{"id":506262,"date":"2021-01-13T10:45:35","date_gmt":"2021-01-13T17:45:35","guid":{"rendered":"http:\/\/cartreatments.com\/?p=506262"},"modified":"2021-11-29T13:17:38","modified_gmt":"2021-11-29T20:17:38","slug":"electronic-throttle-control-light","status":"publish","type":"post","link":"https:\/\/cartreatments.com\/electronic-throttle-control-light\/","title":{"rendered":"Electronic Throttle Control Light On? (Here&#8217;s What it Means)"},"content":{"rendered":"<p>During the development of the automobile, several different methods to control engine speed were utilized. Hand throttles were initially popular, but this method faded over time.<\/p>\n<p>Eventually the engine speed and car speed control became the work of the driver\u2019s right foot. Thus the accelerator pedal (or gas pedal) emerged. It was connected to the engine carburetor by a simple linkage or cable.<\/p>\n<p>Pressing this pedal opened the air flow butterfly valve inside the carburetor causing engine speed to increase. This control system proved to be remarkably reliable and persisted pretty much unchanged through the late 1980s.<\/p>\n<p>In the modern automobile (model year 1990 or newer) your right foot does the same job but engine speed is modulated by a completely computerized system. This system is called electronic throttle control (ETC).<\/p>\n<p>This article will discuss this system including the throttle control warning light (TCL) that can alert you to fuel control problems before these problems bring your pleasant ride to a halt.<\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_39 counter-hierarchy ez-toc-counter ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" area-label=\"ez-toc-toggle-icon-1\"><label for=\"item-639b0600a77cd\" aria-label=\"Table of Content\"><span style=\"display: flex;align-items: center;width: 35px;height: 30px;justify-content: center;direction:ltr;\"><svg style=\"fill: #23627c;color:#23627c\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #23627c;color:#23627c\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/label><input type=\"checkbox\" id=\"item-639b0600a77cd\"><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 eztoc-visibility-hide-by-default' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/cartreatments.com\/electronic-throttle-control-light\/#What-is-Electronic-Throttle-Control\" title=\"What is Electronic Throttle Control?\">What is Electronic Throttle Control?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/cartreatments.com\/electronic-throttle-control-light\/#What-is-a-Throttle-Control-Warning-Light\" title=\"What is a Throttle Control Warning Light?\">What is a Throttle Control Warning Light?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/cartreatments.com\/electronic-throttle-control-light\/#What-Does-the-Electronic-Throttle-Control-Light-Look-Like\" title=\"What Does the Electronic Throttle Control Light Look Like?\">What Does the Electronic Throttle Control Light Look Like?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/cartreatments.com\/electronic-throttle-control-light\/#What-Will-Cause-the-TCL-to-Illuminate\" title=\"What Will Cause the TCL to Illuminate?\">What Will Cause the TCL to Illuminate?<\/a><ul class='ez-toc-list-level-3'><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/cartreatments.com\/electronic-throttle-control-light\/#1-ETC-System-Electrical-Problems\" title=\"#1 \u2013 ETC System Electrical Problems\">#1 \u2013 ETC System Electrical Problems<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/cartreatments.com\/electronic-throttle-control-light\/#2-ACV-Butterfly-Valve-Motion-Inhibited\" title=\"#2 \u2013 ACV Butterfly Valve Motion Inhibited\">#2 \u2013 ACV Butterfly Valve Motion Inhibited<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/cartreatments.com\/electronic-throttle-control-light\/#3-Sensor-Malfunction\" title=\"#3 \u2013 Sensor Malfunction\">#3 \u2013 Sensor Malfunction<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/cartreatments.com\/electronic-throttle-control-light\/#Symptoms-of-an-Electronic-Throttle-Control-Problem\" title=\"Symptoms of an Electronic Throttle Control Problem\">Symptoms of an Electronic Throttle Control Problem<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/cartreatments.com\/electronic-throttle-control-light\/#Can-You-Drive-With-the-TCL-Illuminated\" title=\"Can You Drive With the TCL Illuminated?\">Can You Drive With the TCL Illuminated?<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"What-is-Electronic-Throttle-Control\"><\/span>What is Electronic Throttle Control?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-506267\" src=\"http:\/\/cartreatments.com\/wp-content\/uploads\/electronic-throttle-control-valve.jpg\" alt=\"electronic throttle control valve\" width=\"720\" height=\"405\" srcset=\"https:\/\/cartreatments.com\/wp-content\/uploads\/electronic-throttle-control-valve.jpg 720w, https:\/\/cartreatments.com\/wp-content\/uploads\/electronic-throttle-control-valve-200x112.jpg 200w, https:\/\/cartreatments.com\/wp-content\/uploads\/electronic-throttle-control-valve-100x56.jpg 100w\" sizes=\"(max-width: 720px) 100vw, 720px\" \/><\/p>\n<p>Electronic throttle control is a system integrated with your car\u2019s master computer, the <a href=\"http:\/\/cartreatments.com\/pcm-vs-ecm-ecu-tcm\/\">engine control unit<\/a> (ECU). It utilizes a control module operated by the accelerator pedal and an electronic throttle body (<a href=\"http:\/\/cartreatments.com\/bad-idle-air-control-valve-replacement-cost\/\">air control valve<\/a> &#8211; ACV) on the engine.<\/p>\n<p>The electronic fuel injection (EFI) system is also controlled by the ETC. All three devices and systems work together enabling precise engine speed modulation.<\/p>\n<p>When you press the gas pedal down, the ETC system opens the ACV\u2019s internal butterfly valve to admit greater airflow to the engine while the EFI increases fuel flow. Thus the engine speeds up.<\/p>\n<p>At the same time, the ECU adjusts the timing of both the engine valves and ignition in accord with programmed profiles that will produce smooth and powerful engine acceleration.<\/p>\n<p>It should also be noted that the ETC dictates engine speed independent of gas pedal position during the warmup period just after you start the engine. Engine idle speed is automatically elevated to provide smooth cold operation as well as minimize unburned fuel from exiting the engine to the catalytic converters. In this fashion, emissions are minimized during cold start conditions.<\/p>\n<p>Most air control valves include a <a href=\"http:\/\/cartreatments.com\/throttle-position-sensor-symptoms\/\">throttle position sensor<\/a> (TPS). The TPS provides a signal back to the ECU confirming that the air valve is responding precisely as it is commanded by the ECU.<\/p>\n<p>In sports or high performance cars, the ETC may be designed to include several operational modes that can be selected by the driver. These modes might look like this:<\/p>\n<ul>\n<li>A so called \u2018normal\u2019 mode will serve most driving situations and offer the best fuel economy.<\/li>\n<li>A \u2018sport\u2019 mode could alter the ETC throttle position profile giving faster throttle response during acceleration.<\/li>\n<li>The next step might be a \u2018track\u2019 mode. This would be intended to further enhance performance.<\/li>\n<\/ul>\n<p>These alternate modes would also include changes to valve and ignition timing profiles. Of course, selecting a performance setting will decrease fuel economy but will not adversely affect emissions. This multi-mode capability can add to the driving enjoyment for most automotive enthusiasts.<\/p>\n<p>As clever as it may be, the ETC can malfunction. This is when the throttle control warning light (TCL) comes into play.<\/p>\n<p><em>Related: <a href=\"https:\/\/cartreatments.com\/bad-throttle-body-symptoms\/\">6 Symptoms of a Dirty Throttle Body<\/a><\/em><\/p>\n<h2><span class=\"ez-toc-section\" id=\"What-is-a-Throttle-Control-Warning-Light\"><\/span>What is a Throttle Control Warning Light?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The throttle control warning light is located in your car\u2019s instrument panel. This light will illuminate when degraded performance of the electronic throttle control is detected.<\/p>\n<p>Like the <a href=\"http:\/\/cartreatments.com\/how-to-reset-check-engine-light\/\">check engine light<\/a> (CEL), <a href=\"https:\/\/cartreatments.com\/traction-control-light-on\/\">traction control light<\/a>, or other warning lights, this light tells you a problem exists that may require corrective action. See your car\u2019s owner\u2019s manual for further information.<\/p>\n<p>When you see the TCL steadily glowing or flashing, the Onboard Diagnostic System (OBD2) will have set one or more trouble codes. Using a <a href=\"http:\/\/cartreatments.com\/best-automotive-scan-tool\/\">diagnostic tool<\/a>, you or your service technician can display these codes and use them to find the fault(s) with your car\u2019s fuel-air supply and related systems.<\/p>\n<p><em>See Also:&nbsp; <a href=\"http:\/\/cartreatments.com\/p0122\/\">Code P0122<\/a>, <a href=\"https:\/\/cartreatments.com\/p2135\/\">Code P2135<\/a>, <a href=\"https:\/\/cartreatments.com\/p2138\/\">Code P2138<\/a><\/em><\/p>\n<h2><span class=\"ez-toc-section\" id=\"What-Does-the-Electronic-Throttle-Control-Light-Look-Like\"><\/span>What Does the Electronic Throttle Control Light Look Like?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-506265\" src=\"http:\/\/cartreatments.com\/wp-content\/uploads\/etc-light-looks-like.png\" alt=\"ETC light looks like\" width=\"720\" height=\"246\" srcset=\"https:\/\/cartreatments.com\/wp-content\/uploads\/etc-light-looks-like.png 720w, https:\/\/cartreatments.com\/wp-content\/uploads\/etc-light-looks-like-100x34.png 100w\" sizes=\"(max-width: 720px) 100vw, 720px\" \/><\/p>\n<p>The TCL icon in your instrument panel looks like this: a short vertical lightning bolt suspended between two curved inward vertical lines. Generally it will be yellow, red, or orange in color.<\/p>\n<p>This light will momentarily illuminate during your car\u2019s engine start procedure to let you know it is operating.<\/p>\n<div class=\"su-note\"  style=\"border-color:#c0c0c0;border-radius:3px;-moz-border-radius:3px;-webkit-border-radius:3px;\"><div class=\"su-note-inner su-u-clearfix su-u-trim\" style=\"background-color:#dadada;border-color:#ffffff;color:#000000;border-radius:3px;-moz-border-radius:3px;-webkit-border-radius:3px;\"><strong>Note:<\/strong>&nbsp; Not every car will have a throttle control warning light. Check your owner\u2019s manual (printed or online) to determine if your car has one.<\/p>\n<p>If it does, the owner\u2019s manual will also show you the location and appearance of this light. Late model Dodge, Chrysler and <a href=\"https:\/\/cartreatments.com\/why-are-jeeps-so-expensive\/\">Jeep<\/a> products include this feature.<\/div><\/div>\n<h2><span class=\"ez-toc-section\" id=\"What-Will-Cause-the-TCL-to-Illuminate\"><\/span>What Will Cause the TCL to Illuminate?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The following malfunctions will turn on the throttle control light:<\/p>\n<h3><span class=\"ez-toc-section\" id=\"1-ETC-System-Electrical-Problems\"><\/span>#1 \u2013 ETC System Electrical Problems<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Loss of or intermittent signal to or from the ECU or gas pedal module. i. Possible causes:<\/p>\n<p>Faulty wiring or loose\/corroded connectors<\/p>\n<p>Faulty pedal module<\/p>\n<p>Mechanical failure of module linkage to gas pedal<\/p>\n<h3><span class=\"ez-toc-section\" id=\"2-ACV-Butterfly-Valve-Motion-Inhibited\"><\/span>#2 \u2013 ACV Butterfly Valve Motion Inhibited<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Valve unable to move smoothly from idle position to wide open position i. Possible causes<\/p>\n<p>Dirt or corrosion around butterfly valve and\/or shaft<\/p>\n<p>Butterfly valve mechanical failure<\/p>\n<p>Water entry to ACV causing internal corrosion or servo failure<\/p>\n<h3><span class=\"ez-toc-section\" id=\"3-Sensor-Malfunction\"><\/span>#3 \u2013 Sensor Malfunction<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Some type of fault or malfunction in a sensor such as the throttle position sensor (located on the air control valve) can cause the electronic throttle control light to come on.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Symptoms-of-an-Electronic-Throttle-Control-Problem\"><\/span>Symptoms of an Electronic Throttle Control Problem<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-504095\" src=\"http:\/\/cartreatments.com\/wp-content\/uploads\/2019\/10\/gas-pedal-to-floor.jpg\" alt=\"acceleration hesitation\" width=\"720\" height=\"405\" srcset=\"https:\/\/cartreatments.com\/wp-content\/uploads\/2019\/10\/gas-pedal-to-floor.jpg 720w, https:\/\/cartreatments.com\/wp-content\/uploads\/2019\/10\/gas-pedal-to-floor-100x56.jpg 100w, https:\/\/cartreatments.com\/wp-content\/uploads\/2019\/10\/gas-pedal-to-floor-200x112.jpg 200w\" sizes=\"(max-width: 720px) 100vw, 720px\" \/><\/p>\n<p>Engine operation can be adversely affected by any of the above malfunctions. Adverse operation may include any of the following disconcerting behaviors:<\/p>\n<ul>\n<li>Engine stalling<\/li>\n<li>Engine misfiring<\/li>\n<li>Rough or lumpy idling<\/li>\n<li><a href=\"http:\/\/cartreatments.com\/car-jerks-when-accelerating\/\">Inability to smoothly accelerate<\/a><\/li>\n<li>Inability to maintain a constant speed<\/li>\n<li>Reduced cruising speed\n<ul>\n<li>The car will reach a certain speed but go no faster.<\/li>\n<li>This may occur if the ECU determines higher speeds will damage the engine or related systems. This is referred to as <a href=\"http:\/\/cartreatments.com\/limp-mode\/\">limp mode<\/a>.<\/li>\n<\/ul>\n<\/li>\n<li>Engine will either <a href=\"http:\/\/cartreatments.com\/engine-cranks-but-wont-start\/\">not start<\/a> or be difficult to start<\/li>\n<li>Noticeable <a href=\"http:\/\/cartreatments.com\/bad-gas-mileage\/\">reduction in fuel economy<\/a><\/li>\n<li>Black smoky exhaust<\/li>\n<\/ul>\n<p>As mentioned above, any problems that cause the TCL to come on will set a fault code. The check engine light (CEL) will also illuminate.<\/p>\n<p>ETC problems can mimic other engine system issues. This is where OBD2 fault codes can prove to be exceptionally beneficial in enabling proper diagnostic work.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Can-You-Drive-With-the-TCL-Illuminated\"><\/span>Can You Drive With the TCL Illuminated?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A <strong>steadily lit throttle control light<\/strong> indicates an intermittent or ongoing problem, but the car may still be driven. It is possible that the ECU will limit top speed as discussed above. The TCL \u2018on\u2019 condition should be addressed as soon as possible to avoid cumulative damage to other systems in your car.<\/p>\n<p>A <strong>flashing throttle control light<\/strong> (like a flashing CEL) indicates a serious problem that will require immediate service. Beyond reaching a safe place off the side of the road, the car should not be further driven when either of these warnings are noted.<\/p>\n<div class=\"su-note\"  style=\"border-color:#c0c0c0;border-radius:3px;-moz-border-radius:3px;-webkit-border-radius:3px;\"><div class=\"su-note-inner su-u-clearfix su-u-trim\" style=\"background-color:#dadada;border-color:#ffffff;color:#000000;border-radius:3px;-moz-border-radius:3px;-webkit-border-radius:3px;\"><strong>Note:&nbsp;<\/strong> Some ETC failures will result in degraded regulation of the <a href=\"http:\/\/cartreatments.com\/air-fuel-ratio-at-various-conditions\/\">fuel-air ratio<\/a>. If excessive fuel flows into the engine during such a failure, incomplete combustion is probable.<\/p>\n<p>This will admit excess unburned fuel to the catalytic converter(s) in the exhaust system causing localized extreme temperatures.<\/p>\n<p>Overheating of the converter(s) may result in damaging or internally destroying these costly devices. This is just one key reason why expeditiously heeding the warning posed by the illuminated TCL and\/or CEL is always wise.<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"<p>During the development of the automobile, several different methods to control engine speed were utilized. Hand throttles were initially popular, but this method faded over time. Eventually the engine speed and car speed control became the work of the driver\u2019s &#8230; <a title=\"Electronic Throttle Control Light On? (Here&#8217;s What it Means)\" class=\"read-more\" href=\"https:\/\/cartreatments.com\/electronic-throttle-control-light\/\" aria-label=\"More on Electronic Throttle Control Light On? (Here&#8217;s What it Means)\">Read more<\/a><\/p>\n","protected":false},"author":1007,"featured_media":506264,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_lmt_disableupdate":"no","_lmt_disable":"no"},"categories":[35,58],"tags":[100551,100552,100340],"modified_by":"Mark Stevens","_links":{"self":[{"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/posts\/506262"}],"collection":[{"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/users\/1007"}],"replies":[{"embeddable":true,"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/comments?post=506262"}],"version-history":[{"count":0,"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/posts\/506262\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/media\/506264"}],"wp:attachment":[{"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/media?parent=506262"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/categories?post=506262"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/tags?post=506262"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}