Got the P0332-Knock Sensor 2 (G66) Code

[jeremy2525us]

Hey guys! Ran a diagnostics on my S4 today and found this code. I can't seem to find where the Knock sensor is located in the engine compartment. And would this issue cause acceleration hesitation? How hard of a fix is this? Thanks for any help.

[Zolli]

There’s three knock sensors (if I recall correctly), and they are all located under the intake manifold. I think they have blue wiring harness connectors that are located at the top front of the engine.

I am 99% sure the knock sensor would not cause the acceleration hesitation. If you didn’t get any misfire codes, then I would bet that your intake manifold flap is seized or sticking, possibly a vacuum leak.

Not that hard to do, but you will need to remove the intake manifold to get at them. Might as well change the valley pan gasket, oil filter housing, and oil check valves while you’re there. Actually, you might as well put a supercharger in there while you’re at it! Lol sure, sure....

Hopefully q_dubz or quikrnu or VinnysS4 will chime in with some real answers.

[All_Black_A4]

I thought there was 4 of them. 2 on each side under the IM with blue and black connectors at the ends.


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[Zolli]

I thought there was 4 of them. 2 on each side under the IM with blue and black connectors at the ends.


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Hm yes I think you’re right: two blue, two black. Obviously this means the photos I took from the last time I was in there are rubbish.

[roboto_1337]

4 knock sensors yes... I haven't heard of rod or main bearing failure, but it is possible. If there is a rod knock you should be able to hear it, when you tap the accelerator... it will be subtle. Misfire causing knock would give you a misfire code, it is likely that one of the knock sensors has failed... which is best case scenario. I'll see if I can get an image of which one it is.

The pictures in the manual aren't very good, but the connections for the sensors are on the front of the intake manifold, below the vacuum actuator for the flap.

[roboto_1337]

Knock Sensors, Checking
The following procedure is used to diagnose all Knock Sensors .

Special tools, testers and auxiliary items required Multimeter .

Wiring diagram.

Test requirements

The mounting bolt of Knock Sensor (KS) 1 G61 / Knock Sensor (KS) 2 G66 / Knock Sensor 3 G198 / Knock Sensor 4 G199 tightened to 20 Nm.

The Motronic Engine Control Module (ECM) J623 fuses OK.

Battery voltage at least 12.5 volts.

All electrical consumers such as, lights and rear window defroster, switched off.

Vehicles with automatic transmission, shift selector lever into position "P" or "N" .

A/C switched off.

Ground (GND) connections between engine/transmission/chassis OK.

Ignition switched off.

Procedure

Remove the engine cover with air filter Fuel Injection and Ignition - Repair Group 24 .

Note:

Before disconnecting the Knock Sensor electrical harness connectors, mark the component location.

Disconnect the green Knock Sensor (KS) 1 G61 electrical harness connector - 1 - or the gray Knock Sensor (KS) 2 G66 electrical harness connector - 2 - .

or Knock Sensor 3 G198

or Knock Sensor 4 G199

Checking internal resistance

Using a Multimeter , check each Knock Sensors' terminals 1 to 2 for an internal short.

Specified value: ∞ (Infinity).

If the specified value was not obtained:

Replace the faulty Knock Sensor (KS) 1 G61 / or Knock Sensor (KS) 2 G66 /or Knock Sensor 3 G198 /or Knock Sensor 4 G199 Fuel Injection and Ignition - Repair Group 24 .

If the specified value was obtained:

Checking wiring

If the manufacturers test box is being used. Perform the following step.

Install the test box. Refer to Fuel Injection and Ignition - Repair Group 24 .

If the manufacturers test box is not being used. Perform the following step.

Remove the Motronic Engine Control Module (ECM) J623 . Refer to Engine Control Module, Replacing

Using a Multimeter , Check the Knock Sensors' electrical harness connectors to the Motronic Engine Control Module (ECM) J623 electrical harness connector T121 for an open circuit.

Knock Sensor (KS) 1 G61 electrical harness connector terminals Motronic Engine Control Module (ECM) electrical harness connector T121 terminals or test box sockets
1 99
2 106
3 93
Knock Sensor (KS) 2 G66 electrical harness connector terminals Motronic Engine Control Module (ECM) electrical harness connector T121 terminals or test box sockets
1 99
2 107
3 93

Knock Sensor (KS) 3 G198 electrical harness connector terminals Motronic Engine Control Module (ECM) electrical harness connector T121 terminals or test box sockets
1 99
2 31
3 93

Knock Sensor (KS) 4 G199 electrical harness connector terminals Motronic Engine Control Module (ECM) electrical harness connector T121 terminals or test box sockets
1 99
2 16
3 93

Specified value: 1.5 Ω Max.

If the specified value was not obtained:

Check the wiring connection for an open circuit, short circuit to Battery (+) or Ground (GND).

Check the wiring connection for damage, corrosion, lose or broken terminals.

If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring and the resistance was not OK:

Replace the faulty Knock Sensor (KS) 1 G61 / Knock Sensor (KS) 2 G66 / or Knock Sensor 3 G198 / or Knock Sensor 4 G199 Fuel Injection and Ignition - Repair Group 24 .

If no malfunction is found in the wiring and the resistance was OK:

Replace the Motronic Engine Control Module (ECM) J623 .

Install the engine cover with air filter Fuel Injection and Ignition - Repair Group 24 .

Final procedures

After repair work, the following work steps must be performed in the following sequence:

Check the DTC memory. Refer to .
If necessary, erase the DTC memory. Refer to .
If the DTC memory was erased, generate readiness code. Refer to .

End of diagnosis.

[roboto_1337]

knock sensors.jpg

The numbers on here do not refer to the knock sensor numbers. I believe the Grey one is #2 from the previous post. This is simply a picture so you know what they look like under the intake manifold.


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[jeremy2525us]

Thanks everyone for the replies. And roboto_1337, thanks for the incredible details on the procedure. I'm gonna have to see how much I can do on my own.

[jeremy2525us]

I also forgot to mention that my resting battery Voltage was about 11.87. I'm pretty sure it should be at 12V when not running. Could that cause any issues with the sensors? Or anything else? Thanks again, guys!

[roboto_1337]

I also forgot to mention that my resting battery Voltage was about 11.87. I'm pretty sure it should be at 12V when not running. Could that cause any issues with the sensors? Or anything else? Thanks again, guys!

I don't think it would cause issue with the testing, the voltage drop is negligible. If you start the car up and measure the voltage you should be able to see what the alternator is putting out, and that'll be what the sensors normally run off of... checking the voltage is more for an accurate resistance drop I believe.

[Zolli]

I don't think it would cause issue with the testing, the voltage drop is negligible. If you start the car up and measure the voltage you should be able to see what the alternator is putting out, and that'll be what the sensors normally run off of... checking the voltage is more for an accurate resistance drop I believe.

I agree. However your battery resting voltage should be around 12.7 and up around 13.5-14.5 when the car is running.

[jeremy2525us]

So I checked the connections and wiggled them a bit and then did another diagnostic. The code is gone, but not sure if it will last. I will do another test after driving for a bit. Crossing my fingers it was just a loose connection. Thanks for the continued support.

[roboto_1337]

Here’s hoping. I think those sensors are pretty reliable. Not a lot to them.


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