Upshift Indicator
WARNING: This page is about a different car, the 2007 Pontiac G5 Pursuit, 2007 Pontiac G5, and 2007 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
The Upshift indicator notifies the driver when to shift the transmission. The instrument panel cluster (IPC) illuminates the Upshift indicator as determined by the powertrain control module (PCM)/engine control module (ECM). The IPC receives a GMLAN serial data message from the body control module (BCM) requesting illumination of the indicator.