NOTE Distributorless ignition system may also be referred to as Electronic Spark Advance ESA system

Avalon, Highlander 3.0L V6 & Sienna

Distributorless Ignition System (DIS) uses Engine Control Module (ECM) for determining ignition timing (spark advance). 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Conventional distributor and pick-up coil have been replaced by 2 Camshaft Position (CMP) sensors and Crankshaft Position (CKP) sensor. CMP sensors may also be referred to as Variable Valve Timing (VVT) sensors. CMP sensors and CKP sensor deliver input signals to ECM. ECM detects standard crankshaft position based on input signals from CMP sensors and actual crankshaft position, and engine speed by crankshaft position sensor input signals. CMP sensors are located at flywheel end of each cylinder head, just below valve cover. See Fig. 9 , Fig. 17 and Fig. 23 . CKP sensor is located at front of crankshaft, near crankshaft pulley. See Fig. 9 , Fig. 17 and Fig. 23 . For Knock Sensor (KS) location, see REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.

The ECM uses 6 ignition primary control signals to the ignitors for the ignition coils. DIS uses 6 ignition coils with internal ignitors, one ignition coil for each cylinder. See Fig. 55 . Cylinder No. 1 is front cylinder on right side of engine when viewed from flywheel end of engine. Cylinder No. 2 is front cylinder on left side of engine when viewed from flywheel end of engine. Cylinders No. 1, 3 and 5 are on right side of engine. Cylinders No. 2, 4 and 6 are on left side of engine. ECM monitors IGF circuit at ignitor to ensure ignition coils have fired.

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