P1326 Fault Code

Long Description

Fault code P1326 is a manufacturer-specific fault code that is logged when the car’s primary computer, the powertrain control module (PCM), has detected an issue with the knock sensor circuit for cylinder 2 of the engine.

This code is specific to Audi and Volkswagen vehicles.

This code occurs when the signal received from the knock sensor is too low, which can mean the knock sensor or its circuit are malfunctioning.

Knock sensors are installed in the engine to detect unwanted vibrations or pinging. These typically occur due to improper or incorrect combustion or other unbalancing forces. This is often referred to as spark knock.

Left unchecked, these knocks can seriously harm the engine. This makes it important to address the issue immediately.

Other Signs of This Problem

Because this fault code represents an issue with the knock sensor itself and not the presence of an actual knock, there may be little to no signs of the issue.

This means it becomes even more important to pay attention to the presence of the Check Engine light or Malfunction Indicator Lamp (MIL).

There may also be other fault codes logged that relate to the knock sensors. These can range from P0324 up to P0334.

In some cases, the vehicle may be suffering from lower fuel economy and performance.

What Could Be The Problem?

There may be several causes for this fault code to be logged. Most of these are related to the faulty knock sensor and its circuitry.

A faulty or damaged knock sensor will obviously be unable to provide the correct output signal to the PCM.

Water contamination in the knock sensor is also a possibility, particularly with Chevrolet engines according to various sources.

The wiring for the knock sensor can also cause this fault. Loose or damaged connections or wires can cause issues. Additionally, a short or open circuit can also cause this fault code.

In some rare cases, the PCM may be faulty. It is also possible for the PCM to be running on outdated software.

Fixes

The fixes for this issue should focus on the knock sensor itself and its corresponding circuitry.

The sensor itself should be tested. If it is faulty, it should be replaced.

The wiring and connections for the sensor should be checked. If there are any damaged or frayed wires or loose connections, these must be repaired. Additionally, the connections should be clean from contamination.

Ensure that there is no short or open circuit present in the sensor circuit.

If there are issues with the PCM software, an update could fix this. In rare instances, the PCM may need to be replaced. This will likely only be necessary for a situation where many other fault codes were simultaneously logged.

Seriousness

This issue should be considered serious. While fault code P1326 itself does not represent a serious issue, the PCM being unable to accurately detect a knock in the engine is a serious problem.

An undiagnosed knock in the engine can hugely degrade the service life of a variety of components. It is strongly recommended to have the knock sensor fixed immediately.