CEL came on yesterday, 2006 ODB trouble codes

[2006Tahoe2WD]

Right now this is a general question. The CEL came on yesterday (180,000 miles) and I plugged in my reader and found a whole bunch of P codes under drivetrain. A bunch of O2 sensor codes (bank 1,2 and pre and post cat) and a number of transmission codes. There were others but I thought those were the most interesting. At this point I erased the codes and will be checking to see how/if they reappear. Is this the right way to go about this? Next time I'll try to export the P code list and post here. Thanks.

 

[OR VietVet]

IMO, should have noted ALL the codes that initially came up. If you are not experiencing any drivability problems, then yes, clear codes and drive and see what comes back, if anything. If all these codes showed at the same time, I would suspect a ground problem. Any recent work? Live in a salt on the roads state?

You asked if is the right way to "go about this"? Should have noted all codes, if you didn't. You did not say.

 

[2006Tahoe2WD]

IMO, should have noted ALL the codes that initially came up. If you are not experiencing any drivability problems, then yes, clear codes and drive and see what comes back, if anything. If all these codes showed at the same time, I would suspect a ground problem. Any recent work? Live in a salt on the roads state?

You asked if is the right way to "go about this"? Should have noted all codes, if you didn't. You did not say.

You are right. I should have noted all the codes but it was a big list and I was lazy at the time. The drivability is good. I do plan to make note or download the list as I go. I expect some of the O2 codes to come back, I know I have an O2 sensor that is sort of weak. I had the feeling the codes accumulated over a long period of time. I'll check in about a week or so and report here. Thanks for the comments.

 

[2006Tahoe2WD]

Also, I'm thinking why not replace all 4 of the O2 sensors?
Is this difficult? Just buy the top of the line parts on RockAuto?

 

[OR VietVet]

Genuine GM, AC Delco or Delphi sensors. I would do all 4 at same time. Typically not hard but if live where salt on roads, your rust may impede your success. Lots of penetrant will be needed.

Why do you think the codes accumulated over a long period of time? have you had CEL on and just ignored? Right now, you are guessing and that is exactly what the codes are for, to keep from guessing. Unless of course you have been ignoring the CEL.

By the way, when it comes to repairs and maintenance, lazy costs money. See my signature.

 

[2006Tahoe2WD]

Genuine GM, AC Delco or Delphi sensors. I would do all 4 at same time. Typically not hard but if live where salt on roads, your rust may impede your success. Lots of penetrant will be needed.

Why do you think the codes accumulated over a long period of time? have you had CEL on and just ignored? Right now, you are guessing and that is exactly what the codes are for, to keep from guessing. Unless of course you have been ignoring the CEL.

By the way, when it comes to repairs and maintenance, lazy costs money. See my signature.

I know I know. The CEL just came on, I plugged in the reader the same day the CEL came on. This is why I don't think all the codes happened at the same time. Do I get at least some credit?

 

[OR VietVet]

Because the CEL came on only once, I think they all happened at the same time and likely did not happen over a period of time. That is why I guessed at a grounds problem. You did not answer my question. Live in a salt on the roads state? You say "Silicon Valley" in your member location but that is not always the truth. That is why I ask instead of assume.

Another unanswered question, Any recent work?

 

[strutaeng]

My guess is your money light will pop up again before anything else if you are daily driving the truck.

I usually don't like to delete codes if I'm troubleshooting because the only thing it does is, you wind up driving longer for the ECU to complete the drive cycles and checks. Unless I repaired/ replaced something or a known condition I may delete codes.

Write down the codes once they pop up again and go from there.

I've been having good luck with Denso O2 sensors from RockAuto BTW. Best prices I've found and pretty fast shipping. Not a sponsor, LoL.

 

[2006Tahoe2WD]

Because the CEL came on only once, I think they are happened at the same time and likely did not happen over a period of time. That is why I guessed at a grounds problem. You did not answer my question. Live in a salt on the roads state? You say "Silicon Valley" in your member location but that is not always the truth. That is why I ask instead of assume.

Another unanswered question, Any recent work?

As far as I know I haven't driven on roads with any salt for years or ever. I might have hit some salt when going over the Sonora Pass last summer. The latest work was install a new harmonic balancer.

 

[2006Tahoe2WD]

After clearing the codes I drove 15 miles with some freeway. I often select 3rd gear manually while driving on City streets.
Here are the codes I get. The O2 sensor codes did not reappear. The CEL did not come back on.

P Codes – 2006 Tahoe after 15 miles
P0442 Evap. Small leak
P0451 Fuel Tank Pressure Sensor Performance
P0454 Fuel Tank FTP sensor intermittent
P0464 Fuel Level Sensor (1) intermittent
P0567 Cruise Control Resume switch circuit
P0568 Cruise Control Set Switch Circuit
P0742 Torque Converter Clutch TCC system stuck on
P0751 1-2 Shift solenoid valve performance (no first/forth gear)
P0756 2-3 Shift solenoid valve performance (no first/second gear)
P0757 2-3 Shift solenoid valve performance (no third/forth gear)
P0894 Transmission component slipping
P1574 Stoplamp switch circuit

 

[strutaeng]

Oh, dang!

After clearing the codes I drove 15 miles with some freeway. I often select 3rd gear manually while driving on City streets.
Here are the codes I get. The O2 sensor codes did not reappear. The CEL did not come back on.

P Codes – 2006 Tahoe after 15 miles
P0442 Evap. Small leak
P0451 Fuel Tank Pressure Sensor Performance
P0454 Fuel Tank FTP sensor intermittent
P0464 Fuel Level Sensor (1) intermittent
P0567 Cruise Control Resume switch circuit
P0568 Cruise Control Set Switch Circuit
P0742 Torque Converter Clutch TCC system stuck on
P0751 1-2 Shift solenoid valve performance (no first/forth gear)
P0756 2-3 Shift solenoid valve performance (no first/second gear)
P0757 2-3 Shift solenoid valve performance (no third/forth gear)
P0894 Transmission component slipping
P1574 Stoplamp switch circuit

They don't call it "the money light" for nothing!

Thinking these are groups of issues: EVAP, fuel sender, and transmission. The stop lamp is probably related to transmission. Maybe as simple as brake light switch on the pedal?

Edit: I see your comment about the transmission...

 

[Doubeleive]

ouch, that's not going to be cheap
the largest chunk is going to be the transmission the rest is chump change
figure about $5k or so, slightly less if you can do some work yourself.
actually less if you are lucky and it's a 2wd you can grab a used transmission from a yard for around $1600 or so

 

[2006Tahoe2WD]

After some Googling/etc. a potential easy fix for the trans codes - there is a large electrical connector on the transmission. This might have worked its way out a bit and/or is being contaminated with trans fluid coming past the sealing O ring there.

 

[Fless]

The evap and fuel tank pressure codes are likely "pending" -- since the CEL isn't on yet -- and once they become active (after it fails the next time) it'll light up the money light. Expect it to happen after a full cold start.

 

[2006Tahoe2WD]

okay, good to know.

 

[Mudsport96]

If the rig is driving alright try to manually select gears 1-2-3-4 and see if you get shifts. There are too many transmission codes for it to not be shifting funny and you not notice it. So the plug on the trans is suspicious.

The CEL is most likely the evap codes as non-emission codes don't immediately trip the light.

 

[2006Tahoe2WD]

If the rig is driving alright try to manually select gears 1-2-3-4 and see if you get shifts. There are too many transmission codes for it to not be shifting funny and you not notice it. So the plug on the trans is suspicious.

The CEL is most likely the evap codes as non-emission codes don't immediately trip the light.

Thanks. Last night drove in manual gears 1,2,3. I'll double check and try all 4 gears today. The rig seems to be driving as well as it ever did. Shifting seems fine.

 

[2006Tahoe2WD]

Update. Went to my know good repair place. They sent me to the known good transmission place somewhat near me (San Jose). The guy there looked at the codes and said he is about 99% sure it is caused by a bad ignition module. He said there is a bulletin out on it.
I'm going to have one put in and see what happens.

 

[strutaeng]

After some Googling/etc. a potential easy fix for the trans codes - there is a large electrical connector on the transmission. This might have worked its way out a bit and/or is being contaminated with trans fluid coming past the sealing O ring there.

Yeah, definitely! Climb under there and do a quick visual. Remove the case plug and inspect for ATF fluid in there.

If suspect, drain the ATF, replace the filter, wiring harness and put new fluid. Opportunity to inspect the pan for any debris.

Update. Went to my know good repair place. They sent me to the known good transmission place somewhat near me (San Jose). The guy there looked at the codes and said he is about 99% sure it is caused by a bad ignition module. He said there is a bulletin out on it.
I'm going to have one put in and see what happens.

"Ignition module"? Huh? There's something called "ignition control module (ICM) on the previous generation of engine family, but the V8 LS engines don't have this.

I guess I was also going to say check your fuses to make something isn't blown, but let's hope whatever they change IS your issue.

 

[2006Tahoe2WD]

Yeah, definitely! Climb under there and do a quick visual. Remove the case plug and inspect for ATF fluid in there.

If suspect, drain the ATF, replace the filter, wiring harness and put new fluid. Opportunity to inspect the pan for any debris.

"Ignition module"? Huh? There's something called "ignition control module (ICM) on the previous generation of engine family, but the V8 LS engines don't have this.

I guess I was also going to say check your fuses to make something isn't blown, but let's hope whatever they change IS your issue.

Interesting..... I don't find any ignition module type parts in Rock Auto.