E.C.C. Trouble Diagnoses (Models with catalyzer without E.G.R.) — Diagnostic Procedure 3 (Cont'd)

INSPECTION START

CHECK OVERALL FUNCTION. 1) Start engine and warm it up sufficiently. 2) Run engine at about 2,500 rpm for about 5 minutes under no-load. 3) Keep engine speed at 2,000 rpm under no-load, make sure that green L.E.D. on E.C.U. goes on and off periodically more than 5 times during 10 seconds. — OR — 3) Keep engine speed at 2,000 rpm under no-load, check voltage between terminal 4 and terminal 1 on check connector. Needle of voltmeter should fluctuate between approximately 0V and battery voltage more than 5 times during 10 seconds.

CHECK HARNESS CONTINUITY BETWEEN E.C.U. AND CHECK CONNECTOR. 1) Stop engine. 2) Disconnect E.C.U. harness connector. 3) Check harness continuity between E.C.U. terminal 3 and terminal 4, terminal 1 and body ground. Continuity should exist.

CHECK INPUT SIGNAL CIRCUIT. 1) Disconnect exhaust gas sensor harness connector. 2) Check harness continuity between E.C.U. terminal 2 and terminal 2 (Harness side connector E68). Continuity should exist.

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