Engine ID Needed during ECM Programming

While programming an Engine Control Module (ECM) on some 4-cylinder engines, the Service Programming System (SPS) may prompt for an engine identification number. (Fig. 15) The engine ID number is used to track engine calibrations.

Fig. 15

Engine IDs may be requested when programming ECMs on the following models and engine RPOs:

Model Engine RPO
2013-2019 ATS 2.0L (LTG), 2.5L (LCV, LKW))
2013-2019 Malibu 2.0L (LTG), 2.5L (LCV, LKW)
2014-2019 CTS, XTS 2.0L (LTG)
2014-2019 Impala, Regal 2.0L (LTG), 2.5L (LCV, LKW)
2015-2019 Colorado, Canyon 2.5L (LCV)
2015-2019 Envision 2.0L (LTG), 2.5L (LCV)
2016-2018 CT6 2.0L (LTG)
2017-2019 XT5 2.0L (LTG)
2017-2019 LaCrosse 2.0L (LTG)
2017-2019 Acadia 2.5L (LCV)
2018-2019 Traverse 2.0L (LTG), 2.5L (LCV, LKW)
2018-2019 Equinox, Terrain 2.0L (LTG)
2019 Blazer 2.0L (LTG)


The engine ID number is found on the engine tag, which is typically located on the front timing cover or the side of the engine block near the oil pan. For engine tag location on a specific vehicle, check the appropriate Service Information under General Information > General Information > Introduction > Vehicle, Engine and Transmission ID and VIN Location, Derivative and Usage. (Fig. 16)

Fig. 16

The engine ID is circled in the following photo. (Fig. 17) When entering the ID from the tag, do not enter any spaces if they exist in the identification number.

Fig. 17

– Thanks to Norman Grayson

Measuring Voltage Drop and Resistance
Low Voltage or Loss of Power/Ground during ECM Diagnosis


  1. what can a person do if the engine lable is missing?

  2. What happens when the ID tag is missing or can’t be read due to age and wear?

  3. Be sure to compare both labels found on block and front cover. Some replacement engines are / were sent with a FWD cover and needed to be swapped with RWD applications. Sometimes I have found the old engine serial label left in place. When I was replacing them I usually removed the old label from the cover to help avoid confusion later.

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