention it again anyways.

How to identify a worn-out throttle?

Swap the servo plugs around on the receiver. Now try squeezing your trigger and using the steering too. If the steering responds but the throttle doesn’t, then you have a bad throttle servo. 

This process is a swift and easy way to check for servo damage. But, you should also consider buying a good servo tester.

The best bet is to buy a new servo motor. However, you can try opening it up to replace damaged parts.

First, flip your servo motor and unscrew the four screws. Next, take the top off and examine the gears. If any of the gears are broken or damaged in some way you’re in luck. 

Broken gears can easily be changed. Just check the parts number on your servo. Then order parts for it from your preferred website. The parts will come with detailed instructions along with visuals. 

Follow those instructions to replace the gears and make your servo functional again. However, if the gears aren’t busted then the problem is probably electronic. In that case, you’ll have to substitute the motor.

Bad Servo Wires

This one is the easiest to diagnose. Just trace all the wires from end to end. Tug on the wires lightly to check if they are loose. 

If any wires have come loose, reconnect them. You might also want to re-solder some wires.

Soldering servo wires is very easy. Here’s how to solder servo wires:

Slip some heat-shrink over the wires and strip the ends before twisting the wires together. Add solders to the joints of the wires and slip some more heat-shrink over the joint. Heat the joint using a soldering iron.

That’s pretty much it!

If you don’t have a soldering iron you should consider getting one. It’s a very handy tool for any RC enthusiast!

If you want, you can look for soldering irons that work best with RCs. 

You can also use servo wire crimping tools to work your way around crimping the wires if necessary.

Source: learn.sparkfun.com

ESC Not Calibrated Properly

It can be highly possible that your ESC is not calibrated properly. Or maybe it’s not calibrated at all!

Whichever it is, you need to dip your feet in it right away.

Your RC will think that your throttle is in neutral despite being on the full throttle if your ESC is out of calibration. The RC will keep cutting out if the ESC is not calibrated properly.

First, test the ESC with a multimeter. In case it’s broken, change it. If it’s not broken it might not be calibrated properly. 

So, here’s how to calibrate RC car ESC:

To calibrate your ESC press the switch and wait till the light turns solid. After that, squeeze the trigger on your transmitter for max throttle. Hold it at max throttle till you hear a confirmation beep. Once you hear the confirmation beep, let go of the throttle and go for a max break. Switch to neutral after the confirmation and repeat the process.

When setting up max throttle and break, be quick about it. Don’t pause in between. 

Damaged Motor

Still couldn’t fix the issue? Well, that’s unfortunate.

How about we take a look at the motor?

If everything thus far is in perfect condition, then your motor might be the issue. However, before you stamp it as damaged you should at least have a look at it.

Check if your motor is overheating. That’s a clear indication that your RC is going bad. Similarly, notice if your motor is making noises or vibrating unusually while running. These are all indication of a worn-out motor.

A burned motor will have visible burn marks around it. Oftentimes, exceeding the max RPM range allowed by the motor can damage it.

Another way to check the motor is by checking how freely it moves. Use your finger and notice if there is any resistance while turning the ball bearings of the motor. A good motor won’t have any bumps or any sort of resistance while turning.

You can learn more about identifying bad RC motor from our coverage.

Now that we learnt how to identify a bad rc motor, it’s time to fix the the issue.

Here’s how to fix bad RC motor:

To fix a bad rc motor, start by clean the motor first. A gunked-up motor might not work correctly. Sprinkle some WD40 into the motor and then use compressed air to wash it.

If that doesn’t do it, try opening up the motor. 

Check the ball bearings by turning them manually once you have access. If they are damaged you can replace the ball bearings and try again.

Next, check if the magnets are misaligned or damaged. If they are, you’ll need to secure them in place with glue.

Gears Not Aligned Correctly 

Unaligned pinion gears can be partially responsible for your RC not responding to throttle. And even if your car does respond to the throttle, your RC car won’t go full throttle.Make sure that the pinion gear is aligned properly with the spur gear.

Stripped gears should be replaced with new ones. Tighten the pinion gears and realign it with the spur gear.

You can identify stripped gears by the grinding sound emitted when the car accelerates without moving forward. Loose gears will also result in the same outcome.

Throttles Switched Off By Optidrive

This is the last one, I promise!

Let’s be honest, you have to be very unfortunate to come this far. It’s a very rare issue that’s only triggered if certain conditions are met.

Optidrive has its own failsafe mechanism that can shut down the power supply to the throttle servo if triggered. You can notice the a red light on the Optidrive, indicating that the failsafe has been activated.

Source: ebay.com

So, why does Optidrive trigger the failsafe?

When the Optidrive detects a loss of connection with the transmitter, it goes to failsafe mode and shuts downs the power supply to the throttle servos. Optidrive can also activate failsafe mode if your batteries don’t have enough charge.

Try to understand exactly why your Optidriver failsafe was activated by reading the instruction manual. Turning the failsafe mode off will hopefully fix the issue.

That’s all!


Can I charge a dead LiPo battery?

Answer: Yes, you can, it hasn’t been dead for too long. Attach the battery to a charging pack, and select NiCd. And charge it till it reaches around 10V. After that, switch it back to LiPo and keep charging. Do not charge a dead battery unattended.

How to maintain a LiPo battery properly?

Answer: Keep your battery disconnected from the ESC when the RC is not in use. And don’t charge your LiPo battery with a NiMH charger. 

How can I make my servos last longer? 

Answer: Make sure your servos are calibrated and aren’t extending beyond the limits of your RC. This could overheat the servo and wear it out prematurely.


An RC car not responding to throttle can have a wide range of internal issues. Reading about the issues online could overwhelm you. But, if you go about the diagnostic process in an orderly fashion it’ll seem easier.

Did you enjoy the troubleshooting process? I sure did! But it’s absolutely okay if you don’t have that much time on your hand like me!

If you are okay with spending money after your RC, you can just take it down to your local hobby shop and let them fix it for you. No pressure!

That’s all from me today. Hope your car is now ready for the tracks.

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