In diagnostic messaging, services are the functions. Think of each command as a sentence. The service is the verb. In standard OBDII services are often referred to as Modes. You can also think of them as functions to be performed by the controller(s) that you are commanding.
With diagnostic messages, there is always a command and almost always a response from the controller(s) you are commanding.
When looking at raw CAN Bus data the service is often the second, third, or in very few cases the fourth data byte of the message. In nearly all cases, OEMs will implement ISO 15765-2 (Click Here to read about this protocol). So the service will be the first byte after the Transport Protocol information.<\/p>\n\n\n\n
Here is an example of and OBDII message to get Engine Speed using the CAN Bus ($01 is the Service):
$7DF 02 01 0D 00 00 00 00 00<\/p>\n\n\n\n
Will hopefully return the following:
$7E8 04 41 0D 01 FE 00 00 00<\/p>\n\n\n\n
Here is a simple list of some common Services that you might find:<\/p>\n\n\n\n
OBDII Services (a.k.a. Modes):<\/strong> Services $10 and higher are non-OBDII services also known as Enhanced Diagnostics. This is because, unlike OBDII Diagnostics, these services are not government mandated thus each OEM will use their own specification. For Example GM vehicles use the GMLAN diagnostic protocol. Ford used ISO-14230 but now use ISO-14229 (UDS). Each OEM is can decidedly use their own enhanced diagnostic protocol.<\/p>\n\n\n\n GMLAN Enhanced Services:<\/strong> Here is an example of a CAN Bus message to get the Engine Speed using Enhanced Diagnostics (where $22 is the service): And this will hopefully return: ISO \u2013 14229:<\/strong> Now that you have a list of Services, hopefully this will make reading the raw can data a bit more manageable. Soon I will post more information about specific services themselves. If any are more interesting to you, please post in the comments below.<\/p>\n","protected":false},"excerpt":{"rendered":" In diagnostic messaging, services are the functions. Think of each command as a sentence. The service is the verb. In standard OBDII services are often referred to as Modes. You can also think of them as functions to be performed by the controller(s) that you are commanding.With diagnostic messages, there is always a command and […]<\/p>\n","protected":false},"author":1,"featured_media":388,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[7],"tags":[],"class_list":["post-429","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"_links":{"self":[{"href":"https:\/\/canbushack.com\/web\/wp-json\/wp\/v2\/posts\/429","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/canbushack.com\/web\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/canbushack.com\/web\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/canbushack.com\/web\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/canbushack.com\/web\/wp-json\/wp\/v2\/comments?post=429"}],"version-history":[{"count":0,"href":"https:\/\/canbushack.com\/web\/wp-json\/wp\/v2\/posts\/429\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/canbushack.com\/web\/wp-json\/wp\/v2\/media\/388"}],"wp:attachment":[{"href":"https:\/\/canbushack.com\/web\/wp-json\/wp\/v2\/media?parent=429"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/canbushack.com\/web\/wp-json\/wp\/v2\/categories?post=429"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/canbushack.com\/web\/wp-json\/wp\/v2\/tags?post=429"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
$01 \u2013 Request Current Powertrain Diagnostic Data
$02 \u2013 Request Powertrain Freeze Frame Data
$03 \u2013 Request Emission-Related Diagnostic Trouble Codes
$04 \u2013 Clear\/Reset Emission-Related Diagnostic Information
$05 \u2013 Request Oxygen Sensor Monitoring Test Results
$06 \u2013 Request On-Board Monitoring Test Results for Specific Monitored Systems
$07 \u2013 Request Emission-Related Diagnostic Trouble Codes Detected During Current or Last Completed Driving Cycle
$08 \u2013 Request Control of On-Board System, Test or Component
$09 \u2013 Request Vehicle Information
$0A \u2013 Request Emission-Related Diagnostic Trouble Codes with Permanent Status<\/p>\n\n\n\n
$10 \u2013 Initiate Diagnostics
$12 \u2013 Read Failure Record
$1A \u2013 Read Diagnostic ID (DID)
$20 \u2013 Return To Normal
$22 \u2013 Read Data By Parameter ID (PID)
$23 \u2013 Read Memory Address
$27 \u2013 Security Access
$28 \u2013 Disable Normal Communications
$2C \u2013 Define Dynamic Data Packet ID (DPID)
$2D \u2013 Define PID by Memory Address
$34 \u2013 Request Download
$36 \u2013 Transfer Data
$3B \u2013 Write DID
$3E \u2013 Tester Present
$A2 \u2013 Report Programming State
$A5 \u2013 Enter Programming Mode
$A9 \u2013 Check Codes
$AA \u2013 Read DPID
$AE \u2013 Device Control<\/p>\n\n\n\n
$7E0 03 22 00 0D 00 00 00 00<\/p>\n\n\n\n
$7E8 04 62 00 0D 01 7E 00 00<\/p>\n\n\n\n
$10 \u2013 Diagnostic Session Control
$11 \u2013 ECU Reset
$14 \u2013 Clear Diagnostic Information
$19 \u2013 Read Diagnostic Trouble Codes (DTC)
$22 \u2013 Read Data by ID
$23 \u2013 Read Memory by Address
$24 \u2013 Read Scaling Data by ID
$27 \u2013 Security Access
$28 \u2013 Communications Control
$2A \u2013 Read Data by Periodic ID
$2C \u2013 Dynamically Define Data ID
$2E \u2013 Write Data by ID
$2F \u2013 Input\/Output Control
$31 \u2013 Routine Control
$34 \u2013 Request Download
$35 \u2013 Request Upload
$36 \u2013 Transfer Data
$37 \u2013 Request Transfer Exit
$3D \u2013 Write Memory by Address
$3E \u2013 Tester Present
$83 \u2013 Access Timing Parameter
$84 \u2013 Secured Data Transmission
$85 \u2013 Control DTC Setting
$86 \u2013 Response on Event
$87 \u2013 Link Control<\/p>\n\n\n\n