Knock sensor reading and location

Good afternoon,

The knock sensor detects detonation in the cylinder and tries to stop it by retarding the timing to cool down the cylinder temperature.

Do you have a scan tool that can monitor the action of the sensor? With a scan tool hooked up, and the engine running, tap the top of the engine and watch the timing change in live data. That will tell you if it is working.

Roy

PURPOSE
The ECM/PCM monitors the ESC signal to determine when engine detonation occurs

OPERATION
The Electronic Spark Control (ESC) system is comprised of a knock sensor and the ECM/PCM. The knock sensor is located in the engine block and sends a signal to the ECM/PCM to retard ignition timing during a spark knock condition. When the knock sensor detects detonation, the ECM/PCM retards timing in small increments of 2° (up to 10°) to reduce detonation. This allows the engine to use maximum spark advance to improve driveability and fuel economy.

The Mem-Cal used with this engine contains the functions which were part of remotely mounted ESC modules used on other GM vehicles. The ESC portion of the Mem-Cal then sends a signal to other parts of the ECM which adjusts the spark timing to retard the spark and reduce the detonation.

LOCATION
The knock sensor is located in the engine block.

DIAGNOSTIC NOTES:
Retarded timing can also be a result of excessive valve lifter, push-rod or other mechanical engine or transmission noise.

You could back probe the sensor while plugged in and check the voltage but it may not read the voltage fast enough to see the change.

Do not measure ohms, measure voltage.

Roy

It is mounted to the block under the exhaust manifold as in the picture. It has a single wire connector to it and there was also a picture of the sensor.

It is at the back side of the motor. You will need a lift to get to it.

Roy

Good afternoon again,

I do not see nor have I ever removed the intake for the sensor.

Can you take a picture of where it tells you this procedure?

The sensor pays.9 hours or 54 minutes from start to finish. That does not require the removal of the manifold.

Roy

Back when we had the other post, I told you that it has to be accessed from the bottom. I included a picture of the location.

If anything would come off to make it easier, the exhaust manifold is close to it.

Look up underneath with it jacked up. You will see it there. You will need small fingers to get it.

Roy

It is on the back of the motor under the exhaust manifold. You should see it when you have it raised in the air.

Roy

Yes, .9 hours should be close to that depending on the shop's labor rate.

Roy