Gm Global Technolgoy Operations, Inc.

Michael Chernyak

William Leonard Aldrich, Iii

Xuefeng Tim Tao

Keith D Van Maanen

Brian M Porto

Craig J Hawkins

Parsa Mahmoudieh

Steven A Tarnowsky

Donald D Crites

Brian James Pellerito

Roger Joseph Rademacher

Cheol W Kim

Michael E Polom

Zhenhu Zhuang

Emmanuel V Yabes

A powertrain system including an engine and transmission is described, and includes a temperature sensor disposed to monitor a hydraulic fluid for the transmission. A method for monitoring the temperature sensor includes monitoring engine operation including engine coolant temperature and monitoring a signal output from the temperature sensor. An indicated temperature slope is determined based upon the signal output from the temperature sensor, and a temperature region associated with the engine coolant temperature is determined. Performance of the temperature sensor is evaluated based upon the indicated temperature slope and minimum and maximum temperature slope thresholds that are associated with the temperature region.

Method and apparatus to monitor a temperature sensor

A method of controlling a vehicle includes signaling a transmission to shift into a first gear ratio and sensing a current gear ratio of the transmission after signaling the transmission to shift into the first gear ratio. The method further includes implementing a diagnostic transmission shift control strategy to override a normal transmission shift control strategy when the current sensed gear ratio is not equal to the requested first gear ratio to verify proper functionality of a mode control valve that is responsible for shifting the transmission into the first gear ratio.

Method of controlling a vehicle during an auxiliary pump failure

A system includes an auxiliary pump that provides pressurized fluid to a transmission during an engine auto stop/start event. A mechanical pump provides pressurized fluid to a transmission during engine operation after the engine auto stop/start event. An auxiliary pump diagnostic system includes a slip determination module that determines slip of a torque converter based on an engine speed and a transmission input speed. A fault determination module diagnoses a fault in the auxiliary pump in response to an engine auto start and based on the slip of the torque converter.

Auxiliary pump diagnostic systems and methods

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Farmington Hills, MI, United States of America

Michael Chernyak