Introduction to On Board Diagnostics (II)

Fundamentals of PowertrainControl strategies & OBD IIDiagnosticsGeneral Circuit Malfunction: This is a general purpose failure resulting in the componentnot responding with expected value or any value. This could be due to short circuit in thecircuit wiring, or an open circuit, or a complete break down of the function resulting ina wrong response including no response.Range/Performance: This is the case when the component is functional in general termsexcept that the response value is not within the normal operating range. This can be due tostuck at 0 or stuck at 1 fault, or erratic, intermittent, or skewed values indicating poorperformance of the circuit, component, or system.Low Circuit Input: The circuit voltage, frequency or other signal measured at the controlmodule input terminal or Pin is at or near zero. This is measured with the external circuit,component, or system connected. The signal type (voltage, frequency) shall be included inthe message in place of the word “input”.