Eric Althouse

My 2006 equinox just had new front rotors and pads put on. Wife drove it to the store and the ABS and TRAC light came on. I have a pocket scanner and it showed EGR OBDII codes. Are they even related?

ruley73

While most won't think so, I believe it is possible. A while back we were having the SERVICE STABILITRAK and SERVICE TRACTION CONTROL warning messages randomly appear in the DIC (your 2006 has a different gauge cluster which doesn't have this display). The Service Engine Soon light came on at about the same time. The codes were EGR related, so I replaced the EGR valve and reset the computer. We haven't seen the warning messages since then.

If you need to replace your EGR valve, you will want to brace yourself. GM has a TSB out to replace the EGR valve in 2005-2006 Equinox to the design of the EGR valve used in 2007-2009 Equinox (3.4L). Replacing it with the newer design also requires replacing the pipe that goes to the exhaust manifold and changing the harness. You may be able to find an exact replacement for the EGR valve you have now for less, but chances are you'll end up replacing it again. There is a kit available that contains all necessary parts. There is a thread somewhere on here with this information but I can't seem to find it. I will find and post the TSB and relevant part numbers when I get home.

EDIT: The TSB (#06-06-04-008B) is in .pdf format and is a bit too large to post here.

The EGR Kit is GM p/n 89018176 or AC Delco p/n 214-2020 (see picture below). It can be purchased from RockAuto for about $180 plus shipping. Per the TSB, the ECM must be recalibrated at a dealership after installation.

tech2

the traction control system operates by using the pcm to reduce engine power. If the engine managment system has a fault, the trac system cannot work properly so the pcm disables it, sets a code and turns the light on.

momeeof2

I have a 2008 equinox. Replaced a bad hub assembly. They said the put the old sensor back on but I thought the hub assembly included a new sensor???? Stabilitrak light only came on but went off after a few cycles of the key. A few months later it came on again but shut off after a few cycles of the key.The place I bought it from said it was the EGR valve but wouldn't that make the service engine soon light come on and I would have reduced power? Then the dealership I took it to said there was a bulletin about My equinox and the EGR valve ( which was not true, but After reading the post a few spaces up I see that there is a bulletin for the EGR valve but not for my 2008 model). Dealership cleared the codes before I could take it anywhere else to get another opinion. It just came on again yesterday. It is only coming on at highway speeds and I haven't lost any power and no service engine soon light. Going to take it to have the codes read.

momeeof2

Got codes C0561, P1779, and P0404. Looking like its either the gas cap (but no service engine soon light) or the EGR valve. I think I am going to have it scanned with a more high tech scanner to pinpoint the actual cause. Anyone with input on this would be awesome.

ruley73

Not all hub assemblies include a new sensor. If you live in the rust belt they were lucky to get the old sensor out without damaging it.

If EGR-related confirmed codes are stored, this would cause the SES light to turn on. You would not have reduced power though.

If the dealership erased the codes, then you won't see any codes until after the service engine soon light comes on again. Pending codes may be seen, but those don't turn on the SES light.

FWIW, on our Equinox the Service Stabilitrack & Service Traction Control messages started appearing a few months before the SES light came on due to the bad EGR valve. At first those messages usually appeared when driving down the highway at a steady speed, but eventually they started appearing randomly regardless of the type of driving. Just like in your case, the messages would always disappear after a few ignition key cycles.


I'm certain that the gas cap is not a factor with any of those codes. A shop will need to check things out with a good diagnostic tool. If your Equinox is a 2005-2009 with the 3.4L then there's a good chance that the EGR valve is bad.

momeeof2

We are going to replace EGR valve. I know what to expect with a bed wheel sensor and its not doing that. Thank you. I'll keep you posted.

momeeof2

So, before we got the EGR valve replaced, my service engine soon light came on and transmission started shifting bad. Had a transmission shop run the codes and couldn't find anything internally wrong but still got p1779 code. Changed the EGR valve lastnight and still shifting weird. Anyone else have this problem and did it go away after the codes were cleared?

ruley73

Did you reset the computer after replacing the EGR valve? Disconnecting the negative cable from the battery is the hard way, removing fuse #33 from your underhood fuse block for a couple minutes is the easy way.

I already replaced the EGR valve a few years ago, but recently we have been seeing the "Service Stabilitrak" & "Service Traction Control" messages again. It seems to be pretty random, but so far it has only occurred when cruising down the highway. I am retrieving the same codes (C0561, P0404, P1779) with a scantool, but the P0404 & P1779 codes I saw are "intermittent" or "pending" codes which do not trigger the check engine light to come on. In my case the transmission shifts fine even with these stored cods/faults. Can you elaborate what you mean by "shifting bad?"

When I get a chance I plan to inspect the EGR valve for carbon build-up and the EGR valve wiring to see if I can find anything wrong. I recall not seeing anything wrong when I replaced the EGR valve a few years ago.

momeeof2

Yes, I had the codes cleared after repair. The transmission feels like it's slipping from 2 to 3 gear.