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Home >> Buick >> 2019 >> Envision Base >> Repair and Diagnosis >> External Pages >> Different car >> Section 21 (Image Display Camera System) >> Diagnostic Information and Procedures >> Rear Vision Camera System Malfunction (without UVH) >> Circuit/System Description

Circuit/System Description

WARNING: This page is about a different car, the 2018 Buick Envision. However, it is still accessible from the selected car via links, so may be relevant.

When the transmission is placed into R, a 12 V signal is sent to the Rearview Camera indicating that camera operation is requested. Ignition voltage and ground are supplied to the Rearview Camera. The Rearview Camera sends video image to the K188 Human Machine Interface Control Module Bypass Module through a video signal + and a video signal - circuit. The K188 Human Machine Interface Control Module Bypass Module passes the video image to K74 Human Machine Interface Control Module via video signal + and a video signal - circuits. The K188 Human Machine Interface Control Module Bypass Module is used to ensure the K74 Human Machine Interface Control Module produces a quality rear vision camera image to be displayed on the K48 Infotainment Faceplate Control Module when the vehicle is placed in reverse gear. In the event the K188 Human Machine Interface Control Module Bypass Module detects an issue with the camera image generated by the K74 Human Machine Interface Control Module, such as a black, solid color, frozen, or image other than the camera image, the K188 Human Machine Interface Control Module Bypass Module will assume control of the image to the K48 Infotainment Faceplate Control Module and displays a raw camera image with no park assist projection lines or object detection symbols for the entire reverse cycle.

The K188 Human Machine Interface Control Module Bypass Module is part of the video signal + and a video signal - circuits path from the B87 Rearview Camera to the K74 Human Machine Interface Control Module as well as the digital LVDS path (USB cable) between the K74 Human Machine Interface Control Module and K48 Infotainment Faceplate Control Module and needs to be active for either signal to be received by these modules. The K188 Human Machine Interface Control Module Bypass Module is not connected to serial data and uses the reverse lamp voltage input to determine the vehicle gear state.