Transmission control module (TCM) diagnostic functions: General

WARNING: This page is about a different car, the 2004 Volvo S40, 2003 Volvo S40, 2002 Volvo S40, 2001 Volvo S40, and 2000 Volvo S40. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Installing Hoist

Courtesy of VOLVO CARS OF NORTH AMERICA.

The control module has a built-in diagnostic system, the Volvo on-board diagnostic (OBD) system. This system continuously monitors its own system and the input and output signals.