Ignition Timing Control

Programmed ignition used in this engine provides optimum control of ignition timing. The ECM determines the timing in response to engine speed and manifold vacuum pressure. The input signals are transmitted by the CYP/CKP sensor, TP sensor, radiator fan control sensor, and MAP sensor. This system is capable of setting lead angles with complicated characteristics that cannot be provided by conventional governors or diaphragms. See Fig 1 and Fig 2 . See COMPENSATION OF IGNITION TIMING table.

Fig 1: Locating Ignition System Components

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 2: ECM Timing Adjustment Input/Output Chart

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Compensation Of Ignition Timing

Compensation Item	Related Sensor Information	Description
Idling	CKP/CYP Sensor, MAP Sensor	Ignition Timing Is Controlled To The Target Speed With Compensation According To The Idling Speed
Compensation At Warmup	Engine Coolant Temperature (ECT) Sensor	Lag Angle Is Adjusted According To Warm-Up Conditions To Bring About A Good Balance Between Operating Performance And Exhaust Gas Level
Engine Coolant Temperature Compensation	ECT Sensor	Compensation For Lead Angle At Low Coolant Temperature And Lag Angel At High Coolant Temperature