Chrysler laser 1990 Technical Information Manual page 137

Terminal for
ignition timing
adjustment
7
elements
Detonation
sensor
FUEL SYSTEM - Sensors
IGNITION TlMlNG ADJUSTMENT TERMINAL
This terminal is used when adjusting the basic ignition timing or
basic idle speed.
When this terminal is shorted to ground, the engine control unit
cancels the
sets the ignition
adjusting mode.
For the basic idle speed adjustment, the diagnosis terminal is
DETONATION SENSOR <Turbo>
The detonation sensor is installed at a position where it can
detect, with a high degree of precision, knocking generated at
each cylinder; it detects cylinder block vibrations caused by
knocking, and outputs voltage proportional to the magnitude of
those vibrations.
Because cylinder block vibrations caused by knocking vary
from engine to engine, the engine control unit passes this
through a frequncy filter, detecting only the knocking, thus
resulting in a spark retardation of the ignition timing that
corresponds to the strength of the knocking.
Engine control
unit
and idle speed control servos in their