On-Board Diagnostics: Notes

A diagnostic readout box (C-4805 ) is used to recall stored codes. The readout tool can be used to check three different system modes. These are: Diagnostic Test Mode, Circuit Actuation Test Mode (ATM test), and Switch Test Mode.

The Diagnostic Test Mode is used to retrieve fault codes that may be stored in the computer; the Circuit Actuation Test Mode (ATM Test) is used to check out specific component systems; the Switch Test Mode is used to check certain switch circuits.