1.8l. What are the probable causes of DTC P0325?

DTC P0325: Knock Sensor (KS) Circuit
P0325
The KS signal circuits are open or shorted together for 6 seconds.
probably need a new sensor

P0325 Knock Sensor 1 Circuit Malfunction
A knock sensor tells the engine computer when one or more of your engine's cylinders are "knocking", that is, exploding the air/fuel mixture in a way that delivers less power and can be damaging to the engine if prolonged.
The computer uses this information to tune the engine so that it doesn't knock. If your knock sensor wasn't operating properly, so that it was always indicating a knock, the engine computer's response may have been to change the ignition timing on your engine. Knock sensors generally bolt into or thread into the engine block. This P0325 code may show up intermittently or the Service Engine light may be lit constantly. Other knock sensor related DTC codes include P0330.
Symptoms You may notice drivability problems including a lack of power and perhaps some hesitation. There may also be other symptoms.
Causes A code P0325 most likely means one or more of the following has happened:

• The knock sensor is faulty and needs to be replaced
• There is a wiring short/fault in the knock sensor circuit

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CARB (California Air Resources Board) has a consistent policy regarding monitoring knock (Ks) sensors but vehicle manufacturers don't have a consistent way of using knock sensor circuitry. There are generally two methods that manufacturers have for using the knock sensor.
In the first design, which is found in most vehicles, the knock sensor plays an active role in controlling ignition timing. In this system, the PCM is advancing ignition timing until knock occurs and then retards timing slightly. This system runs on the verge of engine knock at all times. In this system the function of the knock sensor circuit is critical. If the sensor malfunctioned, precise ignition timing control could not be achieved.

A "dead" sensor circuit would not be able to detect actual knock, timing would be overly advanced, and NOX exhaust emissions would increase. For this reason, manufacturers that use the knock sensor in this manner are required to monitor this sensor and light the MIL light when a malfunction is detected.

In the second design, the knock sensor plays a very passive role and is really only on the engine for protection purposes. The various engine sensors send their information to the PCM to determine ignition timing. The PCM uses this information to control the ignition timing based on look-up tables stored in its memory. If ignition knock is detected, the PCM will take action and ****** the timing a few degrees. This type of control is generally used to control spark knock caused by changes in fuel octane.

Used in this way, the knock sensor is less critical to emissions and may not even have a measurable emission impact. Unlike the first design, a "dead" knock sensor in this system will have little to no effect on the operation of the engine. Manufacturers that use this design are not required to monitor the sensor under EPA OBDII regulations and will not turn on the MIL if the P0325 DTC is set.
Remember, this sensor does not change the operation of the engine. The customer will not notice any change in the way the vehicle operates. The knock sensor system has a one trip detection logic and WILL NOT turn on the MIL or store Freeze Frame data.

How to Diagnose P0325
Most technicians know how this type of sensor operates. Its element produces a voltage when the sensor picks up a vibration, usually caused by engine detonation.Technicians then check the ohmic value of the sensor.
Maybe this was of some help.Your valuable feedback would be appreciated.Thanks for choosing Fixya.

A knock sensor tells the engine computer when one or more of your engine's cylinders are "knocking", that is, exploding the air/fuel mixture in a way that delivers less power and can be damaging to the engine if prolonged. The computer uses this information to tune the engine so that it doesn't knock. If your knock sensor wasn't operating properly, so that it was always indicating a knock, the engine computer's response may have been to change the ignition timing on your engine. Knock sensors generally bolt into or thread into the engine block.

This P0325 code may show up intermittently or the Service Engine light may be lit constantly. Other knock sensor related DTC codes include P0330.

Symptoms: You may notice drivability problems including a lack of power and perhaps some hesitation. There may also be other symptoms.

Causes: A code P0325 most likely means one or more of the following has happened:
* The knock sensor is faulty and needs to be replaced
* There is a wiring short/fault in the knock sensor circuit

Possible Solutions
* Check the resistance of the knock sensor (compare it to factory specs)
* Check for broken/frayed wires leading to the sensor
* Replace the knock sensor


Test it and tell us news.

It does sound like the sensor may be bad, but you also need to check the wiring.
This information comes from:

http://www.obd-codes.com/p0325

P0325 OBD-II Trouble Code Technical Description

Knock Sensor Circuit Malfunction
What does that mean?

A knock sensor tells the engine computer when one or more of your engine's cylinders are "knocking", that is, exploding the air/fuel mixture in a way that delivers less power and can be damaging to the engine if prolonged. The computer uses this information to tune the engine so that it doesn't knock. If your knock sensor wasn't operating properly, so that it was always indicating a knock, the engine computer's response may have been to change the ignition timing on your engine. Knock sensors generally bolt into or thread into the engine block. This P0325 code may show up intermittently or the Service Engine light may be lit constantly. Other knock sensor related DTC codes include P0330.
FB.init("dd7d9e9681341cde77587bc6a2029f6f"); OBD-Codes.com on Facebook Symptoms

You may notice drivability problems including a lack of power and perhaps some hesitation. There may also be other symptoms.
Causes

A code P0325 most likely means one or more of the following has happened:

• The knock sensor is faulty and needs to be replaced
• There is a wiring short/fault in the knock sensor circuit

Possible Solutions

• Check the resistance of the knock sensor (compare it to factory specs)
• Check for broken/frayed wires leading to the sensor
• Replace the knock sensor

P0325 OBD-II Trouble Code

Technical Description: Knock Sensor Circuit Malfunction

What does that mean?A knock sensor tells the engine computer when one or more of your engine's cylinders are "knocking", that is, exploding the air/fuel mixture in a way that delivers less power and can be damaging to the engine if prolonged. The computer uses this information to tune the engine so that it doesn't knock. If your knock sensor wasn't operating properly, so that it was always indicating a knock, the engine computer's response may have been to change the ignition timing on your engine. Knock sensors generally bolt into or thread into the engine block. This P0325 code may show up intermittently or the Service Engine light may be lit constantly. Other knock sensor related DTC codes include P0330.

Hope this helps.

Your battery has nothing to do with these codes. Your vehicles computers have detected a malfunction or failure in the system. This triggers these codes and sets your check engine light. Below I have listed the code meanings and some repair solutions.

P1126 - Throttle Position (Narrow Range) Sensor Circuit Malfunction.

Power supply for the throttle control motor is provided to the ECM via throttle control motor relay. The throttle control motor relay is ON/OFF controlled by the ECM. When the ignition switch is turned ON, the ECM sends an ON signal to throttle control motor relay and battery voltage is provided to the ECM. When the ignition switch is turned OFF, the ECM sends an OFF signal to throttle control motor relay and battery voltage is not provided to the ECM.

Possible Causes For P1126:
- Harness or connectors (Throttle control motor relay circuit is open)
- Throttle control motor relay


P0325 - Knock Sensor Circuit Malfunction

The knock sensor is attached to the cylinder block. It senses engine knocking using a piezoelectric element. A knocking vibration from the cylinder block is sensed as vibrational pressure. This pressure is converted into a voltage signal and sent to the Powertrain Control Module (PCM) or Electronic Control Module (ECM).

Possible Causes For P0325:
- Knock sensor circuit short to ground.
- Knock sensor circuit short to power.
- Knock sensor circuit open.
- Damaged knock sensor.
- Damaged PCM or ECM

Possible Solutions:
- Repair or resecure harness or connector
- Replace knock sensor Bank 1 (Bank 1 if applicable)
- Replace PCM or ECM

The P0325 DTC is a very common problem with Nissan vehicles. On most Nissan vehicles the knock sensor is located on top of the engine block.

Hi,

The two codes seem to be related. The P0325 description is knock sensor circuit malfunction and the P1320 is ignition signal - circuit malfunction.

I'll summarize and then give links on more detailed articles I found. Basically the P0325 refers to the knock sensor and associated wiring. The P1320 refers to the ignition coil and wiring. Check the sensor, coil, and associated wiring.

I found some great articles:
P0325 - http://www.obd-codes.com/p0325
P1320 - http://autorepair.about.com/library/a/1i/bl039i.htm

Good luck!