Auto Stop/Start No Longer Available on Certain 2021 Models

The Automatic Stop/Start feature (Fig. 5) is no longer available on some 2021 model year vehicles due to the industry-wide shortage of semiconductors. The affected models include 2021 Silverado 1500, Tahoe, Suburban, Sierra 1500, Yukon and Escalade models equipped with 5.3L V8 (RPO L84) and 6.2L V8 (RPO L87) engines mated to the 10L80 10-speed automatic transmission (RPO MQB, MQC). The change removing the Automatic Stop/Start feature went into production on June 7, 2021.


Fig. 5


Affected vehicles produced on or after June 7, 2021 will have the added RPO NSS (Not Equipped with Automatic Stop/Start). RPO NSS will be used to identify vehicles built without Automatic Stop/Start. The Auto Stop button (Fig. 6) on the instrument panel also will be removed from the switch bank. These vehicles will receive revised EPA-certified fuel economy estimates.


Fig. 6


Any vehicle that includes RPO NSS is not equipped with Automatic Stop/Start technology, even if the vehicle also includes RPO KL9 (Engine Control – Stop/Start System), which is retained based on other components that remain on the vehicle.

These production changes regarding the availability of Automatic Stop/Start are currently expected to remain in place for the remainder of the 2021 model year.


– Thanks to David MacGillis and Hassan Abdallah

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