Flash: Hybrid Control Processor (HCP) and Auxiliary Hybrid Control Processor (AHCP) Updates Customers may...

Bulletin number

08-031-23

Component

Power train

Summary

Flash: Hybrid Control Processor (HCP) and Auxiliary Hybrid Control Processor (AHCP) Updates Customers may experience one or more of the following: ?Service Charging System? popup when keying the vehicle to off while still in drive. Engine must be started twice to achieve drive ready (at low temperatures around -30°C, -22°F) when the vehicle was entered and started quickly. Radiator fan cycling while in park and with vehicle operational. May be described as ?breathing? sound from the front of the vehicle. ?Performance Limited, Service Fuel System? popup while driving. Radiator fan spinning at max speed while charging. The vehicle is providing max cooling when the charging module reaches high temperature. May be described as a loud sound that disappears when the vehicle is unplugged. Poor cabin heat in electric mode. Temporary loss of cabin cooling (<5s) while driving in electric mode. SOC dropping lower than expected while in eSave Battery Charge mode. Turtle mode while re-fueling in hot ambient. Unable to enter electric mode driving while FORM is active. This bulletin involves reprogramming the HCP and AHCP or also known as Power Inverter Module (PIM) with the latest available software. NOTE: Additional module flashes are required for this update to be effective, the following modules are all to be updated along with this HCP and AHCP update: Powertrain Control Module (PCM). Transmission Control Module (TCM).

Owners of these vehicles have filed 19 complaints in the transmission category.