A method of detecting faults in an air intake heating system for supplying heated air to a vehicle internal combustion engine, and an air intake heating and diagnostic system for use with a vehicle having an internal combustion engine

• Main Authors: ANDREWS, ERIC B, STEPPER, MARK, R
• Format: Patent
• Language: English; French; German
• Published: 22.12.1999
• Edition: 6
• Subjects: BLASTING; CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TOTRANSPORTATION; COMBUSTION ENGINES; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MECHANICAL ENGINEERING; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDEDFOR; STARTING OF COMBUSTION ENGINES; SUPPLYING COMBUSTION ENGINES IN GENERAL, WITH COMBUSTIBLEMIXTURES OR CONSTITUENTS THEREOF; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; WEAPONS

An air intake heating and diagnostic system (10) for an internal combustion engine includes a microprocessor based controller (12) for activating electrical heating elements (26 and 28) for a preheat time period prior to starting the engine and for a postheat time period after starting the engine. The controller (12) receives inputs corresponding to intake manifold air temperature, battery temperature, vehicle speed, engine speed, and key switch position. The system (10) continuously monitors the integrity of the various sensors (14,16,18,20), monitors the functionality of the heating elements (26 and 28) during the postheat time period, and warns the vehicle operator by illuminating a "check engine" lamp (38) if certain fault conditions are detected. In both cases, the controller (12) sets fault flags within the controller memory (40) corresponding to the detected fault conditions.