Camry XLE Sedan L4-2164cc 2.2L DOHC (5S-FE) MFI (1999)
Engine Control Module: Description and Operation
DESCRIPTION
The Engine Control Module (ECM) controls all phases of electrical engine operation. In order to accomplish this control, the ECM relies on the input
from a variety of engine operation sensors.
The ECM compares input signals with those stored in memory to determine what steps should be taken to achieve maximum performance, fuel economy,
and meet emission standards. The ECM outputs the necessary signals to the fuel system, ignition system, emission control systems, etc..
Battery positive voltage is supplied to terminal BATT of the ECM even when the ignition switch is OFF for use by the DTC memory and air-fuel ratio
adaptive control value memory, etc.