Park Avenue Ultra V6-3.8L SC VIN 1 (1991)
Knock Sensor: Description and Operation
The knock sensor, installed in the engine block, signals the ESC module when an engine knock occurs. The ESC module then sends a signal to the PCM
which retards ignition timing. When the knocking stops, the PCM advances timing in small increments back to its preset value. This allows the PCM to
maintain maximum ignition timing advance for better fuel economy and performance under all operating conditions.