This paper presents the electrical and thermal modeling of an Integrated Drive Unit (IDU) in a production electric SUV (GAC Aion LX). The IDU consists of a permanent magnet synchronous motor (PMSM), an inverter and a transmission gear box, and is cooled by circulating coolant through inverter and PMSM. Three IDU motor models were developed: Lumped Parameter Model, Saturated PMSM Model, and Efficiency-Map Model. Heat generation of the motor components, obtained from electromagnetic FEA simulation, was used as input to a transient Lumped Parameter Thermal Network (LPTN) model of the IDU. The IDU models were developed using MATLAB/ Simulink/ Simscape. The performance and inner temperature field of the IDU can be predicted real-time at various drive conditions, crucial for IDU design optimization and real-time temperature prediction.