GS400, LS400 & SC400

Distributorless Ignition System (DIS) uses the Engine Control Module (ECM) for determining ignition timing (spark advance). The ECM may determine ignition timing (spark advance) based on various input signals, engine RPM and knock sensor input signals.

Conventional distributor and pick-up coil have been replaced by a camshaft position sensor and crankshaft position sensor. Camshaft position sensor and crankshaft position sensor deliver input signals to ECM. The ECM detects the standard crankshaft position based on camshaft position sensor input signals, and the actual crankshaft position and engine speed by the crankshaft position sensor input signals.

The ECM uses 8 ignition primary control signals to the ignitors for the ignition coils. The DIS uses 8 ignition coils with internal ignitors, one ignition coil for each cylinder. Cylinder No. 1 is front cylinder on left side of engine when viewed from flywheel end of engine. Cylinder No. 2 is front cylinder on right side of engine when viewed from flywheel end of engine. Cylinders No. 1, 3, 5 and 7 are on left side of engine. Cylinders No. 2, 4, 6 and 8 are on right side of engine.

The ECM monitors IGF circuit at the ignitor to ensure ignition coils have fired. The ECM stops fuel injection as a fail-safe function if IGF signal if ECM does not receive the IGF signal.