syncopated

Hi,

Long time reader, first time posting. I have a 2011 Q5 3.2l and recently had a very weird issue occur. I'm hoping that someone can shed some light and possibly explain. I never really use the cruise control and last week I activated cruise control and the car was driving fine. However, at some point that same day my check engine light went appeared. I had the code checked and it was the knock sensor P0237. My mechanic took a look and apparently the way the code was registered he said it might have been electrical and reset the code. I had no loss of power, the car drives exactly the same. I explained that I thought it was triggered from the cruise control. He told me that he didn't think so, but he will reset it and I will drive it if the code doesn't appear then try engaging the cruise control again and see what happens. I did that and in the morning I used the cruise control and then later that day the check engine light appeared with the same code.

Please help with valuable insight, THANK YOU in advance.

1. Is this possible - Is the cruise control related in an electrical manner to trigger the sensor?

2. Carbo Build Up - My model is know for the carbon build up, can this be related and do you know if the P0237 is the code for the dealer to do the job under warranty?

3. Reset Check Engine light - Is there a quick way to reset the light myself so I don't have to make a special trip to the mechanic and I can do the same test again?

4. I welcome any other ideas to test this out and troubleshoot.


Thanks again.

Bob Petruska

That code can be many things, from MAP sensor, to turbo boost control circuit.

Disconnecting the battery should erase the code, but not positive on that.

It might be wise to invest in a very cheap scanner, such as this one, to read codes and erase them. This one works great on the Q5, it only reads the generic codes (P0237, etc.), not the more sophisticated codes that a much more expensive VCDS scanner will.

https://www.ebay.com/itm/MS300-CAN-O...8AAOSwY4Fa-~E4

syncopated

Hi,

Thank you for the reply. I'm looking forward to being a member of this forum.

I will buy that scanner, it's a great idea.

The code is actual P0327, I flipped the numbers. This is related to the knock sensor, however, it's odd because it occurred twice and both times when I engaged the cruise control. Is this some how related or electrical?

This afternoon after driving a full day, the check engine light went off. I read some where that this happens if it's not a persistent issue and something just triggered the error electrical, is this true?

Does anyone know if this is a sign of carbon build up and the right code for the deal to cover the issue?

Thank you so much for the great feedback.

Redd

Bob-
I thought we were never supposed to disconnect the battery (even when replacing it) because so many things were memorized in the computers and they could all be reset with a loss of power?

Sync-
The problem with a car that is infested with a mess of computers and electronics sharing communications busses, is that a stray voltage of signal anyplace in the system can interact with something totally removed from it. It is possible that the engine controls that the cruise control is using, are conflicting with the signals that the knock sensing system is using. And those will be interacting with fuel and air sensors and the injectors, and sometimes some of those need to be replaced between 50-100,000 miles as routine maintenance.
Also, there COULD be a known issue and a good shop (or the dealer) would be able to pull that up and check on it. You might contact Audi directly to ask if there are known issues about this, and if a software update is available to remedy that. (Asking is free, right?)

"The only good computer is a dead computer." [Will Rogers]

Bob Petruska

True, I had a senior moment. I keep forgetting that the Audi system is a strange beast compared to other vehicles

Redd

Don't you dare have any senior moments, that's my job. I'm going to report this to the shop steward and file a complaint immediately.
Remind me again, will you? Who's the shop steward?

Bob Petruska

Redd

And here I thought that whether the ignition was on or off, the computers would still be wiped when they ran out of electricity, i.e. when the battery was disconnected.

Then I realized, of course, if the ignition is on, the battery cable electrohydraulic docking security clamps will still be engaged. Unauthorized personnel will not be allowed to tamper with the flow of electricity. (What, your car is so old it doesn't have that?(G)

Bob Petruska

I thought that the muffler bearings did all that.....................