Chery A11 2003 Repair Manual page 313

Maintenance Manual for Chery·Windcloud
4. Knock Sensor KS
Purpose: this sensor is designed to provide
ECU with engine knocking information so as to
carry out knocking control.
Composition and principle: knock sensor is a
sort of vibration acceleration sensor, which is
fixed on engine cylinder block. ECU judges the
occurrence of engine knocking by using
vibration frequency signal outputed by knock
sensor, which goes through filtration.
Failure diagnosis: ECU monitors on various
sensors, actuators, power amplification circuits
and sensing circuits. In case any of the
following situations occurs, failure mark of the
knock sensor is set.
  K nock sensor failure
  K nocking control data processing circuit failure
  C ylinder-detecting signal is unreliable
After failure mark of knock sensor being set,
knocking closed-loop control is shut down,
reduceing a safety angle from the ignition
advance angle stored in ECU. When error
frequency cuts down to below setting value,
failure mark restores.
Installation hint:
20±5Nm.
tightening torque
MOTOROLA EFI System
Knock sensor with cable
Circuit diagram of knock sensor
Pins:
1 Knock sensor signal 1(ECU B2#)
2 Knock sensor signal 2 (ECU B3#)
Troubleshooting: mainly check if there is
short circuit or open circuit on the connection
is
between 2 lines on senosr and corresponding
ECU pins.
If gasket is added during installation; if
tightening torque is proper.
If there is stitching defect between sensor and
cylinder, or if there is foreign matter between
them.
1. Knocking block
2. Casing
3. Piezoelectric ceramics
4. Contactor
5. Electric connection
Knock sensor
4