System for diagnosing an internal combustion engine

Patent · Tue May 20 04:00:00 EDT 1986

OSTI ID:5635631

Takahashi, T

A system is described for diagnosing an internal combustion engine having a starter and a starter switch effective to produce a starter signal dependent on the operation of the starter switch, and first means for generating an engine speed signal dependent on engine speed. The improvement described here consists of: a first comparator responsive to the engine speed signal for detecting the engine speed during cranking of the engine and producing a cranking signal; starter operation diagnosing circuit means responsive to the starter signal of the starter switch for producing a failure output when an absence of the starter signal during a presence of the cranking signal continues for a predetermined period; a second comparator for producing an engine operating signal when the engine speed signal exceeds idling speed; a terminal for grounding a circuit and for producing a grounding signal during the grounding; first gate means responsive to the engine operating signal of the second comparator and to the grounding signal for producing a first signal having a first logic level during the presence of the grounding signal and a second signal having a different, second logic level during the absence of the grounding signal and during the presence of the engine operating signal; second means responsive to the second signal having the second logic level for producing a third signal; second gate means for providing a fourth signal upon occurrence of the failure output of the starter operation diagnosing circuit means and the first signal having the first logic level and respectively the second signal; and warning means operated by the fourth signal from the second gate means.

• Assignee: Fuji Jukogyo Kabushiki Kaisha, Tokyo
• Patent Number(s): US 4590566
• OSTI ID: 5635631
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
COMPARATOR CIRCUITS
CONTROL EQUIPMENT
DIAGNOSTIC TECHNIQUES
ELECTRIC GROUNDS
ELECTRICAL EQUIPMENT
ELECTRONIC CIRCUITS
ENGINES
EQUIPMENT
FAILURES
HEAT ENGINES
IGNITION SYSTEMS
INTERNAL COMBUSTION ENGINES
SIGNALS
SPEED REGULATORS
SWITCHES
VELOCITY