16716 - Knock Sensor 2 (G66): Signal too Low *What to Check and How?*

[getslideways]

So i keep VAGing my car and getting this:

16716 - Knock Sensor 2 (G66): Signal too Low

It doesn't cause a CEL but keeps showing up in the scans. what should i do to check the sensor. Anyone have any tips? One thread said it was under the intake near the firewall. I was just wondering if there was a way to check the sensor, or if there were any tips to gain access to it. Am i going to have to pull the intake manifold out to get to it? Thanks!

[MattzWarsteiner]

Probably a loose connection or bad sensor.

See the Ross-Tech wiki on this here.

[getslideways]

Thanks for the wiki link!

does anyone know if this would cause the car to be put into limp mode or not?

[Nebone]

Knock sensor issues are not cool man. I been dealing with a "Signal too High" issue recently. What year is your car? I have discovered an error in the Bentley manual. The G66 sensor is the sensor between cylinder 3 and 4. It's REALLY hard to see it so you'd have to dig in there. First, check the connector. It should be blue and its under the coolant bottle.

This can definitely put you into limp mode as the ECU is not getting correct readings and is trying to protect the engine by just reducing timing and power.

[CO AVANT]

Some can get to it without taking the IM off. I retorqued mine last week but had the IM off cause I was replacing my thermostat. Torque spec is 20NM.

[getslideways]

What year is your car? I have discovered an error in the Bentley manual. The G66 sensor is the sensor between cylinder 3 and 4. It's REALLY hard to see it so you'd have to dig in there. First, check the connector. It should be blue and its under the coolant bottle.

This can definitely put you into limp mode as the ECU is not getting correct readings and is trying to protect the engine by just reducing timing and power.

thanks for the help i will have to check that connector, my car is a 2000 ATW

is there anyway to test the sensor itself, such as maybe a resistance test at the connector?

[getslideways]

I checked the connectors under the coolant reservoir, there were 3 (from pass side to driver side) light blue, blue, and a green connector. I pulled the light blue and blue connectors apart (didn't check the green one) and reconnected them and the terminals seemed clean. I haven't had a chance to clear the codes yet on account of it raining to see if it will make a difference.

[Jeff]

A knock sensor is a small microphone that is surrounded by a silicone-line gel that helps it absorb and detect knock. Through time, this gelly gets old and begins to crack and sometimes simply just deteriorates, causing a low signal--because the sensor itself can no longer accurately pick up the sounds through the block.

I would replace it immediately, and make sure you replace the bolt and properly torque it. #1 is much easier to get to. #2 is a PITA. I would also buy a NEW unit, and not a used unit. With the car not being able to properly detect knock, you can either go into limp mode... while in some cars you can do some severe damage because you're knocking and the ECU can not pick it up and take precautions.

[killa]

you need to torque it properly