Colt L4-1597cc 1.6L SOHC Turbo VIN F FI (1988)
Engine Speed Sensor: Description and Operation
The voltage of the negative terminal on the ignition coil makes sudden increases twice per engine revolution and is synchronized with the ignition
timing. By sensing this voltage change and measuring the time between peak voltages, the ECU computes engine speed, judges engine operating mode
and controls the air/fuel ratio and idle speed.
