Pickup 2WD L4-2254cc 2.3L SOHC (4ZD1) MFI (1994)
Ignition Control Module: Description and Operation
The power transistor, in-line between the ignition coil and ECM, is the switch that triggers the coil. By calculating various inputs, the ECM
controls ignition timing through its control of the power transistor. The ECM considers input from the crank angle sensor, throttle valve switch,
coolant temperature sensor, air flow sensor and vehicle speed sensor when calculating ignition timing.