{"id":991,"date":"2026-04-12T15:07:50","date_gmt":"2026-04-12T19:07:50","guid":{"rendered":"https:\/\/www.4roadservice.com\/resources\/?page_id=991"},"modified":"2026-04-12T15:07:51","modified_gmt":"2026-04-12T19:07:51","slug":"detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited","status":"publish","type":"page","link":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/","title":{"rendered":"SPN 4766 FMI 31 \u2013 DPF Active Regeneration Inhibited"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-fault-codes-dd13-dd15-dd16\/\">\u2190 Back to Detroit Diesel Fault Codes<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Detroit Diesel SPN 4766 FMI 31 indicates that the DPF active regeneration process is being prevented from initiating or completing due to a system condition or fault. This code appears on DD13, DD15, and DD16 engines and means the ECM has determined that conditions are not safe or suitable for active regeneration to proceed. With regeneration blocked soot will continue to accumulate in the DPF leading to progressively more severe fault codes.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Symptoms<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Check engine light on <\/li>\n\n\n\n<li>DPF or regen warning light illuminated <\/li>\n\n\n\n<li>Active regeneration not initiating <\/li>\n\n\n\n<li>DPF soot load continuing to rise <\/li>\n\n\n\n<li>Engine derate possible as soot accumulates <\/li>\n\n\n\n<li>Regen inhibit indicator may be illuminated on dash<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Cause<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">This code triggers when the ECM determines one or more conditions are preventing active regeneration from proceeding. Common causes include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Regen inhibit switch manually activated by driver <\/li>\n\n\n\n<li>Active fault codes preventing regeneration from initiating <\/li>\n\n\n\n<li>Low fuel level preventing regen from starting <\/li>\n\n\n\n<li>Engine operating conditions outside regen parameters <\/li>\n\n\n\n<li>Faulty regen related sensor preventing ECM from approving regen <\/li>\n\n\n\n<li>Parking brake not applied during attempted parked regen <\/li>\n\n\n\n<li>Multiple active fault codes creating inhibit conditions <\/li>\n\n\n\n<li>HC dosing system fault preventing regen from being approved<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Can You Keep Driving?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Limited driving is possible but with active regeneration inhibited soot will continue to build in the DPF. If the inhibit condition is not resolved the DPF will reach critical soot levels triggering more severe derate conditions. Identify and resolve the inhibit cause as soon as possible.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Recommended Action<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">First check if the regen inhibit switch is activated and turn it off if so. Check fuel level and top up if low. Clear any active fault codes that may be creating inhibit conditions and attempt a parked regeneration. If regeneration remains inhibited have the HC dosing system, regen related sensors, and ECM conditions evaluated by a qualified diesel technician.<\/p>\n\n\n\n<div class=\"schema-faq wp-block-yoast-faq-block\"><div class=\"schema-faq-section\" id=\"faq-question-1776020580944\"><strong class=\"schema-faq-question\">What does Detroit Diesel SPN 4766 FMI 31 mean?<\/strong> <p class=\"schema-faq-answer\">It means the ECM is preventing active DPF regeneration from proceeding due to a system condition or fault that makes regeneration unsafe or impossible under current conditions.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1776020582797\"><strong class=\"schema-faq-question\"><strong>What causes SPN 4766 FMI 31?<\/strong><\/strong> <p class=\"schema-faq-answer\">The most common causes are the regen inhibit switch being active, low fuel level, active fault codes creating inhibit conditions, or a faulty sensor preventing the ECM from approving regeneration.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1776020582445\"><strong class=\"schema-faq-question\">Can I keep driving with SPN 4766 FMI 31?<\/strong> <p class=\"schema-faq-answer\">Short distances may be possible but with regeneration inhibited soot will accumulate and more severe DPF faults will follow. Resolve the inhibit condition as soon as possible.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1776020582141\"><strong class=\"schema-faq-question\">Will SPN 4766 FMI 31 cause a derate?<\/strong> <p class=\"schema-faq-answer\">Not immediately but as soot accumulates from blocked regeneration more severe DPF soot codes will trigger derate conditions.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1776020581788\"><strong class=\"schema-faq-question\">How do I clear SPN 4766 FMI 31?<\/strong> <p class=\"schema-faq-answer\">Identify and resolve the condition inhibiting regeneration \u2014 check the inhibit switch, fuel level, and any active fault codes. Once the inhibit condition is cleared and a successful active regeneration completes the code should clear.<\/p> <\/div> <\/div>\n\n\n\n<h2 class=\"wp-block-heading\">Related codes<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-3826-fmi-16-dpf-incomplete-regeneration\/\" type=\"link\" id=\"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-3826-fmi-16-dpf-incomplete-regeneration\/\">SPN 3826 FMI 16 <\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-3713-fmi-16-dpf-soot-load-high\/\" type=\"link\" id=\"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-3713-fmi-16-dpf-soot-load-high\/\">SPN 3713 FMI 16 <\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-3713-fmi-18-dpf-soot-load-critical\/\" type=\"link\" id=\"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-3713-fmi-18-dpf-soot-load-critical\/\">SPN 3713 FMI 18 <\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-3719-fmi-0\/\" type=\"link\" id=\"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-3719-fmi-0\/\">SPN 3719 FMI 0 <\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-3556-fmi-16-hydrocarbon-dosing-injector-fault\/\" type=\"link\" id=\"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-3556-fmi-16-hydrocarbon-dosing-injector-fault\/\">SPN 3556 FMI 16<\/a><\/li>\n<\/ul>\n\n\n\n<div class=\"wp-block-group\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<h2 class=\"wp-block-heading\">Need Immediate Help With This Fault Code?<\/h2>\n<\/div><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">If your engine is derating, losing power, or unable to complete regeneration, don\u2019t risk further damage or costly downtime.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Use 4RoadService to locate mobile truck repair, dealer diagnostics, or emergency roadside assistance near your location.<\/p>\n\n\n\n<div class=\"wp-block-buttons has-off-white-background-color has-background is-content-justification-center is-layout-flex wp-container-core-buttons-is-layout-fe48e5de wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button\"><a class=\"wp-block-button__link wp-element-button\" href=\"https:\/\/www.4roadservice.com\/truck-dealers\">Find Truck Repair Near Me<\/a><\/div>\n\n\n\n<div class=\"wp-block-button\"><a class=\"wp-block-button__link has-text-align-center wp-element-button\" href=\"https:\/\/www.4roadservice.com\/truck-repair\">Find Mobile Road Service<\/a><\/div>\n<\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Important Notice<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The information provided above is for general informational purposes only and should not replace official OEM service procedures. Always consult the manufacturer\u2019s service manual or a qualified diesel technician before performing repairs. Operating a vehicle with active fault codes may result in further damage.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u2190 Back to Detroit Diesel Fault Codes Detroit Diesel SPN 4766 FMI 31 indicates that the DPF active regeneration process is being prevented from initiating or completing due to a system condition or fault. This code appears on DD13, DD15, and DD16 engines and means the ECM has determined that conditions are not safe or &hellip; <a href=\"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">SPN 4766 FMI 31 \u2013 DPF Active Regeneration Inhibited<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-991","page","type-page","status-publish","hentry"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.1 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>SPN 4766 FMI 31 \u2013 DPF Active Regeneration Inhibited<\/title>\n<meta name=\"description\" content=\"Detroit Diesel SPN 4766 FMI 31 means DPF active regeneration is being inhibited. Learn symptoms, causes, derate risk and how to fix it.\" \/>\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.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"SPN 4766 FMI 31 \u2013 DPF Active Regeneration Inhibited\" \/>\n<meta property=\"og:description\" content=\"Detroit Diesel SPN 4766 FMI 31 means DPF active regeneration is being inhibited. Learn symptoms, causes, derate risk and how to fix it.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/\" \/>\n<meta property=\"og:site_name\" content=\"4RoadService Resources\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/4roadservice\" \/>\n<meta property=\"article:modified_time\" content=\"2026-04-12T19:07:51+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.4roadservice.com\/resources\/wp-content\/uploads\/2015\/08\/logo-sidebar@2x.png\" \/>\n\t<meta property=\"og:image:width\" content=\"380\" \/>\n\t<meta property=\"og:image:height\" content=\"64\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:site\" content=\"@4RoadService\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"3 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":[\"WebPage\",\"FAQPage\"],\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/\",\"url\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/\",\"name\":\"SPN 4766 FMI 31 \u2013 DPF Active Regeneration Inhibited\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/#website\"},\"datePublished\":\"2026-04-12T19:07:50+00:00\",\"dateModified\":\"2026-04-12T19:07:51+00:00\",\"description\":\"Detroit Diesel SPN 4766 FMI 31 means DPF active regeneration is being inhibited. Learn symptoms, causes, derate risk and how to fix it.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#breadcrumb\"},\"mainEntity\":[{\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#faq-question-1776020580944\"},{\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#faq-question-1776020582797\"},{\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#faq-question-1776020582445\"},{\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#faq-question-1776020582141\"},{\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#faq-question-1776020581788\"}],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"SPN 4766 FMI 31 \u2013 DPF Active Regeneration Inhibited\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/#website\",\"url\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/\",\"name\":\"4RoadService Resources\",\"description\":\"Tools, Repairs &amp; Resources for Truck Drivers\",\"publisher\":{\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/#organization\",\"name\":\"4RoadService.com\",\"url\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/blog.4roadservice.com\\\/wp-content\\\/uploads\\\/2015\\\/08\\\/logo-sidebar@2x.png\",\"contentUrl\":\"https:\\\/\\\/blog.4roadservice.com\\\/wp-content\\\/uploads\\\/2015\\\/08\\\/logo-sidebar@2x.png\",\"width\":380,\"height\":64,\"caption\":\"4RoadService.com\"},\"image\":{\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/4roadservice\",\"https:\\\/\\\/x.com\\\/4RoadService\"]},{\"@type\":\"Question\",\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#faq-question-1776020580944\",\"position\":1,\"url\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#faq-question-1776020580944\",\"name\":\"What does Detroit Diesel SPN 4766 FMI 31 mean?\",\"answerCount\":1,\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"It means the ECM is preventing active DPF regeneration from proceeding due to a system condition or fault that makes regeneration unsafe or impossible under current conditions.\",\"inLanguage\":\"en-US\"},\"inLanguage\":\"en-US\"},{\"@type\":\"Question\",\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#faq-question-1776020582797\",\"position\":2,\"url\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#faq-question-1776020582797\",\"name\":\"What causes SPN 4766 FMI 31?\",\"answerCount\":1,\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"The most common causes are the regen inhibit switch being active, low fuel level, active fault codes creating inhibit conditions, or a faulty sensor preventing the ECM from approving regeneration.\",\"inLanguage\":\"en-US\"},\"inLanguage\":\"en-US\"},{\"@type\":\"Question\",\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#faq-question-1776020582445\",\"position\":3,\"url\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#faq-question-1776020582445\",\"name\":\"Can I keep driving with SPN 4766 FMI 31?\",\"answerCount\":1,\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Short distances may be possible but with regeneration inhibited soot will accumulate and more severe DPF faults will follow. Resolve the inhibit condition as soon as possible.\",\"inLanguage\":\"en-US\"},\"inLanguage\":\"en-US\"},{\"@type\":\"Question\",\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#faq-question-1776020582141\",\"position\":4,\"url\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#faq-question-1776020582141\",\"name\":\"Will SPN 4766 FMI 31 cause a derate?\",\"answerCount\":1,\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Not immediately but as soot accumulates from blocked regeneration more severe DPF soot codes will trigger derate conditions.\",\"inLanguage\":\"en-US\"},\"inLanguage\":\"en-US\"},{\"@type\":\"Question\",\"@id\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#faq-question-1776020581788\",\"position\":5,\"url\":\"https:\\\/\\\/www.4roadservice.com\\\/resources\\\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\\\/#faq-question-1776020581788\",\"name\":\"How do I clear SPN 4766 FMI 31?\",\"answerCount\":1,\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Identify and resolve the condition inhibiting regeneration \u2014 check the inhibit switch, fuel level, and any active fault codes. Once the inhibit condition is cleared and a successful active regeneration completes the code should clear.\",\"inLanguage\":\"en-US\"},\"inLanguage\":\"en-US\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"SPN 4766 FMI 31 \u2013 DPF Active Regeneration Inhibited","description":"Detroit Diesel SPN 4766 FMI 31 means DPF active regeneration is being inhibited. Learn symptoms, causes, derate risk and how to fix it.","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.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/","og_locale":"en_US","og_type":"article","og_title":"SPN 4766 FMI 31 \u2013 DPF Active Regeneration Inhibited","og_description":"Detroit Diesel SPN 4766 FMI 31 means DPF active regeneration is being inhibited. Learn symptoms, causes, derate risk and how to fix it.","og_url":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/","og_site_name":"4RoadService Resources","article_publisher":"https:\/\/www.facebook.com\/4roadservice","article_modified_time":"2026-04-12T19:07:51+00:00","og_image":[{"width":380,"height":64,"url":"https:\/\/www.4roadservice.com\/resources\/wp-content\/uploads\/2015\/08\/logo-sidebar@2x.png","type":"image\/png"}],"twitter_card":"summary_large_image","twitter_site":"@4RoadService","twitter_misc":{"Est. reading time":"3 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":["WebPage","FAQPage"],"@id":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/","url":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/","name":"SPN 4766 FMI 31 \u2013 DPF Active Regeneration Inhibited","isPartOf":{"@id":"https:\/\/www.4roadservice.com\/resources\/#website"},"datePublished":"2026-04-12T19:07:50+00:00","dateModified":"2026-04-12T19:07:51+00:00","description":"Detroit Diesel SPN 4766 FMI 31 means DPF active regeneration is being inhibited. Learn symptoms, causes, derate risk and how to fix it.","breadcrumb":{"@id":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#breadcrumb"},"mainEntity":[{"@id":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#faq-question-1776020580944"},{"@id":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#faq-question-1776020582797"},{"@id":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#faq-question-1776020582445"},{"@id":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#faq-question-1776020582141"},{"@id":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#faq-question-1776020581788"}],"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.4roadservice.com\/resources\/"},{"@type":"ListItem","position":2,"name":"SPN 4766 FMI 31 \u2013 DPF Active Regeneration Inhibited"}]},{"@type":"WebSite","@id":"https:\/\/www.4roadservice.com\/resources\/#website","url":"https:\/\/www.4roadservice.com\/resources\/","name":"4RoadService Resources","description":"Tools, Repairs &amp; Resources for Truck Drivers","publisher":{"@id":"https:\/\/www.4roadservice.com\/resources\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.4roadservice.com\/resources\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/www.4roadservice.com\/resources\/#organization","name":"4RoadService.com","url":"https:\/\/www.4roadservice.com\/resources\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.4roadservice.com\/resources\/#\/schema\/logo\/image\/","url":"https:\/\/blog.4roadservice.com\/wp-content\/uploads\/2015\/08\/logo-sidebar@2x.png","contentUrl":"https:\/\/blog.4roadservice.com\/wp-content\/uploads\/2015\/08\/logo-sidebar@2x.png","width":380,"height":64,"caption":"4RoadService.com"},"image":{"@id":"https:\/\/www.4roadservice.com\/resources\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/4roadservice","https:\/\/x.com\/4RoadService"]},{"@type":"Question","@id":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#faq-question-1776020580944","position":1,"url":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#faq-question-1776020580944","name":"What does Detroit Diesel SPN 4766 FMI 31 mean?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"It means the ECM is preventing active DPF regeneration from proceeding due to a system condition or fault that makes regeneration unsafe or impossible under current conditions.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#faq-question-1776020582797","position":2,"url":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#faq-question-1776020582797","name":"What causes SPN 4766 FMI 31?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"The most common causes are the regen inhibit switch being active, low fuel level, active fault codes creating inhibit conditions, or a faulty sensor preventing the ECM from approving regeneration.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#faq-question-1776020582445","position":3,"url":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#faq-question-1776020582445","name":"Can I keep driving with SPN 4766 FMI 31?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"Short distances may be possible but with regeneration inhibited soot will accumulate and more severe DPF faults will follow. Resolve the inhibit condition as soon as possible.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#faq-question-1776020582141","position":4,"url":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#faq-question-1776020582141","name":"Will SPN 4766 FMI 31 cause a derate?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"Not immediately but as soot accumulates from blocked regeneration more severe DPF soot codes will trigger derate conditions.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#faq-question-1776020581788","position":5,"url":"https:\/\/www.4roadservice.com\/resources\/detroit-diesel-spn-4766-fmi-31-dpf-active-regeneration-inhibited\/#faq-question-1776020581788","name":"How do I clear SPN 4766 FMI 31?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"Identify and resolve the condition inhibiting regeneration \u2014 check the inhibit switch, fuel level, and any active fault codes. Once the inhibit condition is cleared and a successful active regeneration completes the code should clear.","inLanguage":"en-US"},"inLanguage":"en-US"}]}},"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/P6wicq-fZ","_links":{"self":[{"href":"https:\/\/www.4roadservice.com\/resources\/wp-json\/wp\/v2\/pages\/991","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.4roadservice.com\/resources\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.4roadservice.com\/resources\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.4roadservice.com\/resources\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.4roadservice.com\/resources\/wp-json\/wp\/v2\/comments?post=991"}],"version-history":[{"count":4,"href":"https:\/\/www.4roadservice.com\/resources\/wp-json\/wp\/v2\/pages\/991\/revisions"}],"predecessor-version":[{"id":996,"href":"https:\/\/www.4roadservice.com\/resources\/wp-json\/wp\/v2\/pages\/991\/revisions\/996"}],"wp:attachment":[{"href":"https:\/\/www.4roadservice.com\/resources\/wp-json\/wp\/v2\/media?parent=991"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}