Test Description

WARNING: This page is about a different car, the 1995 Oldsmobile Ninety-Eight and 1995 Buick Park Avenue. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Test numbers refer to numbers on diagnostic chart.

If Code P0325 is detected, PCM will retard spark timing. If an audible knock is heard from engine, repair internal engine problem. Normally no knock should be detected at idle.
PCM applies 5 volts through a pull-up resistor which should be present at knock sensor terminal.
Determines if knock sensor is faulty or if knock sensor portion of PROM is faulty.

Fig 1: Code P0325 Schematic (3.8L) Knock Sensor Error (Single Sensor)

Fig 2: Code P0325 Diagnostic Flow Chart (3.8L) Knock Sensor Error (Single Sensor)