Where is the knock sensor

Check engine light on ? What code ? There are many different (DTC'S) - diagnostic trouble codes that can set for knock sensors ! There all don't mean that you replace the sensor .
DTC P0324: Knock Sensor (KS) Module Performance
DTC P0325: Knock Sensor (KS) Circuit Bank 1
DTC P0326: Knock Sensor (KS) Performance
DTC P0327: Knock Sensor (KS) Circuit Low Bank 1
DTC P0328: Knock Sensor (KS) Circuit High Bank 1
DTC P0330: Knock Sensor (KS) Circuit Bank 2
DTC P0332: Knock Sensor (KS) Circuit Low Bank 2
DTC P0333: Knock Sensor (KS) Circuit High Bank 2

The knock sensor (KS) system enables the control module to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The sensors are located below each cylinder head on the engine block. The KS produces an AC voltage signal that varies depending on the vibration level during engine operation. The control module adjusts the spark timing based on the amplitude and the frequency of the KS signal. The control module receives the KS signal through 2 isolated signal circuits. The control module learns a minimum KS noise level at idle and uses calibrated values for the rest of the RPM range. The control module should monitor a normal KS signal within the noise channel.
Knock Sensor Replacement - Bank 1
Remove the exhaust manifold lower heat shield. Refer to Exhaust Manifold Lower Heat Shield Replacement.
Disconnect the engine wiring harness electrical connector (1) from the bank 1 knock sensor (2).
Loosen the knock sensor bolt and remove the knock sensor.
Knock Sensor Replacement - Bank 2
Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
Remove the engine oil filter. Refer to Engine Oil and Oil Filter Replacement .
Lower the vehicle.
Disconnect the engine wiring harness electrical connector (2) from the bank 2 knock sensor (3).
Loosen the knock sensor bolt and remove the knock sensor.

Knock Sensor

Print
Operation

The Knock Sensor (KS) is a tuned accelerometer on the engine which converts engine vibration to an electrical signal. The PCM uses this signal to determine the presence of engine knock and to retard spark timing.
Removal & Installation

1. Raise and safely support the vehicle.
2. Remove the intake manifold.
3. Remove the bolt and the Knock Sensor (KS).
4. To install, reverse the removal procedure and tighten mounting bolt to 15ft. lbs. (20 Nm).

Inspect/Test/Replace

A defective knock sensor may cause engine detonation or reduced spark advance and fuel economy. When a knock sensor is removed and replaced, the sensor must be tightened to its specified torque. If the knock sensor is installed tighter than it should be, it may become too sensitive and provide an excessively high voltage signal, resulting in more spark retard than required. When the knock sensor is installed looser than it should be, the knock sensor signal will be lower than normal, resulting in engine detonation.

To replace the knock sensor:

• Disconnect the knock sensor wiring connector.


• Then, unscrew the sensor.


• Remove the knock sensor.


• Reverse the procedures to install the part.

1. Raise and safely support the vehicle.
2. Remove the tire to ease access to the knock sensor.
3. Remove knock sensor shield
4. Remove the connector from the knock sensor.
5. Remove the sensor mounting bolt,
6. Now remove the knock senor.
7. To install reverse the steps above and tighten the bolt to 18 pounds torque.
8. See diagrams for additional help. Note there is one on each side of the engine.

• Hope this helps and thank you for using FixYa.

Regards, Tony

Hello adamjerkins,

It is somewhat complicated to change the knock sensors. There are two of them and they are located under the intake manifold. The intake manifold must be removed. I would recommend tha you replace both while you have the engine apart.

What leads you to believe the knock sensors are bad, I've seen few bad knock sensors? The knock sensor issues more times than not have been caused by other problems.

After you remove the intake manifold disconnect the knock sensor connectors. Remove the bolts and the two knock sensors then replace with new knock sensors tighten the bolts to 15 foot pounds. Reinstall manifold. The total job for an experienced mechanic with tools is about 5 hours. Not a good job for a beginner.


Regards,
netvan

First, I would like to mention that most knock sensor codes are not caused by the knock sensors, but a mechanical problem with the engine. The knock sensors cannot differentiate between noises caused by mechanical problems like a bad pulley bearing, bad motor mount, noisy alternator bearings, etc. and spark knock. knock sensor codes are set when the computer has retarded the timing as far as possible to compensate for ignition ping (Spark Knock) and the noise still exists.

With that said, here are the instructions.

Remove the Intake Chamber assembly.
Disconnect Injector connectors.
Disconnect the heater hose from the Intake Manifold.
Remove the 9 bolts. 2 nuts, 2 plate washers and Intake Manifold assembly.
Remove right hand engine mounting stay and water outlet.
Disconnect the following hoses and connectors:
Radiator inlet hose.
Engine coolant reservoir hose.
Engine Coolant Temperature Sensor connector.
Engine Coolant Temperature Switch connector.
Ground strap connector.

Remove the 3 bolts and right hand mounting stay.
Remove the wire band.
Disconnect the water bypass hose from the inlet housing.
Remove the 2 bolts, 2 nuts, 2 plate washers and water outlet.
Remove the 2 gaskets.
Disconnect the Knock Sensor connectors.
Remove the Knock Sensors.

It's located deep in the valley! Under the "LOWER intake manifold". copy and paste this link in your browser, or try clicking on it. It may be helpful to you.

http://x.nissanhelp.com/forums/pathfinder/7890-3-3l-knock-sensor-relocation.html

I didn't find this link until after I had already disassembled my truck. This is the hardest job that I've taken on thus far, hope I can put it all back together properly. I changed the gaskets on the valve covers since I had everything off.
To answer your question: It's under your lower intake manifold, so it's a hard job!

You didn't list your engine size so please pick the applicable to your motor size:

Removal & Installation 2.8L & 2.9L Engines To Remove:

1. Lift the vehicle high enough to gain access to the knock sensor (KS) through the left front wheelhouse.
2. Remove the left front wheel and wheelhouse liner.

Knock sensor (KS) (A), Engine harness (B), Knock sensor (KS) connector (C)

1. Disconnect the knock sensor (KS) connector.
2. Detach the knock sensor (KS) from the engine block.

To Install:

1. Attach the knock sensor (KS) to the engine block.
   • Tighten the bolt to 18 ft lbs (25 Nm).
2. Connect the knock sensor (KS) connector.
3. Install the left front wheelhouse liner and wheel.
4. Fully lower the vehicle.

Your knock sensor is located Under the hood, center, front engine area, below intake manifold, mounted on block.


A defective knock sensor may cause engine detonation or reduced spark advance and fuel economy. When a knock sensor is removed and replaced, the sensor must be tightened to its specified torque. If the knock sensor is installed tighter than it should be, it may become too sensitive and provide an excessively high voltage signal, resulting in more spark ****** than required. When the knock sensor is installed looser than it should be, the knock sensor signal will be lower than normal, resulting in engine detonation.

To replace the knock sensor:

• Disconnect the knock sensor wiring connector.
• Then, unscrew the sensor.
• Remove the knock sensor.
• Reverse the procedures to install the part.

The knock sensor threads into the side of the cylinder block.

1. Disconnect electrical connector from knock sensor.
2. Use a crow foot socket to remove the knock sensors.

INSTALLATION
The knock sensor threads into the side of the cylinder block in front of the starter.

1. Install knock sensor. Tighten knock sensor to 10 Nm (7 ft. lbs.) torque. Over or under tightening effects knock sensor performance, possibly causing improper spark control.
2. Attach electrical connector to knock sensor