CEL came on yesterday, 2006 ODB trouble codes

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

OR VietVet

GMT800 2005 Tahoe Z71
Navy Supporting Member
Joined
Oct 8, 2014
Posts
23,905
Reaction score
44,597
Location
Willamette Valley
Ron, does your video from the other vehicle apply to this, or are they essentially different parts?

Yes, that is the first one and should basically apply to yours as well. If you look closely, you will see a "fat" area in the gears that shows at the edge of the switch. I found that is the wrong position, at least on the TrailBlazer anyway, and that fat area should be rolled one toot over to where the fat area disappears. If you go back to you tube and see, there will be a "correction" video for the same switch and an explanation.
 
OP
OP
2

2006Tahoe2WD

Full Access Member
Joined
May 24, 2015
Posts
545
Reaction score
366
Location
Silicon Valley
I still don't think I have the gear correctly aligned. One thought.
Get the key to the pull it out (off) position and then move the switch by hand with the switch pulled down to find the middle of the "off" position. This means moving the switch around with the battery connected?
 

OR VietVet

GMT800 2005 Tahoe Z71
Navy Supporting Member
Joined
Oct 8, 2014
Posts
23,905
Reaction score
44,597
Location
Willamette Valley
I still don't think I have the gear correctly aligned. One thought.
Get the key to the pull it out (off) position and then move the switch by hand with the switch pulled down to find the middle of the "off" position. This means moving the switch around with the battery connected?
Disconnect the negative battery cable each time. Look at the second video. It explains what I am talking about and shows a comparison.
 
OP
OP
2

2006Tahoe2WD

Full Access Member
Joined
May 24, 2015
Posts
545
Reaction score
366
Location
Silicon Valley
I watched both videos. I see the moving over a bit or one tooth. There wasn't much said about where the key was. I assume in the "off" position instead of the acc. position.
In any case my situation is like the last video where is almost doesn't start - so I need to go at least one tooth over (more toward start) than what I have.
 
OP
OP
2

2006Tahoe2WD

Full Access Member
Joined
May 24, 2015
Posts
545
Reaction score
366
Location
Silicon Valley
Anyone have handy the pin descriptions for the switch?
Or the page in a diagram showing the switch where I might tell what each pin is.
I'm thinking I can put an ohm meter on the old switch and lean about the rotation positions/limits for each function.
Thanks.
 

OR VietVet

GMT800 2005 Tahoe Z71
Navy Supporting Member
Joined
Oct 8, 2014
Posts
23,905
Reaction score
44,597
Location
Willamette Valley
I watched both videos. I see the moving over a bit or one tooth. There wasn't much said about where the key was. I assume in the "off" position instead of the acc. position.
In any case my situation is like the last video where is almost doesn't start - so I need to go at least one tooth over (more toward start) than what I have.
Yes, the key is in the off position. You can see no key in the videos. If I had it in any other position, besides off, the key would not come out.
 
OP
OP
2

2006Tahoe2WD

Full Access Member
Joined
May 24, 2015
Posts
545
Reaction score
366
Location
Silicon Valley
okay, makes sense.
The pins positions are labeled A, B, C (B has a ground symbol) next row is D, E, F, G.
Can someone look up the descriptions? I don't have Alldata and so far can't find a free list.
 
OP
OP
2

2006Tahoe2WD

Full Access Member
Joined
May 24, 2015
Posts
545
Reaction score
366
Location
Silicon Valley
I'm feeling the old switch. It has 3 detents and a spring loaded feel on one end (starting mode).
1 - accessory
2 - off
3 - run
4 - spring rotate to start
With the key out (off) I need to put the switch on the "off" detent and then slide in the switch.
Does that make sense? That method is not described in the videos.
 

OR VietVet

GMT800 2005 Tahoe Z71
Navy Supporting Member
Joined
Oct 8, 2014
Posts
23,905
Reaction score
44,597
Location
Willamette Valley
I'm feeling the old switch. It has 3 detents and a spring loaded feel on one end (starting mode).
1 - accessory
2 - off
3 - run
4 - spring rotate to start
With the key out (off) I need to put the switch on the "off" detent and then slide in the switch.
Does that make sense? That method is not described in the videos.
Frankly, I did not care about what circuit was effected by the gear teeth location. If I had a vehicle that was cranking and starting and then was not and I was replacing the ignition switch, I am going to replace with the gear teeth in the same position. I showed on the 2 videos where the teeth are located and what I did. It now works after correcting the teeth alignment. I can now sleep at night.
 
OP
OP
2

2006Tahoe2WD

Full Access Member
Joined
May 24, 2015
Posts
545
Reaction score
366
Location
Silicon Valley
I'm reminded of something my Dad used to say. If all else fails try reading and following the directions. Well.... I thought what about looking in the manual. Guess what ? I thought the far counterclockwise direction was ACC. It is not - it is the "LOCK/OFF" position (key can come out). The next position in the clockwise direction is ACC, then RUN, then START.
The 2006 doesn't have the steering wheel lock feature. Not sure about other nearby years.
 
OP
OP
2

2006Tahoe2WD

Full Access Member
Joined
May 24, 2015
Posts
545
Reaction score
366
Location
Silicon Valley
Update - I moved the gear over about 1 tooth. All works good now.

I'm now starting to dig into the P0442 code.
I hooked up my code/scanner tool and got the purge valve to come on and watched the fuel tank pressure go down. When I shut the purge valve off the fuel tank pressure came back up to ~0 very quickly. I took the purge valve out and pulled a bit of a vacuum with my mouth and it held. I also noticed when I manually opened the purge valve with the scanner there was a stumble in the idle. The gas cap O ring and seal looked okay - no cracks in the O ring.
I don't have a smoke tester - what can I do next?
Thanks.
 

Fless

Staff member
Moderator
Joined
Apr 2, 2017
Posts
16,612
Reaction score
34,385
Location
People's Republic of Colorado
So I understand it, it sounds like you did a purge and seal test, but the vacuum that was applied during the purge didn't hold after the seal, and the fuel tank pressure returned to atmospheric pressure very quickly. Do I have that right?

When you removed the purge valve, what did you pull a bit of a vacuum with your mouth on? The purge valve, or the intake?

And yes, at idle, when the purge valve is opened the idle will get rough and the engine won't be very happy. Normal.

Purge valves (as well as vent valves) can be intermittent, so be careful with that.

EDIT: you can test the vent valve to be sure it's closing mechanically and electrically.
 
Last edited:
OP
OP
2

2006Tahoe2WD

Full Access Member
Joined
May 24, 2015
Posts
545
Reaction score
366
Location
Silicon Valley
So I understand it, it sounds like you did a purge and seal test, but the vacuum that was applied during the purge didn't hold after the seal, and the fuel tank pressure returned to atmospheric pressure very quickly. Do I have that right?

When you removed the purge valve, what did you pull a bit of a vacuum with your mouth on? The purge valve, or the intake?

And yes, at idle, when the purge valve is opened the idle will get rough and the engine won't be very happy. Normal.

Purge valves (as well as vent valves) can be intermittent, so be careful with that.
Not 100% sure I did the purge and seal test correctly. I did see the purge valve open in a percentage manner on the reader and the fuel tank pressure went down. I pulled the vacuum in both directions on the purge valve and didn't feel an obvious leak.
It seems like when the purge valve closes the negative pressure should stay or decline slowly.
 
Last edited by a moderator:

OR VietVet

GMT800 2005 Tahoe Z71
Navy Supporting Member
Joined
Oct 8, 2014
Posts
23,905
Reaction score
44,597
Location
Willamette Valley
Update - I moved the gear over about 1 tooth. All works good now.

I'm now starting to dig into the P0442 code.
I hooked up my code/scanner tool and got the purge valve to come on and watched the fuel tank pressure go down. When I shut the purge valve off the fuel tank pressure came back up to ~0 very quickly. I took the purge valve out and pulled a bit of a vacuum with my mouth and it held. I also noticed when I manually opened the purge valve with the scanner there was a stumble in the idle. The gas cap O ring and seal looked okay - no cracks in the O ring.
I don't have a smoke tester - what can I do next?
Thanks.
You moved the tooth over 1 tooth? You rolled the fat/wide spot where it is hidden/cannot be seen and now all is good? Correct?
 

OR VietVet

GMT800 2005 Tahoe Z71
Navy Supporting Member
Joined
Oct 8, 2014
Posts
23,905
Reaction score
44,597
Location
Willamette Valley
Yes, the flat spot was already rolled over a bit and I rolled it an additional tooth and all seems good. Thanks for all the info.
So, basically, as long as you make that fat/wide spot disappear, it is aligned correctly, but don't over do it and go too far.
 

Forum statistics

Threads
138,037
Posts
1,997,577
Members
102,974
Latest member
kikeap
Back
Top