DTC P0326 Knock Sensor CKT Excessive Spark Retard. Cadillac Eldorado 2000

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2000 🢒 Eldorado 🢒 Engine 🢒 Engine Controls - 4.6L 🢒 DTC P0326 Knock Sensor CKT Excessive Spark Retard

Engine Controls Component Views
Ignition Control Module - Rear Bank
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The powertrain control module (PCM) uses a knock sensor (KS) to detect engine detonation (spark knock). The knock sensor produces an AC signal at all engine speeds, and loads. The PCM makes adjustments to the spark timing based on the amplitude and frequency of the KS signal.

The PCM uses the KS signal to learn the average level of engine noise (noise channel). The PCM checks the KS system by comparing the actual KS signal to the noise channel. A normal KS signal should switch outside a voltage range above and below the noise channel. When the PCM detects a knock, the PCM will retard the spark timing until the knock goes away. If the knock is such that the vehicle operates on large amounts of spark retard, and the PCM is unable to eliminate the knock, DTC P0326 will set.

Conditions for Running the DTC

•	Engine speed is more than 600 RPM.

•	The knock detection is enabled.

Conditions for Setting the DTC

•	The KS signal indicates an engine knock is present.

•	The PCM commanded spark retard at a given engine load and speed is more than the calibrated value.

•	The condition is present for at least 3.5 seconds.

Action Taken When the DTC Sets

•	The PCM will not illuminate the malfunction indicator lamp (MIL).

•	The PCM will store the conditions present when the DTC set as Fail Records data.

Conditions for Clearing the MIL/DTC

•	The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

•	The DTC can be cleared using the scan tool Clear DTC Information function.

Diagnostic Aids

If the conditions is intermittent, refer to Intermittent Conditions in Symptoms.

Step	Action	Values	Yes	No
1	Did you perform the Powertrain On Board Diagnostic (OBD) System Check?	--	Go to Step 2	Go to Powertrain On Board Diagnostic (OBD) System Check
2	Visually/Physically inspect for a loose vehicle accessory and/or accessory bracket. If the condition is found, repair as necessary. Did you find and correct the condition?	--	Go to Step 4	Go to Step 3
3	Start the engine. Check for excessive mechanical noise. Refer to Engine Noise Diagnosis in Engine Mechanical. If a condition is found, repair as necessary. Did you find and correct the condition?	--	Go to Step 4	Go to Detonation/Spark Knock
4	Review and record the scan tool Fail Records Data. Clear the DTCs. Operate the vehicle within the parameters listed in the Conditions for Running the DTC. Using the scan tool, monitor the Specific DTC Information for DTC P0326 until the test runs. Does the scan tool indicate that DTC P0326 passed?	--	System OK	Go to Step 2