# Reading Codes

**URL:** <https://forums.speedlife.net/t/reading-codes/110499>\
**Category:** SON240sx Automotive\
**Created:** [October 24, 2007, 5:46pm UTC](https://forums.speedlife.net/t/reading-codes/110499 "2007-10-24T17:46:52Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Neggy](https://avatars.discourse-cdn.com/v4/letter/n/f475e1/32.png) [@Neggy](https://forums.speedlife.net/u/Neggy)\
**Post date:** [October 24, 2007, 5:46pm UTC](https://forums.speedlife.net/t/reading-codes/110499/1 "2007-10-24T17:46:52Z")

</div>

On ym freinds 240sx his digital speedo and heads up don’t work( problem for another day). how do I check the fault codes if I can’t see the check engine light?

From what I have read the Idle control knob on the back of the comp is used to check the codes. does this also actually control the idle?

So u turn the car to run turn the knob clock wise then conter. the 2 led’s inside the comp will flash the codes?