Description of on-Board Diagnostics

ON-BOARD DIAGNOSTICS SYSTEM OPERATION

Electronic Climate Control (ECC) Panel:

This vehicle is equipped with an extensive on-board diagnostic system which is capable of detecting and compensating for faults, alerting the operator of a fault and recording pertinent data during the failure. It is also capable of displaying information about current vehicle performance when a fault occurred.

In order to access and control the self diagnostics features available, additional electronic components are utilized by the service technician. The Electronic Climate Control (ECC) and the Fuel Data Center (FDC) provide displays and keyboard switches.

The display and keyboard information is transmitted over a single wire data circuit which carries the coded data messages back and forth between the different control computers. and the display panels (ECC/FDC). This communications process allows the appropriate computer to transfer any of its available diagnostic information to the appropriate panel for display during service. By depressing appropriate buttons on the ECC, data messages are requested to be displayed on the FDC. the diagnostics mode, the mode indicators on the Electronic Climate Control (ECC) are used to indicate system operating modes. The different modes of operation are indicated by the status indicator either being turned "ON" or turned "OFF".