Supra Turbo
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 signal.
Conventional distributor and pick-up coil have been replaced by 2 camshaft position sensors and a crankshaft position sensor. Camshaft position sensors 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. Camshaft position sensors are located on intake manifold side of cylinder head. See Figure-16. Crankshaft position sensor is located near crankshaft pulley, just above oil pan on passenger's side of engine. See Figure-16. For knock sensor location, see REMOVE/INSTALL/OVERHAUL article.
The ECM uses 6 ignition primary control signals for the ignition coils. See Fig 1. The ECM monitors IGF circuit at the ignitor to ensure ignition coils have fired.