{"id":16220,"date":"2021-07-30T00:25:00","date_gmt":"2021-07-30T07:25:00","guid":{"rendered":"https:\/\/blogv2prod.wpenginepowered.com\/blog\/?p=16220"},"modified":"2024-05-27T21:15:13","modified_gmt":"2024-05-28T04:15:13","slug":"p0641-code-sensor-reference-voltage-a-circuit-open","status":"publish","type":"post","link":"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/","title":{"rendered":"P0641 Code: Sensor Reference Voltage &#8220;A&#8221; Circuit\/Open"},"content":{"rendered":"<!DOCTYPE html PUBLIC \"-\/\/W3C\/\/DTD HTML 4.0 Transitional\/\/EN\" \"http:\/\/www.w3.org\/TR\/REC-html40\/loose.dtd\">\n<html><body><span class=\"span-reading-time rt-reading-time\" style=\"display: block;\"><span class=\"rt-label rt-prefix\">Reading Time: <\/span> <span class=\"rt-time\"> 5<\/span> <span class=\"rt-label rt-postfix\">minutes<\/span><\/span><style>.kadence-column_0f199a-09 > .kt-inside-inner-col{border-top-width:0px;border-right-width:0px;border-bottom-width:0px;border-left-width:0px;}.kadence-column_0f199a-09 > .kt-inside-inner-col,.kadence-column_0f199a-09 > .kt-inside-inner-col:before{border-top-left-radius:0px;border-top-right-radius:0px;border-bottom-right-radius:0px;border-bottom-left-radius:0px;}.kadence-column_0f199a-09 > .kt-inside-inner-col{column-gap:var(--global-kb-gap-sm, 1rem);}.kadence-column_0f199a-09 > .kt-inside-inner-col{flex-direction:column;}.kadence-column_0f199a-09 > .kt-inside-inner-col > .aligncenter{width:100%;}.kadence-column_0f199a-09 > .kt-inside-inner-col:before{opacity:0.3;}.kadence-column_0f199a-09{position:relative;}@media all and (max-width: 1024px){.kadence-column_0f199a-09 > .kt-inside-inner-col{flex-direction:column;justify-content:center;}}@media all and (max-width: 767px){.kadence-column_0f199a-09 > .kt-inside-inner-col{flex-direction:column;justify-content:center;}}<\/style>\n<div class=\"wp-block-kadence-column inner-column-1 kadence-column_0f199a-09 qk-look-widget\"><div class=\"kt-inside-inner-col\">\n<div class=\"wp-block-ultimate-post-row ultp-block-560d09  qk-main-wrap\"><div class=\"ultp-row-wrapper\"><div class=\"ultp-row-content\">\n<div class=\"wp-block-ultimate-post-column ultp-block-86026f\"><div class=\"ultp-column-wrapper\"><style>.wp-block-kadence-advancedheading.kt-adv-heading_654ebe-22, .wp-block-kadence-advancedheading.kt-adv-heading_654ebe-22[data-kb-block=\"kb-adv-heading_654ebe-22\"]{text-align:center;font-size:20px;font-style:normal;}.wp-block-kadence-advancedheading.kt-adv-heading_654ebe-22 mark.kt-highlight, .wp-block-kadence-advancedheading.kt-adv-heading_654ebe-22[data-kb-block=\"kb-adv-heading_654ebe-22\"] mark.kt-highlight{font-family:Inter;font-weight:500;font-style:normal;color:#f76a0c;-webkit-box-decoration-break:clone;box-decoration-break:clone;padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.wp-block-kadence-advancedheading.kt-adv-heading_654ebe-22 img.kb-inline-image, .wp-block-kadence-advancedheading.kt-adv-heading_654ebe-22[data-kb-block=\"kb-adv-heading_654ebe-22\"] img.kb-inline-image{width:150px;vertical-align:baseline;}<\/style>\n<div class=\"kt-adv-heading_654ebe-22 summary-title wp-block-kadence-advancedheading\" data-kb-block=\"kb-adv-heading_654ebe-22\"><span>Summary<\/span><\/div>\n\n\n\n<ul class=\"wp-block-list\"><li>DTC P0641 stands for &ldquo;Sensor Reference Voltage &ldquo;A&rdquo; Circuit\/Open.&rdquo; It&rsquo;s triggered when the PCM detects voltage that doesn&rsquo;t match manufacturer specifications on the 5-volt reference circuit.<\/li><li>Code P0641 is typically caused by malfunctioning sensors, wiring issues, and PCM problems.<\/li><li>The most common symptoms of P0641 include a lit check engine light and sensor issues.<\/li><\/ul>\n<\/div><\/div>\n<\/div><\/div><\/div>\n<\/div><\/div>\n\n\n\n\n\n<p>Trouble codes formatted P06xx (xx being other numbers) always point to an issue within the <a href=\"https:\/\/www.carparts.com\/engine-control-module\" target=\"_blank\" rel=\"noreferrer noopener\" aria-label=\"ECM\/PCM\">ECM\/PCM<\/a> or in a related circuit specific to it.<\/p>\n\n\n\n<p>If a problem in the reference circuit is detected, the computer stores code P0641. If you&rsquo;ve retrieved this code from your vehicle, here is some basic information that you should know.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What Does the P0641 Code Mean?<\/h2>\n\n\n\n<p>Diagnostic trouble code (DTC) P0641 stands for &ldquo;Sensor Reference Voltage &ldquo;A&rdquo; Circuit\/Open.&rdquo; It is logged whenever the PCM detects voltage that does not match manufacturer specifications on the 5-volt reference circuit.<\/p>\n\n\n\n<p>If the 5 volts feeding the three-wire sensors is shorted to ground, it pulls all the three-wire sensor voltages to zero, and on some vehicles (like Fords), it will put the PCM to sleep so that there is no spark, fuel injection, or communication with the scan tool; thus there is no DTC for a shorted 5 volt rail on a system where the ECM\/PCM has just one 5 volt rail because the ECM\/PCM can&rsquo;t communicate anyway.&nbsp;<\/p>\n\n\n\n<p>If, however, there are <strong>multiple 5 volt rails<\/strong>, a short on just one of the rails won&rsquo;t disable the engine. On a Ford, if any three-wire sensor shorts out, it kills the whole system. On a system with multiple rails, only one system goes down, but the engine will still run, albeit in <a href=\"https:\/\/www.carparts.com\/blog\/web-stories\/what-is-limp-mode\/\" target=\"_blank\" rel=\"noreferrer noopener\" aria-label=\"limp mode\">limp mode<\/a> (usually).<\/p>\n\n\n\n<p>A <strong>2016 Chevy Silverado<\/strong>, for example, has <strong>five different 5 volt rails<\/strong>. A short on any of these five rails will cause a different code to be set for each rail. The 5 volt rails on the Silverado each feed a different set of sensors.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/07\/Electric-transmission-control-module-designed-for-automatic-transmission-1024x789.jpg\" alt=\"Electric transmission control module designed for automatic transmission\" class=\"wp-image-42267\" width=\"1024\" height=\"789\" srcset=\"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/07\/Electric-transmission-control-module-designed-for-automatic-transmission-1024x789.jpg 1024w, https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/07\/Electric-transmission-control-module-designed-for-automatic-transmission-300x231.jpg 300w, https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/07\/Electric-transmission-control-module-designed-for-automatic-transmission-768x592.jpg 768w, https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/07\/Electric-transmission-control-module-designed-for-automatic-transmission-1536x1184.jpg 1536w, https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/07\/Electric-transmission-control-module-designed-for-automatic-transmission-150x116.jpg 150w, https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/07\/Electric-transmission-control-module-designed-for-automatic-transmission.jpg 1700w\" sizes=\"(max-width: 1024px) 100vw, 1024px\"><figcaption>P0641 code is logged whenever the PCM detects voltage that does not match manufacturer specifications on the 5-volt reference circuit.<\/figcaption><\/figure>\n\n\n\n<p><strong>Rail 1<\/strong> feeds the Engine Oil Pressure Sensor, the Fuel Rail Pressure Sensor, the A\/C refrigerant pressure sensor, the Exhaust Pressure Differential sensor, the Camshaft Position Sensor. A short on this rail will set code P0641.<\/p>\n\n\n\n<p>The other four 5 volt rails set different codes.<\/p>\n\n\n\n<p><strong>Rail 2<\/strong> feeds Accelerator Pedal Sensor 2, the <a href=\"https:\/\/www.carparts.com\/blog\/is-it-safe-to-drive-with-a-bad-map-sensor\/\" target=\"_blank\" rel=\"noreferrer noopener\" aria-label=\"MAP sensor\">MAP sensor<\/a>, and the Brake Pedal Position Sensor. That rail will set a P0651 if it shorts out.<\/p>\n\n\n\n<p><strong>Rail 3<\/strong> feeds Accelerator Pedal Sensor 1 and the Intake Air Valve Position Sensor. That rail sets a DTC&thinsp;P0697.<\/p>\n\n\n\n<p><strong>Rail 4<\/strong> feeds the EGR position sensor. That rail sets a DTC DTC&thinsp;P06A3.<\/p>\n\n\n\n<p><strong>Rail 5<\/strong> feeds the Crank Position Sensor, The Cooling Fan Speed Sensor, the DEF fluid pressure sensor, and the Turbocharger Vane Position Sensor. That rail sets a DTC&thinsp;P06D2.<\/p>\n\n\n\n<p>For an advanced, technical discussion of two-wire vs three-wire sensors and reference voltage, you can read our explanation <a href=\"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuitopen\/#Two-Wire_vs_Three-Wire_Sensors_and_Reference_Voltage\" target=\"_blank\" rel=\"noreferrer noopener\" aria-label=\"here\">here<\/a>.<\/p>\n\n\n\n<p><strong>Note:<\/strong> The definition of code P0641 may be different depending on the vehicle manufacturer. Consult the <a href=\"https:\/\/www.carparts.com\/blog\/why-you-should-always-consult-a-repair-manual\/\" target=\"_blank\" rel=\"noreferrer noopener\" aria-label=\"appropriate repair manual or repair database\">appropriate repair manual or repair database<\/a> for the exact code definition.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What are the Possible Causes of the P0641 Code?<\/h2>\n\n\n\n<figure class=\"wp-block-image size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/07\/engine-control-unit-or-ECU-of-a-car-with-multicolored-wires-plug-at-foreground-1024x683.jpg\" alt=\"engine control unit or ECU of a car with multicolored wires plug at foreground\" class=\"wp-image-42263\" width=\"1024\" height=\"683\" srcset=\"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/07\/engine-control-unit-or-ECU-of-a-car-with-multicolored-wires-plug-at-foreground-1024x683.jpg 1024w, https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/07\/engine-control-unit-or-ECU-of-a-car-with-multicolored-wires-plug-at-foreground-300x200.jpg 300w, https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/07\/engine-control-unit-or-ECU-of-a-car-with-multicolored-wires-plug-at-foreground-768x512.jpg 768w, https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/07\/engine-control-unit-or-ECU-of-a-car-with-multicolored-wires-plug-at-foreground-1536x1024.jpg 1536w, https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/07\/engine-control-unit-or-ECU-of-a-car-with-multicolored-wires-plug-at-foreground-scaled.jpg 2048w, https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/07\/engine-control-unit-or-ECU-of-a-car-with-multicolored-wires-plug-at-foreground-600x400.jpg 600w, https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/07\/engine-control-unit-or-ECU-of-a-car-with-multicolored-wires-plug-at-foreground-150x100.jpg 150w\" sizes=\"(max-width: 1024px) 100vw, 1024px\"><figcaption>Wiring or connection issues can cause the P0641 code.<\/figcaption><\/figure>\n\n\n\n<p>The code P0641 can be triggered by various issues, including:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Malfunctioning sensor<\/li><li>Wiring or connection issues<\/li><li>PCM problems<\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">What are the Common Symptoms of the P0641 Code?<\/h2>\n\n\n\n<p>Keep an eye out for these warning signs if you are dealing with a P0641 code:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Check Engine Light is illuminated<\/li><li>Sensor-related performance issues<\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">How to Diagnose the P0641 Code<\/h2>\n\n\n\n<p>Identifying the underlying cause of the P0641<strong> <\/strong>code can be difficult, especially if you&rsquo;re not confident with your automotive knowledge. In most cases, it would be best to bring your vehicle to an auto repair shop and seek the help of a professional for an accurate diagnosis.<\/p>\n\n\n\n<p>Here is a video that can help give you a better idea of how this <a href=\"https:\/\/www.carparts.com\/blog\/search-obd2-codes-list\/\" target=\"_blank\" rel=\"noreferrer noopener\" aria-label=\"trouble code\">trouble code<\/a> might be diagnosed:<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"Troubleshooting a Shorted 5v Reference Circuit (Chevy Silverado)\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/RcQdITo_AOA?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">How to Fix the P0641 Code<\/h2>\n\n\n\n<p>The P0641 code is a generic trouble code that may apply to various makes and models. While vehicles from different manufacturers may share common symptoms, that doesn&rsquo;t mean that they also share repair processes. For example, the steps for diagnosis and repair for a P0641 Chevy code may differ from those required by a P0641 Hyundai code.<\/p>\n\n\n\n<p>If you&rsquo;re an advanced DIYer who&rsquo;d like to fix this code on your own, it will be helpful to refer to your repair manual or get factory vehicle repair information from an online subscription service.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Two-Wire vs Three-Wire Sensors and Reference Voltage<\/h2>\n\n\n\n<p>Like any computer, the ECM\/PCM performs its calculations using inputs and outputs. Some sensors, like conventional zirconia O2 sensors, produce their own voltage on most systems. Two-wire speed sensors of the variable reluctance design (a coil of wire surrounding a magnet with teeth passing by the magnet) also produce their own voltage in an AC waveform.<\/p>\n\n\n\n<p>But many engine control system sensors receive a constant regulated voltage input from the ECM\/PCM. Some sensors have a dedicated reference voltage feed (these are two-wire thermistors that measure temperature of coolant, transmission fluid, or air), and other sensors have three wires and share the same reference voltage, which is typically 5 volts. Three-wire sensors that share the same 5 volts are typically potentiometers such as accelerator pedal and throttle position sensors.<\/p>\n\n\n\n<div id=\"article-search-widget\">\n<div class=\"cp-search\">\n<div align=\"center\">\n<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/cld.partsimg.com\/image\/upload\/w_auto,dpr_auto\/carparts\/logos\/badge_wordmark\/full_color\/CP_LOGO_COLOUR_RGB\" alt=\"CarParts.com\" width=\"300\" height=\"56\">\n<\/div>\n<form id=\"cpsearchform\" name=\"cpsearchform\" action=\"https:\/\/www.carparts.com\/search\" method=\"get\" target=\"_blank\" accept-charset=\"character_set\" aria-label=\"search CarParts.com\">\n    <input type=\"text\" class=\"keyword\" name=\"q\" placeholder=\"Search for parts on CarParts.com\" value=\"\" aria-label=\"Search CarParts.com\"><input type=\"submit\" class=\"btn-search\" value=\"Search\" aria-label=\"Search\">\n<\/form>\n<\/div>\n<\/div>\n\n\n\n<p>Inside the ECM\/PCM, there is at least one regulated 5 volt rail. Each two-wire thermistor has both wires connected to the ECM\/PCM; one is a ground Ford likes to call &ldquo;Signal Return,&rdquo; but all vehicle systems have a ground like this feeding the sensors from the PCM and this ground is usually shared by all of the sensors.<\/p>\n\n\n\n<p>The other wire on a two-wire sensor receives a 4.6 volts feed that is partially shorted to ground by the thermistor depending on the temperature of that sensor.<\/p>\n\n\n\n<p>Each of these two-wire sensors has its own dedicated feed that comes from a 5 volt rail through a resistor within the ECM\/PCM to prevent the changing resistance of the thermistor from deflecting the 5 volts supplied by the ECM\/PCM&rsquo;s 5 volt rail. The ECM\/PCM measures the voltage between the thermistor and the resistor within the ECM\/PCM to determine the temperature input from that sensor.<\/p>\n\n\n\n<p>Okay, so that brings us to the three-wire sensors. Three wire sensors receive 5 volts from the ECM\/PCM&rsquo;s internal rail on one wire, a ground on another wire, and between these two wires is the signal wire that provides input. Typically a three-wire sensor is used to provide the ECM\/PCM with the position of whatever is being measured, like the accelerator pedal or the throttle plate. Three-wire sensors also measure pressure (like fuel tank pressure and fuel rail pressure or EGR differential pressure).<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Products Mentioned in this Guide<\/h2>\n\n\n\n<div class=\"reusable-productlink\">\n\n<!-- start of editable content -->\n\n<a href=\"https:\/\/www.carparts.com\/engine-control-module\" target=\"_blank\" aria-label=\"Engine Control Module\" rel=\"noopener\">\n<img decoding=\"async\" src=\"https:\/\/cld.partsimg.com\/image\/upload\/d_noimage.jpg,h_200,w_200,c_pad,f_auto,q_auto,dpr_auto,e_sharpen\/images\/a1790044v_1\">\n<strong>Engine Control Module<\/strong>\n<\/a>\n\n<a href=\"https:\/\/www.carparts.com\/oil-pressure-sensor\" target=\"_blank\" aria-label=\"Oil Pressure Sensor\" rel=\"noopener\">\n<img decoding=\"async\" src=\"https:\/\/cld.partsimg.com\/image\/upload\/d_noimage.jpg,h_200,w_200,c_pad,f_auto,q_auto,dpr_auto,e_sharpen\/images\/rh38660001_1\">\n<strong>Oil Pressure Sensor<\/strong>\n<\/a>\n\n<a href=\"https:\/\/www.carparts.com\/fuel-rail-pressure-sensor\" target=\"_blank\" aria-label=\"Fuel Rail Pressure Sensor\" rel=\"noopener\">\n<img decoding=\"async\" src=\"https:\/\/cld.partsimg.com\/image\/upload\/d_noimage.jpg,h_200,w_200,c_pad,f_auto,q_auto,dpr_auto,e_sharpen\/images\/ac12673824_1\">\n<strong>Fuel Rail Pressure Sensor<\/strong>\n<\/a>\n\n<a href=\"https:\/\/www.carparts.com\/a-c-refrigerant-pressure-sensor\" target=\"_blank\" aria-label=\"A\/C Refrigerant Pressure Sensor\" rel=\"noopener\">\n<img decoding=\"async\" src=\"https:\/\/cld.partsimg.com\/image\/upload\/d_noimage.jpg,h_200,w_200,c_pad,f_auto,q_auto,dpr_auto,e_sharpen\/images\/fbi18082_1\">\n<strong>A\/C Refrigerant Pressure Sensor<\/strong>\n<\/a>\n\n<a href=\"https:\/\/www.carparts.com\/camshaft-position-sensor\" target=\"_blank\" aria-label=\"Camshaft Position Sensor\" rel=\"noopener\">\n<img decoding=\"async\" src=\"https:\/\/cld.partsimg.com\/image\/upload\/d_noimage.jpg,h_200,w_200,c_pad,f_auto,q_auto,dpr_auto,e_sharpen\/images\/repn311602_1\">\n<strong>Camshaft Position Sensor<\/strong>\n<\/a>\n\n<a href=\"https:\/\/www.carparts.com\/map-sensor\" target=\"_blank\" aria-label=\"MAP Sensor\" rel=\"noopener\">\n<img decoding=\"async\" src=\"https:\/\/cld.partsimg.com\/image\/upload\/d_noimage.jpg,h_200,w_200,c_pad,f_auto,q_auto,dpr_auto,e_sharpen\/images\/rb31520003_1\">\n<strong>MAP Sensor<\/strong>\n<\/a>\n\n<!-- end of editable content -->\n\n<\/div>\n<\/body><\/html>\n","protected":false},"excerpt":{"rendered":"<p><span class=\"span-reading-time rt-reading-time\" style=\"display: block;\"><span class=\"rt-label rt-prefix\">Reading Time: <\/span> <span class=\"rt-time\"> 5<\/span> <span class=\"rt-label rt-postfix\">minutes<\/span><\/span>Trouble codes formatted P06xx (xx being other numbers) always point to an issue within the ECM\/PCM or in a related&#8230; <a href=\"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/\" rel=\"nofollow\">Read More<\/a><\/p>\n","protected":false},"author":4,"featured_media":16225,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[1314],"tags":[1323,1463],"ppma_author":[2607,2985],"class_list":{"0":"post-16220","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-obd-ii-trouble-codes","8":"tag-engine-control-module-2","9":"tag-fuel-pressure-sensor","10":"entry"},"acf":{"adrotate_specific_mobile_ad":"","adrotate_specific_desktop_ad":""},"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.5 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>P0641 Code: Sensor Reference Voltage &quot;A&quot; Circuit\/Open - In The Garage with CarParts.com<\/title>\n<meta name=\"description\" content=\"Find out what the diagnostic trouble code P0641 means, why it sets, and how it affects the operation of your vehicle with this informative guide.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"P0641 Code: Sensor Reference Voltage &quot;A&quot; Circuit\/Open - In The Garage with CarParts.com\" \/>\n<meta property=\"og:description\" content=\"Find out what the diagnostic trouble code P0641 means, why it sets, and how it affects the operation of your vehicle with this informative guide.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/\" \/>\n<meta property=\"og:site_name\" content=\"In The Garage with CarParts.com\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/carpartscom\" \/>\n<meta property=\"article:published_time\" content=\"2021-07-30T07:25:00+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2024-05-28T04:15:13+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2020\/09\/electronic-engine-control-module.jpeg\" \/>\n\t<meta property=\"og:image:width\" content=\"1500\" \/>\n\t<meta property=\"og:image:height\" content=\"1378\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@carpartscom\" \/>\n<meta name=\"twitter:site\" content=\"@carpartscom\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"7 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/p0641-code-sensor-reference-voltage-a-circuit-open\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/p0641-code-sensor-reference-voltage-a-circuit-open\\\/\"},\"author\":[{\"@type\":\"Person\",\"$id\":\"4\",\"name\":\"CarParts.com Research Team\",\"jobTitle\":\"Expert Automotive Writer\",\"description\":\"The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com&#039;s thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.\",\"knowsAbout\":\"Auto Repair, Car Maintenance, Auto Parts, Car Reviews\",\"publishingPrinciples\":\"\\\/blog\\\/our-team\\\/\",\"url\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/author\\\/thecpteam\\\/\",\"sameAs\":\"https:\\\/\\\/www.facebook.com\\\/carpartscom, https:\\\/\\\/twitter.com\\\/CarPartscom, https:\\\/\\\/www.youtube.com\\\/@CarPartscomOfficial\\\/, https:\\\/\\\/www.instagram.com\\\/carpartscom\\\/\"},{\"@type\":\"Person\",\"$id\":\"4\",\"name\":\"Richard McCuistian\",\"jobTitle\":\"ASE Master Automobile Technician\",\"description\":\"Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.\",\"knowsAbout\":\"Auto Repair, Car Maintenance, Auto Parts, Car Reviews\",\"publishingPrinciples\":\"\\\/blog\\\/our-team\\\/\",\"url\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/author\\\/richardmccuistian\\\/\",\"sameAs\":\"https:\\\/\\\/www.linkedin.com\\\/in\\\/richard-mccuistian-2681891b\\\/, https:\\\/\\\/www.youtube.com\\\/user\\\/McCuistian\"}],\"headline\":\"P0641 Code: Sensor Reference Voltage &#8220;A&#8221; Circuit\\\/Open\",\"datePublished\":\"2021-07-30T07:25:00+00:00\",\"dateModified\":\"2024-05-28T04:15:13+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/p0641-code-sensor-reference-voltage-a-circuit-open\\\/\"},\"wordCount\":1183,\"commentCount\":15,\"publisher\":{\"@id\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/p0641-code-sensor-reference-voltage-a-circuit-open\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/wp-content\\\/uploads\\\/2020\\\/09\\\/electronic-engine-control-module.jpeg\",\"keywords\":[\"engine-control-module\",\"fuel-pressure-sensor\"],\"articleSection\":[\"OBD-II Trouble Codes\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/www.carparts.com\\\/blog\\\/p0641-code-sensor-reference-voltage-a-circuit-open\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/p0641-code-sensor-reference-voltage-a-circuit-open\\\/\",\"url\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/p0641-code-sensor-reference-voltage-a-circuit-open\\\/\",\"name\":\"P0641 Code: Sensor Reference Voltage \\\"A\\\" Circuit\\\/Open - In The Garage with CarParts.com\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/p0641-code-sensor-reference-voltage-a-circuit-open\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/p0641-code-sensor-reference-voltage-a-circuit-open\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/wp-content\\\/uploads\\\/2020\\\/09\\\/electronic-engine-control-module.jpeg\",\"datePublished\":\"2021-07-30T07:25:00+00:00\",\"dateModified\":\"2024-05-28T04:15:13+00:00\",\"description\":\"Find out what the diagnostic trouble code P0641 means, why it sets, and how it affects the operation of your vehicle with this informative guide.\",\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/www.carparts.com\\\/blog\\\/p0641-code-sensor-reference-voltage-a-circuit-open\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/p0641-code-sensor-reference-voltage-a-circuit-open\\\/#primaryimage\",\"url\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/wp-content\\\/uploads\\\/2020\\\/09\\\/electronic-engine-control-module.jpeg\",\"contentUrl\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/wp-content\\\/uploads\\\/2020\\\/09\\\/electronic-engine-control-module.jpeg\",\"width\":1500,\"height\":1378,\"caption\":\"electronic engine control module\"},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/#website\",\"url\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/\",\"name\":\"In The Garage with CarParts.com\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/#organization\",\"name\":\"CarParts.com\",\"url\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/wp-content\\\/uploads\\\/2025\\\/03\\\/cp-itg-logo.png\",\"contentUrl\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/wp-content\\\/uploads\\\/2025\\\/03\\\/cp-itg-logo.png\",\"width\":2048,\"height\":398,\"caption\":\"CarParts.com\"},\"image\":{\"@id\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/carpartscom\",\"https:\\\/\\\/x.com\\\/carpartscom\",\"https:\\\/\\\/www.instagram.com\\\/carpartscom\",\"https:\\\/\\\/www.youtube.com\\\/@CarPartscomOfficial\\\/\"]},{\"@type\":\"Person\",\"@id\":\"\",\"url\":\"https:\\\/\\\/www.carparts.com\\\/blog\\\/p0641-code-sensor-reference-voltage-a-circuit-open\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"P0641 Code: Sensor Reference Voltage \"A\" Circuit\/Open - In The Garage with CarParts.com","description":"Find out what the diagnostic trouble code P0641 means, why it sets, and how it affects the operation of your vehicle with this informative guide.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/","og_locale":"en_US","og_type":"article","og_title":"P0641 Code: Sensor Reference Voltage \"A\" Circuit\/Open - In The Garage with CarParts.com","og_description":"Find out what the diagnostic trouble code P0641 means, why it sets, and how it affects the operation of your vehicle with this informative guide.","og_url":"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/","og_site_name":"In The Garage with CarParts.com","article_publisher":"https:\/\/www.facebook.com\/carpartscom","article_published_time":"2021-07-30T07:25:00+00:00","article_modified_time":"2024-05-28T04:15:13+00:00","og_image":[{"width":1500,"height":1378,"url":"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2020\/09\/electronic-engine-control-module.jpeg","type":"image\/jpeg"}],"twitter_card":"summary_large_image","twitter_creator":"@carpartscom","twitter_site":"@carpartscom","twitter_misc":{"Written by":"","Est. reading time":"7 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/#article","isPartOf":{"@id":"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/"},"author":[{"@type":"Person","$id":"4","name":"CarParts.com Research Team","jobTitle":"Expert Automotive Writer","description":"The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com&#039;s thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.","knowsAbout":"Auto Repair, Car Maintenance, Auto Parts, Car Reviews","publishingPrinciples":"\/blog\/our-team\/","url":"https:\/\/www.carparts.com\/blog\/author\/thecpteam\/","sameAs":"https:\/\/www.facebook.com\/carpartscom, https:\/\/twitter.com\/CarPartscom, https:\/\/www.youtube.com\/@CarPartscomOfficial\/, https:\/\/www.instagram.com\/carpartscom\/"},{"@type":"Person","$id":"4","name":"Richard McCuistian","jobTitle":"ASE Master Automobile Technician","description":"Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.","knowsAbout":"Auto Repair, Car Maintenance, Auto Parts, Car Reviews","publishingPrinciples":"\/blog\/our-team\/","url":"https:\/\/www.carparts.com\/blog\/author\/richardmccuistian\/","sameAs":"https:\/\/www.linkedin.com\/in\/richard-mccuistian-2681891b\/, https:\/\/www.youtube.com\/user\/McCuistian"}],"headline":"P0641 Code: Sensor Reference Voltage &#8220;A&#8221; Circuit\/Open","datePublished":"2021-07-30T07:25:00+00:00","dateModified":"2024-05-28T04:15:13+00:00","mainEntityOfPage":{"@id":"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/"},"wordCount":1183,"commentCount":15,"publisher":{"@id":"https:\/\/www.carparts.com\/blog\/#organization"},"image":{"@id":"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/#primaryimage"},"thumbnailUrl":"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2020\/09\/electronic-engine-control-module.jpeg","keywords":["engine-control-module","fuel-pressure-sensor"],"articleSection":["OBD-II Trouble Codes"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/","url":"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/","name":"P0641 Code: Sensor Reference Voltage \"A\" Circuit\/Open - In The Garage with CarParts.com","isPartOf":{"@id":"https:\/\/www.carparts.com\/blog\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/#primaryimage"},"image":{"@id":"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/#primaryimage"},"thumbnailUrl":"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2020\/09\/electronic-engine-control-module.jpeg","datePublished":"2021-07-30T07:25:00+00:00","dateModified":"2024-05-28T04:15:13+00:00","description":"Find out what the diagnostic trouble code P0641 means, why it sets, and how it affects the operation of your vehicle with this informative guide.","inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/#primaryimage","url":"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2020\/09\/electronic-engine-control-module.jpeg","contentUrl":"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2020\/09\/electronic-engine-control-module.jpeg","width":1500,"height":1378,"caption":"electronic engine control module"},{"@type":"WebSite","@id":"https:\/\/www.carparts.com\/blog\/#website","url":"https:\/\/www.carparts.com\/blog\/","name":"In The Garage with CarParts.com","description":"","publisher":{"@id":"https:\/\/www.carparts.com\/blog\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.carparts.com\/blog\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/www.carparts.com\/blog\/#organization","name":"CarParts.com","url":"https:\/\/www.carparts.com\/blog\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.carparts.com\/blog\/#\/schema\/logo\/image\/","url":"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2025\/03\/cp-itg-logo.png","contentUrl":"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2025\/03\/cp-itg-logo.png","width":2048,"height":398,"caption":"CarParts.com"},"image":{"@id":"https:\/\/www.carparts.com\/blog\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/carpartscom","https:\/\/x.com\/carpartscom","https:\/\/www.instagram.com\/carpartscom","https:\/\/www.youtube.com\/@CarPartscomOfficial\/"]},{"@type":"Person","@id":"","url":"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/"}]}},"featured_image_src":"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2020\/09\/electronic-engine-control-module.jpeg","featured_image_src_square":"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2020\/09\/electronic-engine-control-module.jpeg","author_info":{"display_name":"","author_link":"https:\/\/www.carparts.com\/blog\/p0641-code-sensor-reference-voltage-a-circuit-open\/"},"authors":[{"term_id":2607,"user_id":1651,"is_guest":0,"slug":"thecpteam","display_name":"CarParts.com Research Team","avatar_url":{"url":"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2024\/04\/thecpteam.jpg","url2x":"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2024\/04\/thecpteam.jpg"},"0":null,"1":"","2":"","3":"","4":"","5":"","6":"","7":"","8":""},{"term_id":2985,"user_id":1646,"is_guest":0,"slug":"richardmccuistian","display_name":"Richard McCuistian, ASE Certified Master Automobile Technician","avatar_url":{"url":"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/11\/richard-mccuistian.png","url2x":"https:\/\/www.carparts.com\/blog\/wp-content\/uploads\/2021\/11\/richard-mccuistian.png"},"0":null,"1":"","2":"","3":"","4":"","5":"","6":"","7":"","8":""}],"_links":{"self":[{"href":"https:\/\/www.carparts.com\/blog\/wp-json\/wp\/v2\/posts\/16220","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.carparts.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.carparts.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.carparts.com\/blog\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.carparts.com\/blog\/wp-json\/wp\/v2\/comments?post=16220"}],"version-history":[{"count":0,"href":"https:\/\/www.carparts.com\/blog\/wp-json\/wp\/v2\/posts\/16220\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.carparts.com\/blog\/wp-json\/wp\/v2\/media\/16225"}],"wp:attachment":[{"href":"https:\/\/www.carparts.com\/blog\/wp-json\/wp\/v2\/media?parent=16220"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.carparts.com\/blog\/wp-json\/wp\/v2\/categories?post=16220"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.carparts.com\/blog\/wp-json\/wp\/v2\/tags?post=16220"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.carparts.com\/blog\/wp-json\/wp\/v2\/ppma_author?post=16220"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}