Editing Electronic control unit (section)

{{Short description|Automotive control system}}
{{About|controls for motor vehicles||Control unit (disambiguation)}}
[[File:2008-04-17 ECU.jpg|thumb|right|An ECU from a [[Geo Storm]]]]

An '''electronic control unit''' ('''ECU'''), also known as an '''electronic control module''' ('''ECM'''), is an [[embedded system]] in [[automotive electronics]] that controls one or more of the [[Automotive electronics#Types|electrical systems]] or subsystems in a car or other [[motor vehicle]].

Modern vehicles have many ECUs, and these can include some or all of the following: [[Engine control unit|engine control module]] (ECM), [[powertrain control module]] (PCM), transmission control module (TCM), brake control module (BCM or EBCM), central control module (CCM), central timing module (CTM), general electronic module (GEM), [[body control module]] (BCM), and suspension control module (SCM). These ECUs together are sometimes referred to collectively as '''the car's computer''' though technically they are all separate computers, not a single one. Sometimes an assembly incorporates several individual control modules (a PCM often controls both the engine and the transmission).<ref name="NIwhite">[http://www.ni.com/white-paper/3312/en/ National Instruments White Paper on Electronic Control Units] {{webarchive|url=https://web.archive.org/web/20131221083019/http://www.ni.com/white-paper/3312/en/ |date=2013-12-21 }}</ref>

Some modern motor vehicles have up to 150 ECUs.<ref>{{Cite web|date=2019-05-15|title=Number of automotive ECUs continues to rise|url=https://www.eenewsautomotive.com/news/number-automotive-ecus-continues-rise|access-date=2021-07-18|website=eeNews Automotive|language=en}}</ref> [[Embedded software]] in ECUs continues to increase in line count, complexity, and sophistication.<ref>{{cite journal|title=Embedded Software: Facts, Figures, and Future | journal=Computer| volume=42| issue=4| pages=42–52| last1=Ebert| first1=Christof| last2=Jones| first2=Capers| date=2009-04-01 | url=http://portal.acm.org/citation.cfm?id=1550393.1550433 | access-date=2010-09-15| doi=10.1109/MC.2009.118| s2cid=14008049| url-access=subscription}}</ref> Managing the increasing complexity and number of ECUs in a vehicle has become a key challenge for [[original equipment manufacturer#Automotive parts|original equipment manufacturers]] (OEMs).