Motor vehicle diagnostic and monitoring device having keep alive memory

• Main Authors: KASTURA; JOHN L, STEWART; WILLIAM R
• Format: Patent
• Language: English
• Published: 02.06.1981
• Subjects: ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING ORSUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES INGENERAL; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDEDFOR ELSEWHERE; BLASTING; CHECKING-DEVICES; COMBUSTION ENGINES; COMBUSTION ENGINES IN GENERAL; GENERATING RANDOM NUMBERS; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; INTERNAL-COMBUSTION PISTON ENGINES; LIGHTING; MEASURING; MECHANICAL ENGINEERING; PERFORMING OPERATIONS; PHYSICS; REGISTERING OR INDICATING THE WORKING OF MACHINES; TESTING; TESTING STATIC OR DYNAMIC BALANCE OF MACHINES ORSTRUCTURES; TESTING STRUCTURES OR APPARATUS NOT OTHERWISE PROVIDED FOR; TIME OR ATTENDANCE REGISTERS; TRANSPORTING; VEHICLES IN GENERAL; VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISEPROVIDED FOR; VOTING OR LOTTERY APPARATUS; WEAPONS

A diagnostic and warning system for a motor vehicle monitors the condition of a number of preselected parameters. When the condition of the parameters is representative of a fault condition, the system energizes a malfunction light in the vehicle compartment during the period of the detected fault. The particular fault detected is stored in a nonvolatile memory where it is stored independent of the subsequent condition of the respective parameter. The stored fault conditions may thereafter be read from memory to provide an indication of the malfunctions that have occurred in response to a diagnostic interrogation signal. The fault conditions stored in the nonvolatile memory are erased when a predetermined time period has lapsed since the occurrence of a detected fault condition so that old nonrecurring self-correcting faults are not retained in memory and accordingly not indicated in response to a diagnostic interrogation signal.