chevy silverado OBD2 codes

roser601

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#1
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MAKE: chevy
MODEL: silverado
YEAR: 2005
MILES: 155,000
ENGINE: 5,3
DESCRIBE ISSUE....had codes for throttle actuactor control module---cleared them with scan tool and after driving a few miles, codes for Mass volume airflow circuit A and System too lean Banks 1 & 2 popped up.
Are these codes all related to the Throttle Actuator Control being bad?
 
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kev2

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#2
post the codes -
Check pending codes also.
History helps, all you did was clear the throttle codes, no work, repairs mods, before these events ?
 

roser601

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OK' here goes---All I did was clear throttle codes after they popped up out of the clear blue sky!
I cleared them to see if they would repeat themselves. The second day after a few miles of driving I got a second set of different codes.
First Day: P2108 P1516 U0107--- cleared these codes

Second Day: P0101 P0171 P0174
What do ya'll think is the cause of these codes?
 

kev2

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#5
Vehicle is 100% STOCK ?

Any recent events - repairs, maintenance, dead battery?

Might want to check charging system - voltage , load and diodes.
 

roser601

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#6
Vehicle is stock except for headers that came with the truck when I bought it used 10 yrs ago.
I did have an issue last week when a spark plug wire popped off of one of the coils and the truck lost power and my display read "reduced engine power" and I pulled off of the road and discovered the problem and re-attached the spark plug wire and started the engine and the display warning cleared and the engine ran smoothly and all seemed OK until the engine light illuminated and the codes were set.
 

roser601

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Can anyone help me figure out what is causing the codes?
Any help will be greatly appreciated!
 

billr

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#8
Clear the codes and see what gets set new. Hopefully it won't be an entirely different assortment. Can you look at live-data? I haven't found U0107 yet, are you sure about that number?
 

roser601

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#9
Just had the chance to re-check the codes after clearing them the last time I posted.
3 codes were stored--P0101, P0171, P0174.
These are the same 3 codes as the last time.
What should I be looking for to correct the problem that is setting these codes?
 

billr

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#10
In live-data, look at MAF values. I think it would be worth cleaning the MAF sensor "screen", that may be all it needs.
 

kev2

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#11
MAF and lean codes -
What type of air filter - maybe a CAI ?
Check Vacuum hoses - PCV etc.
 

nickb2

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#12
For sure, these three codes are all TAC related and will also set a reduced engine power message in dash.

As for the other three codes that you got after clearing the TAC codes, it is quite normal to have lean codes on both banks if the MAF is not performing as it should.

Here is a chart to help diagnose that if cleaning the MAF doesn't do the trick.

See PDF ACE0
 

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nickb2

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#13
As for the TAC codes, I would wait to see if they come back before goofing around there. That part is quite expensive and not very serviceable for the non initiated.

The actuator is close to 400$, the TAC module is close to 250$. So close diagnosis of this system needs to be followed, as you may end up spending lots of money for nothing if you miss a diagnostic step.

If all wiring and voltage checks check out ok, you are looking at a few possible culprits. The TAC motor actuator, the TAC control module, and last but not least, the PCM. Usually, from experience, it is the TAC module that fries, it is next to the master and booster. Prime candidate for water intrusion.

Here is a chart for the U0107. See ACE1 pdf.
 

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roser601

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#14
I just cleaned the MAF sensor last nite.
Mine has no screen but I cleaned the wires with MAF cleaner and re-installed the MAF.
After starting the engine, I noticed an immediate improvement.
Idle is now smooth, there is no longer unburnt gas smell coming from exhaust and performance is back to normal.
I appreciate every response to my post and you guys have saved me a lot of time and money! Thanks again!
 

billr

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#15
Yes, by "screen" I meant whatever arrangement of sensing wire they have in there.