Engine Controls - Tests W/Codes - BCM: Description

Toronado and Trofeo models use several electronic components which can be controlled by the service technician to provide valuable self-diagnostic information. The components are part of an electrical network designed to control various engine and body subsystems. This article will provide a description of the overall electronic network and the on-board diagnostic capabilities which have been designed to aid the service technician in system diagnosing and testing.

At the heart of the computer system is the Body Control Module (BCM). The BCM is located behind the glove box and has an integral microprocessor, which is the center for communication with all other components in the system. All sensors and switches are monitored by the BCM or by one of the following major components:

• Cathode Ray Tube Control (CRTC) (optional equipment)
• Electronic Control Module (ECM)
• Electronic Heater and A/C Control Panel (ECCP)
• Instrument Panel Cluster (IPC)
• Programmer-Heating and A/C (HVAC)
• SIR Diagnostic Energy Reserve Module (DERM) controller

The Cathode Ray Tube (CRT) is a touch sensitive color "monitor" located in the climate control/radio center for setting temperature controls and accessing BCM diagnostic features. Non-CRT equipped units have an Electronic Climate Control Panel (ECCP) with LED digital display area for temperature and override mode values. Both CRT and ECCP are used to access BCM diagnostics and display them in the IPC information center's 20 character LED display bar.