05 random stalls - TerrainForum.net: GMC Terrain Forum
Reply
 
LinkBack Thread Tools
post #1 of 14 (permalink) Old 06-10-2017, 08:55 PM Thread Starter
Jr. Member
 
Join Date: Jun 2016
Posts: 6
05 random stalls

05 equinox, has 150k. About a month ago it just started randomly stalling.
things Ive learned: theres no rhyme or reason to when it happens, can be idle in driveway or 70mph on interstate. sometimes once a day, other times 20. it will just shut off, and pop up the low engine power light, the TC light and CE.
It will not store a code. I have to come to a complete stop, put in park and turn off key. Count to 7, turn key to start and it will just block out(as in it wont do anything) so I immediately turn key back to off, then back to start and the car will start right back up and run fine. all lights immediately go out. It has to be this routine, for example, I cannot drop down to neutral and restart as I coast. Nope, have to completely stop, put in park and turn off key. Obviously this is very dangerous, Ive had it shut off on the interstate many times.
obvious first question is have I done anything to it recently, new part, etc..the answer is NO.
so..what Have I done you ask? well, I have put on code reader to see if anything is stored. No. nothing NO DTC.
1: I have replaced the throttle body as it seems to be the most common cause from what I have seen online.
2: checked every wire from the TBI harness, all seem to be good and will not stall the car when i push and pull on them. all seem tight back to the pigtail.
3: I have redid the ground straps. as in, undid, wire brushed the contact points and rehooked.
4: I have checked wire harness on egr valve, and completely cleaned it and the tube. (I get no codes, so this was a shot in the dark.) In past exp, a bad egr valve normally makes idle and car run rough. this car runs perfect, short of the stall.
5: I have switched out the battery just to rule it out. Used new one from a friend, and car still stalled out
6: I have unhooked wheel speed sensors to see if I get a CEL when I unhook each one. I did. car still stalls
7: I have checked every fuse under hood, and inside car. all are good. I have switched around same type of relays also to rule out that.
8: I have cleaned MAF sensor and put in new air filter
9: I have pushed on connecter for trans speed sensor, as car idles, to see if it stalled. It didnt. (I tend to think its not TC related, although that does light up when car stalls, because car will stall while in park in my drive.
10: I have undid every wire group through out engine looking for bad, cut or corroded wires. There are none.
11: I have cussed and wished death upon GM for shutting car down completely instead of limp mode.

I have taken car to autozone and had them check codes just in case my reader was faulty....nothing




derekio is offline  
Sponsored Links
Advertisement
 
post #2 of 14 (permalink) Old 06-10-2017, 09:43 PM
Theta GOD!
 
Join Date: Jan 2010
Posts: 7,843
Re: 05 random stalls

Wow - you certainly are thorough, and seems to have hit upon all of the most likely causes. What bothers me is that you say you had a CEL come on, and then go off, and no codes are stored. Seems like a code should be stored for a length of time, so it makes me think that maybe your ECU is bad. or has a bad connection/bad ground.


Fortunately, you have figured out a work-around, but that is nor fool-proof.

Good luck, and report back when you do solve the mystery.

There are a few GM mechanics that are members of this forum, and possibly they may have witnessed this problem in their travels.

2010 Equinox LTZ<br />4 cyl, FWD, S/R<br />Cardinal Red/Black
RIT333 is offline  
post #3 of 14 (permalink) Old 06-11-2017, 07:30 AM
Theta Freak
 
Join Date: Feb 2011
Posts: 1,406
Re: 05 random stalls

What about the ignition switch? Maybe it's losing connection and this looks like you've turned the car off? And then you're in a weird state where the car is off but the switch is on, thus the need to turn it off for a certain amount of time to re-sync it?

I'm just guessing here, but I've seen this kind of thing happen in control systems which implement state machines. Some hardware or electrical anomaly occurs and the system is not smart enough to be fault-tolerant or self-correct.

Maybe there is a timer in the ECU logic that if you could lengthen it you could "solve" this problem. But you might also *want* to turn off the ignition in an emergency situation, so you couldn't lengthen it too much.

But again - this is just a guess...

2011 Equinox 1LT (new Jan 2011): Summit White / 3.0 L V6 / FWD / Pioneer Stereo / 18" Wheels / 108+k miles (June 2017)

2002 Impala 1LT (new Jun 2002): Summit White / 3.4 L V6 / FWD / Cassette-CD Combo /202+k miles (June 2017)
Colt Hero is offline  
Sponsored Links
Advertisement
 
post #4 of 14 (permalink) Old 06-11-2017, 10:28 AM Thread Starter
Jr. Member
 
Join Date: Jun 2016
Posts: 6
Re: 05 random stalls

interesting theory..hmm.
well, after the car stalls, I can shift to neutral and try to restart. It will turn over, but never actually catch. So i have to stop, put car in park, turn off key and then restart after a small delay. almost like some sort of sensor is failing.but no CEL which is strange . getting back to your thinking..would an ignition switch do that? it seems like if that was the case, then wouldnt all the lights on the dash illuminate, like if you HAD shut the car off while driving?
derekio is offline  
post #5 of 14 (permalink) Old 06-11-2017, 11:12 AM
Theta Freak
 
Join Date: Feb 2011
Posts: 1,406
Re: 05 random stalls

derekio:

Once again ... just guessing here, but there are interlocks designed into the system that require a defined state prior to starting the engine. So if your "Start" state has been confirmed, but something unusual or unexpected has now occurred which drops you *out* of that state, now you have to go through all the interlocks again to achieve the "Start" state again (plus maybe the additional delay, too, since this may be a "recovery" state):

1.) Park or Neutral?
2.) Vehicle Speed < 1 MPH
3.) Engine Temp < X degrees
4.) Whatever else ... maybe Brake Pedal engaged?

So maybe the engine turns over, but the interlock blocks the injector from working and the plug from firing - until the 'start' interlocks are met again.

I'd be trying to prove whether that switch is tripping out on me. Short of replacing it, you'd need a voltage readout on it. Maybe all it takes is a brief 'blip' to drop you out of the "Start" state.

=============

But here's at least one problem with all this: if it *is* the switch and the car is essentially being turned OFF, what's going on with your steering? You didn't mention any problems with that, so how is that still working with the engine OFF? Or - could it be that you are only experiencing a spurious OFF, which you cannot detect in the steering, but which is enough to fool the electronics?

2011 Equinox 1LT (new Jan 2011): Summit White / 3.0 L V6 / FWD / Pioneer Stereo / 18" Wheels / 108+k miles (June 2017)

2002 Impala 1LT (new Jun 2002): Summit White / 3.4 L V6 / FWD / Cassette-CD Combo /202+k miles (June 2017)
Colt Hero is offline  
post #6 of 14 (permalink) Old 06-11-2017, 04:10 PM Thread Starter
Jr. Member
 
Join Date: Jun 2016
Posts: 6
Re: 05 random stalls

well, I decided to mess with the ignition switch. took it off to test it, couldnt find a pinout schematic anywhere to guide me, so i just threw the money at it and replaced it.
fingers crossed but alas..it still stalled. back to the drawing board

p.s. upon stall i keep power steering
derekio is offline  
post #7 of 14 (permalink) Old 06-11-2017, 04:37 PM
Theta Freak
 
Join Date: Feb 2011
Posts: 1,406
Re: 05 random stalls

I take it you don't own an OBD-2 code reader that can log data? I bought the $99 Harbor Freight unit (with ABS). It's OK, but the information you get from it depends on the vehicle. A 2005 might not reveal much.

Knowing that the steering continues to work after the stall would've made me think twice about replacing the ignition switch. If it's electric steering, it's still getting power, and if it's hydraulic the engine is still rotating. I take it you have electric steering on that vehicle?

Fuel pump (or its electrical conductivity) cutting out intermittently?


2011 Equinox 1LT (new Jan 2011): Summit White / 3.0 L V6 / FWD / Pioneer Stereo / 18" Wheels / 108+k miles (June 2017)

2002 Impala 1LT (new Jun 2002): Summit White / 3.4 L V6 / FWD / Cassette-CD Combo /202+k miles (June 2017)
Colt Hero is offline  
post #8 of 14 (permalink) Old 06-11-2017, 05:34 PM Thread Starter
Jr. Member
 
Join Date: Jun 2016
Posts: 6
Re: 05 random stalls

the idea that it has always started right back up and runs fine has made me not think about fuel pump. The idle has always been fine and car never stumbles. it just clicks off. However, I will put a gauge on it to and see what I get.
derekio is offline  
post #9 of 14 (permalink) Old 06-12-2017, 12:58 PM
Theta Freak
 
Join Date: Feb 2011
Posts: 1,406
Re: 05 random stalls

I hear ya! Just trying to think of things that *might* be causing it, AND that wouldn't necessarily set the CEL ON.

I actually like the ignition switch theory. If not the switch, then something in that "stream" which makes the vehicle appear to be turned OFF.

This is the kind of thing where you'd like to be able to download your own "debug" version of the ECU software: put in your own data gathering hooks, build some data buffers, maybe even throw in some alarm prompts - the kinds of things the manufacturers could easily do and make available to the vehicle owner, but they never will because it would cut into their service profits.

Got computers in there, but we don't want to make them *too* smart, right?

2011 Equinox 1LT (new Jan 2011): Summit White / 3.0 L V6 / FWD / Pioneer Stereo / 18" Wheels / 108+k miles (June 2017)

2002 Impala 1LT (new Jun 2002): Summit White / 3.4 L V6 / FWD / Cassette-CD Combo /202+k miles (June 2017)
Colt Hero is offline  
post #10 of 14 (permalink) Old 06-15-2017, 11:41 PM
Hero Member
 
buggsy's Avatar
 
Join Date: Sep 2014
Location: West Wisconsin
Posts: 759
Garage
Two thoughts from all this. 1) Check your recalls. I think your ignition should have been recalled.
2) Check on a cam position sensor. If it's bad, the car will die. Kind if ties into the knock sensor.

If you have a smart phone, I recommend you get a cheap bluetooth ODBII plug in and the Torque app. Lots of great data in there.

For the power steering... I think you maintain power steering because at speed, and in gear, you are still turning the engine (and accessories) at speed.
buggsy is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the TerrainForum.net: GMC Terrain Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome