Probe L4-133 2.2L SOHC Turbo (1989)
Electronic Spark Control Module: Description and Operation
When vibration in the engine occurs, voltage is generated by the knock sensor and a signal is sent to the knock control unit. The knock control unit
determines whether the signal from the knock sensor is pre-ignition of vibration. A signal is sent to the electronic control assembly and spark timing is
retarded to the intensity of the knock. The knock control unit is mounted on the firewall next to the barometric pressure sensor.