07 MDX Warning lights: Check Emission and Check SH-AWD

[benlee78]

I purchased the CPO 07 MDX with (36K miles) back in August 2010. Recently whenever its gets in the frigid temperatures, I would get the warning message for Check Emission and Check SH-AWD. This has been happening on and off for a few of weeks. With the warning lights, I dont notice any change to the performance. I do notice when you switch the options to view the AWD performance on the screen, is see the bars operating for the front wheels but I dont see the bars operating for the rear wheels.

When the weather is not so cold, the warning lights dont appear. Ive checked the gas cap and its tightly closed. Not sure if this is a known issue but Im going to have it checked out on Thursday.

[benlee78]

Heres a picture of my MDX

[benlee78]

Heres a picture:

[adr5]

I would take it back to the dealer and have them check it out. That should not be happening. Sounds like there is a problem with your system.

I noticed from the picture you posted that your car has wheels form the later 2010 car.

[fx.chip]

Seems like your front wheels are doing all the work, you need a dealer visit immediately.
Please keep us updated on the dealer response and repairs done.

[benlee78]

I got it resolved. I dont have the paper work in front of me but I think they said they changed the "valve" or something like that because there were a build up of carbon. Once I have the paper work in front of me, Ill try update you guys.

He said this can happen to some vehicles with high mileage, but since I only had 48K miles, he asked if I was using Premium (which I was from day 1). I assume the previous owner may have been using non-premium gas? Not sure.

[benlee78]

Originally Posted by adr5

I noticed from the picture you posted that your car has wheels form the later 2010 car.

Yes, I purchased the 2010 base rims. I didnt like the 2007 base rims.

[benlee78]

Sorry for the long wait. Ive been looking around the house and cannot find the print out from the dealership. Overall, Im not experiencing these issues anymore. But if I do find it, I will update this later.

[pootie316]

Ever figure out what the fix was? My car is starting to do it intermittently. Seemed to do it only when it was really cold outside. Now it's doing it even in the warmer temperatures. Thought it was gas cap. Seemed to fix it self shortly after I would click the gas a few more times. Bought a new cap and it still does it.

Was a new EGR valve the fix for yours? Checked the manifold ports and they're clean. Hate to buy a new EGR valve and that's not it. So hard to diagnose an intermittent light.

[Snow White]

Your best bet to get an answer from benlee78 would be to send him a private message as he hasn't been active since 10-29-2012 10:34 AM. A private message should send an email alert if it has not been turned off in his user settings.

[benlee78]

Sorry I havent been on this site for a while. I dont own an MDX anymore even though it was a very nice SUV. When I showed the dealership of the issue, they first asked if I used regular gas and I said no. Since I bought the MDX CPO, I think maybe the previous owner was not using premium gas and was using regular gas. Maybe driving on regular gas damaged the valve? So I dont remember the details of the valve but based on my previous post, he changed some kind of valve. I dont have the paper work so Im not sure what the details were. Sorry for the lack of info.

[AC_MDX]

Use an OBDII scanner to find out what are the codes so that you can understand exactly where the issue is coming from. Almost looks like the engine computer is detecting some mis-firings (or a catalytic converter working at below specs) and is turning off the SH-AWD. Misfiring don't have to be noticeable for the engine computer to detect it and once they repeat enough times, the computer will turn off the SH-AWD.

AC

Originally Posted by pootie316

Ever figure out what the fix was? My car is starting to do it intermittently. Seemed to do it only when it was really cold outside. Now it's doing it even in the warmer temperatures. Thought it was gas cap. Seemed to fix it self shortly after I would click the gas a few more times. Bought a new cap and it still does it.

Was a new EGR valve the fix for yours? Checked the manifold ports and they're clean. Hate to buy a new EGR valve and that's not it. So hard to diagnose an intermittent light.

[NewMDXOwner]

My car had done it a few times, and each time it's the carbon build up in the Idle Air Control valve, a.k.a. IAC. Take it out and clean out the carbon deposits with some Throttle Body Cleaner, and you will be good for another 40k miles. That's for a 2001-2002 MDX. The later models don't seem to have much of this problem.

[siren001]

I took delivery of a 2013, and is showed this same thing 2 days later. along with the check trailer assist, and check VSA,

They are replacing the PCM

[pootie316]

Finally fixed my intermittent check light. Would've fixed it earlier but I was in the middle of a move so I didn't have my tools and had to guess and do the best I could.

A little background. I had an intermittent "insufficient EGR flow" light. With the tools i had, I was able to take off the intake manifold covers and inspect the egr ports like many say is the culprit. They were clean as a whistle. Was never able to take the EGR valve off because i didn't have any extensions to get down there.

Well, finally got my tool box out of storage and immediately took the EGR valve off. Upon inspection, there was carbon built up all around the valve. Scraped it all out and reinstalled valve. BAM!!!! No more light for two weeks now.

So for those with P0401, if I remember correctly, I would look at the EGR valve first, since it's only 2 nuts to remove. I ended up breaking my engine cover when removing it to inspect the manifold ports since it was so brittle due to the extreme cold.