Circuit/System Description
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The PSCM monitors vehicle speed validity message from the engine control module (ECM) via the serial data circuit. The power steering control module (PSCM) uses this vehicle speed message, along with the torque sensor and motor rotational sensor inputs, to determine the desired amount of steering assist.
The PSCM monitors the intermediate voltage power limit request message from the accessory power module (APM) to detect a possible overheating event. The hybrid control module (HCM) sends this message to the PSCM via the serial data gateway module to reduce the APM power output to the PSCM until the APM returns to normal operating temperature.