Circuit/System Description

WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.

The T19 Multifunction Power Supply Converter is supplied voltage through B+ circuit 6240 and B+ circuit 6340. Ground is provided by ground circuit 2550, of which there are two redundant circuits. The T19 Multifunction Power Supply Converter is used to maintain constant battery voltage to necessary components during an auto engine stop/start event. At the T19 Multifunction Power Supply Converter, the B+ circuit 6240 provides voltage to control circuit 2172 and the B+ circuit 6340 provides voltage to control circuit 2173. The K20 Engine Control Module commands the KR27 Starter Relay by providing voltage on the control circuit 625. The T19 Multifunction Power Supply Converter monitors control circuit 625 as an indicator that the K20 Engine Control Module has commanded the engine to start, ending the auto engine stop/start event. During the engine start, the T19 Multifunction Power Supply Converter will supply voltage on control circuit 2172 and control circuit 2173, which provides critical components and control module a stable voltage during the engine start event.

The T19 Multifunction Power Supply Converter communicates voltage on control circuit 2172 and control circuit 2173 to the K20 Engine Control Module on the powertrain CAN bus. The K20 Engine Control Module compares voltage on ignition circuit 439 voltage to the indicated voltage received from the T19 Multifunction Power Supply Converter to determine if there is a system fault.

The S86 Vehicle Stability Control System Switch incorporates the auto stop/start disable switch which will disable the auto stop/start system when the switch is pressed and released, the system will be enabled again if the switch is pressed and released or the ignition is cycled off and back on. The auto stop/start disable switch is a hard wired to the K9 Body Control Module. When the switch is pressed the signal circuit 1111 is grounded though the switch ground circuit 1450, when the auto stop/start system is disabled the K9 Body Control Module circuit 1110 sends a pulse with modulated voltage to illuminate the indicator, the indicator is grounded through the switch by ground circuit 1450.