DTC P0326: Knock Sensor Module Circuit: Description

The knock sensor (KS) produces an AC voltage at all engine speeds and loads. The Powertrain Control Module (PCM) then adjusts the spark timing based on the amplitude and frequency of the KS signal. The PCM uses the KS signal to calculate the average voltage. Then the PCM assigns a voltage value. The PCM checks the knock sensor and related wiring by comparing the actual knock signal to the assigned voltage range. A normal KS signal should stay outside the assigned voltage range. This Diagnostic Trouble Code (DTC) will set if the PCM malfunctions in a manner that will not allow proper diagnosis of the KS system. The KS system uses 2 knock sensors. Both sensors are connected directly to the PCM using the following circuits:

• The KS 1 signal circuit.
• The KS 1 low reference circuit.
• The KS 2 signal circuit.
• The KS 2 low reference circuit.

KS 1 is at the front of the engine, or nearest the accessory belt. KS 2 is at the rear of the engine, or nearest the driveplate. Both sensors are on the intake side of the block.