- [Robot kits](https://robotsforthat.com/robot-kits/) / **ELEGOO Smart Robot Car V4 troubleshooting** Updated 2026-10-27 # ELEGOO Smart Robot Car V4 troubleshooting Researched by [Riley Hart](https://robotsforthat.com/author/riley-hart/) · based on ELEGOO Smart Robot Car V4 build guide and docs · we may earn a commission Most problems come from 3 places: a motor plug in the wrong port, the upload and cam switch on the wrong side, or a cable that is not fully in. Find your problem below and try the fixes in order. **ELEGOO Smart Robot Car Kit V4.0** About $66 to $80. Every part and tool in one box. [Check price on Amazon](https://www.amazon.com/dp/B07KPZ8RSZ?tag=robotsforthat-20) ## Find your problem - The app will not connect - No camera picture - The car spins in circles or drives backward - The remote does nothing - It misses the line - Nothing turns on - A wheel wobbles or falls off - The eyes point sideways ## The app will not connect **Why it happens:** The board switch is on upload, or the phone left the car's Wi-Fi. - Slide the small switch on the expansion board to cam. - Join the ELEGOO Wi-Fi again and stay connected when it says No internet. - In the app, tap the link icon in the top right. Comes from [step 26: Switch to camera mode](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-build-guide/#step-26). [See the full fix with the drawing](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-app-wont-connect/). ## No camera picture **Why it happens:** The camera cable is loose or the camera board is upside down. - Check the 4 wire camera cable is clicked in at both ends. - Check the lens sits at the top of the bracket. - Switch off, switch on and reconnect. Comes from [step 16: Plug in the eyes and the camera](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-build-guide/#step-16). [See the full fix with the drawing](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-no-video/). ## The car spins in circles or drives backward **Why it happens:** Motor plugs are in the wrong ports. - Left front M1, right front M2, right rear M3, left rear M4. - Front is the end with the eyes. Comes from [step 18: Plug in the four motors](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-build-guide/#step-18). [See the full fix with the drawing](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-spins/). ## The remote does nothing **Why it happens:** The plastic tab is still in the remote, or the battery is low. - Pull the clear plastic tab out of the remote. - Point it at the car from close up. - Charge the car if the status light is red. Comes from [step 24: Drive with the remote](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-build-guide/#step-24). [See the full fix with the drawing](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-remote/). ## It misses the line **Why it happens:** The line sensor needs contrast and the right threshold. - Use black tape on a light floor. - Press 4 or 6 on the remote to tune the sensor, 5 to reset. - Check the 5 wire cable is in at both ends. Comes from [step 29: Let it drive itself](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-build-guide/#step-29). [See the full fix with the drawing](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-line/). ## Nothing turns on **Why it happens:** The battery is flat or switched off. - Slide the battery box switch to ON. - Charge it with USB for about 2 hours. The light is green while charging. Comes from [step 23: Switch it on](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-build-guide/#step-23). [See the full fix with the drawing](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-no-power/). ## A wheel wobbles or falls off **Why it happens:** The wheel went on at an angle or the screw is missing. - Pull the wheel off and line up the flat side of the shaft. - Fix it with the M2x25 screw through the center. Comes from [step 21: Put on the four wheels](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-build-guide/#step-21). [See the full fix with the drawing](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-wheel-wobble/). ## The eyes point sideways **Why it happens:** The servo plug is backwards or the servo arm was turned by hand. - Check the servo plug is in Servo1 with brown on GND. - Switch off and on so the servo centers itself. Comes from [step 15: Plug in the servo](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-build-guide/#step-15). [See the full fix with the drawing](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-servo/). Still stuck? ## Show the AI coach a photo Open the step you are on, tap Stuck and take a photo. The coach checks it against that exact step and tells you what to fix. 3 free questions per kit. [Open the build tool →](https://robotsforthat.com/lab/build/elegoo-car-v4/steps/) ## More robot kit guides [How to build the ELEGOO Smart Robot Car V4, step by step Build the ELEGOO Smart Robot Car Kit V4.0 step by step. A drawing for every step, the right screw for each part and the mistakes to avoid.](https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-build-guide/)[Best robot kits Pick the right kit for your age and budget.](https://robotsforthat.com/robot-kits/) ## Sources - [ELEGOO Smart Robot Car V4.0 assembly tutorial (PDF)](https://drive.google.com/drive/folders/1hACczXN-CzxTFHsO3yrLW7QJ1HhHiZJJ) - [ELEGOO Smart Robot Car V4.0 downloads](https://www.elegoo.com/blogs/arduino-projects/elegoo-smart-robot-car-kit-v4-0-tutorial) Drawings by robotsforthat. ELEGOO Smart Robot Car V4 is a trademark of ELEGOO. We are not affiliated with ELEGOO. HTML version: https://robotsforthat.com/robot-kits/elegoo-smart-robot-car-v4-troubleshooting/