Geely EC718 2009 Workshop Manual page 100

2-18 Control System JL4G18-D
12. Defrost Heating Enable Input
The signal is provided by the BCM through a dedicated circuit
and is a voltage signal. The rear defrosting heating block is
essentially a resistance wire with fairly high heating power. The
power consumption is relatively high. When the rear defrost
heating starts, the generator load increases, causing the
engine speed fluctuate. In order to make the engine run
smoother, after ECM receives the signal, it increase the
engine's torque output. Switching signals pass through ECM
harness connector EN01 terminal No.24 to ECM. when the
signal fails, ECM does not record the relevant DTC code.
13. CAN Information Input
ECM downloads signals via CAN from the network for its own
needs. The most typical signals are: brake switch signal, ABS's
work status. CAN_HI signal circuit connects to other CAN
network modules through ECM harness connector EN01
terminal No.33. CAN_LO signal circuit connects to other CAN
network modules through ECM harness connector EN01
terminal No.34. If ECM fails to communicate with other
modules, it will record DTC code U0001, U0121, U0140,
U0151, P1523.
14. Serial Data Bus Input
When the ignition switch is turned on, the Anti-theft ignition coil
identifies whether the inserted key is an illegal key. The signal
is transmitted by the security module to ECM. ECM determines
whether to activate the engine Anti-theft locking system based
on this signal, such as cutting off the ignition, fuel injection, start
the circuit. ECM harness connector EN01 terminals No.15,23
are for serial data communication. The immobilizer system-
related failures DTC codes are P1610, P1611, P1612, P1613,
P1614.
EC718/EC718RV EC715/EC715RV 10/2009
2.2.2.3 Output Components
1. Idle Speed Control Valve (IAC)
Note
A. Do not to push and pull IAC valve core shaft, otherwise
it will damage the internal valve components.
B. When washing the IAC valve carbon residue, do not
let any cleaning agent enter the IAC valve inside,
otherwise it will damage IAC valve.
IAC valve is installed on the throttle body. ECM controls the
spool extended the amount to control the idle speed. Engine
sends the control module voltage pulses to the IAC valve motor
windings, so that IAC valve core shaft moves to the inside or
outside a certain distance (step or a count) with each pulse.
Shaft movement controls the air flow amount bypass the
throttle, and then controls the engine idle speed. The expected
idle speeds of all engine running conditions are programmed
and set in the ECM calibration program. These settings
includes engine speed based on engine coolant temperature,
speed, battery voltage, and Air-Conditioning system pressure.
Engine control module reads the correct IAC valve position to
meet the expectations of stable, warm-up idle speed under
different conditions. This information is stored in the engine
read-only memory, even after the ignition switch is switched off,
the information will not be cleared. If the engine control module
power supply is disconnect, it will lead to an incorrect idle speed
control. When starting, press the accelerator pedal half way
until the engine control module learns idle speed control. ECM
controls IAC valve through ECM harness connector EN01
terminals No.21,22,35,36. If the idle speed control valve
position does not match the actual ECM required location, DTC
code P0506, P0507 will be recorded. If idle speed control valve
circuit has a malfunction, DTC code P0508, P0509, P0511 will
be recorded.
Engine
FE02-5130b