# Issues with picar-4wd

**URL:** <https://forum.sunfounder.com/t/issues-with-picar-4wd/260>\
**Category:** Robotic kit for Raspberry Pi\
**Created:** [May 4, 2023, 7:21am UTC](https://forum.sunfounder.com/t/issues-with-picar-4wd/260 "2023-05-04T07:21:43Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![wil328](https://avatars.discourse-cdn.com/v4/letter/w/bc79bd/32.png) [@wil328](https://forum.sunfounder.com/u/wil328)\
**Post date:** [May 4, 2023, 7:21am UTC](https://forum.sunfounder.com/t/issues-with-picar-4wd/260/1 "2023-05-04T07:21:43Z")

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Hi,

I am trying to run the ‘picar-4wd test servo’ command during assembly, but I keep getting an error (picture below). It was working fine a few days ago but today when I started it up, it’s not.

I do not have much knowledge of RPi yet, but it seems to me like it’s an I2C problem. So I ran i2cdetect as I saw on forums online and there seems to be a problem too (picture below)

 ![image](https://canada1.discourse-cdn.com/flex029/uploads/sunfounder/original/1X/331cbe7fba387b127c645178549ea96f94337519.png)

Please help! Thank you 🙂

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<div class="post-metadata">

**Author:** ![wil328](https://avatars.discourse-cdn.com/v4/letter/w/bc79bd/32.png) [@wil328](https://forum.sunfounder.com/u/wil328)\
**Post date:** [May 4, 2023, 7:22am UTC](https://forum.sunfounder.com/t/issues-with-picar-4wd/260/2 "2023-05-04T07:22:22Z")

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![image](https://canada1.discourse-cdn.com/flex029/uploads/sunfounder/original/1X/d66b400183a93fc7a27f8fc6eb04017833f30300.png)

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<div class="post-metadata">

**Author:** ![wil328](https://avatars.discourse-cdn.com/v4/letter/w/bc79bd/32.png) [@wil328](https://forum.sunfounder.com/u/wil328)\
**Post date:** [May 4, 2023, 7:23am UTC](https://forum.sunfounder.com/t/issues-with-picar-4wd/260/3 "2023-05-04T07:23:20Z")

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![image](https://canada1.discourse-cdn.com/flex029/uploads/sunfounder/original/1X/11fbd7eb242bd87e3074f3f34e043208b54269f6.png)

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<div class="post-metadata">

**Author:** ![SunFounder\_Moderator](https://avatars.discourse-cdn.com/v4/letter/s/34f0e0/32.png) [@SunFounder\_Moderator](https://forum.sunfounder.com/u/SunFounder_Moderator)\
**Post date:** [May 5, 2023, 8:33am UTC](https://forum.sunfounder.com/t/issues-with-picar-4wd/260/4 "2023-05-05T08:33:24Z")

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1、Please make sure you have connected the battery to power the robot hat, and whether the battery power is sufficient.  
2、Whether the GPIO pins of robot hat and Raspberry Pi are connected firmly.  
3、Execute sudo raspi-config, enter the setting page, and turn on the i2c service. (As shown in the picture)  
 ![524DA15B-4388-434b-B789-28C146101FF6](https://canada1.discourse-cdn.com/flex029/uploads/sunfounder/original/1X/0838c83650108117bd9f9401de1d4e2a8a76a53a.png)  
 ![805729CF-D06A-4665-AA44-9389E6F4D9F1](https://canada1.discourse-cdn.com/flex029/uploads/sunfounder/original/1X/d28f14e5f1541451ed95171d587fded6d25564a4.png)  
 ![3](https://canada1.discourse-cdn.com/flex029/uploads/sunfounder/original/1X/6e7e060d85446a7bd96a779855abd491163d1321.png)  
 ![4](https://canada1.discourse-cdn.com/flex029/uploads/sunfounder/original/1X/2b6c88d24a5b6bce8a90b48b92124de1090ed7a8.png)

4、Execute picar-4wd soft-reset to reset the controller.