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-   -   CEL Light on Have Codes (https://volkswagenforum.com/forum/volkswagen-passat-cc-21/cel-light-have-codes-34147/)

mblanco2000 11-27-2011 06:32 PM

CEL Light on Have Codes
 
My check engine light came on this evening. Went over to the auto store and got them to pull the codes for me.

P0171
Definition: System too lean - bank 1 (Cylinder number 1 denotes bank 1)
Explanation: Low fuel pressure or volume
Probable cause: Faulty Ho2S (Heated oxygen sensor)
Large Vacuum leak
Faulty MAF Sensor

P0507
Definition: Idle Air control system RPM higher than expected
Explanation: Large Vacuum leak on engine
Probable cause: Throttle plate misadjusted or damaged
Faulty IAC valve

The idle is a touch rough when I am stopped. Also it seems when I am off the gas it does not decelerate as it normally does, the speed stays more constant.

In the past I think I had a bad O2 sensor, and would suspect that is the cause, but wanted to check w/ you guys before I buy parts. Help is appreciated, thanks.

Keithuk 11-28-2011 07:30 AM

VAG Error Code: 16555
EOBD II Error Code: P0171

Fault Location:
Fuel trim (FT), System too lean, bank 1

Possible Cause:
Intake/exhaust leak.
Secondary air injection (AIR) system.
Manifold absolute pressure (MAP) sensor (G71).
Mass air flow (MAF) sensor (G70).
Fuel pressure/pump.
Injector(s).
Evaporation emission (EVAP) canister purge valve.
Heated oxygen sensor (HO2S) (G39).

Possible Solutions:
In the vast majority of cases, simply cleaning the Mass air flow (MAF) sensor (G70) does the trick. It's best to take it off and spray it with electronics cleaner or brake cleaner. Inspect all vacuum and PCV hoses, replace if necessary. Check for a dirty fuel filter and proper fuel pressure.



VAG Error Code: 16891
EOBD II Error Code: P0507

Fault Location:
Idle speed control (ISC) system (G28) - rpm higher than expected

Possible Cause:
Throttle control unit.

As taken from my Free EODB II Error Codes Software

mblanco2000 11-28-2011 04:01 PM

How easy is it to change the fuel filter? I know I have never touched it yet. I believe it is in the gas tank.

Also what should I do about the 507 code? thanks

Keithuk 11-28-2011 07:13 PM

I can't tell you were the fuel filter is located but its not in the fuel top its probably under the car somewhere.

There is no 507 it should be a 4 digital number so


VAG Error Code: 16891
EOBD II Error Code: P0507

Fault Location:
Idle speed control (ISC) system (G28) - rpm higher than expected

Possible Cause:
Throttle control unit.

You really need to find someone with VAG-COM\VCDS to do an Autoscan and post the report in here?

mblanco2000 12-02-2011 08:09 AM

Well I cleaned the MAF sensor this morning. It is still idling a bit rough. Do you have to remove the plastic air cowling that holds the air filter to get to the TB to clean it? Is there a better way? I always have trouble removing that cowling....

Keithuk 12-02-2011 09:35 AM

I'm not sure on the petrol version but I can tell you how to check the MAF sensor on a TDI.

Testing/replacing the mk4 and newer (mk5 and mk6) MAF sensor on VW TDI engines

TDI engine TDI MAF/MAS (Mass air flow sensor) FAQ, for volkswagen TDI (diesel) 1996+

mblanco2000 12-02-2011 11:02 PM

Does anyone have a write up or information on getting to the Throttle Body on a Passat 2.0t? Mine is the 2007 model.

Thanks

Keithuk 12-03-2011 04:53 AM

1 Attachment(s)
Attachment 3324

How to : Clean your throttle body - uk-mkivs

taligentx.com: Passat - Throttle Body Cleaning

mblanco2000 12-05-2011 09:04 AM

Thanks for the link. That is great. However, on the 2007 2.0t Passat where is the throttle body? It looks like it might be against the firewall on the passenger side. Tough placement to get to. Let me know if I am wrong on this, I sure hope so.

Keithuk 12-05-2011 09:28 AM

Well I don't know where you live but I find the Haynes manuals very useful for doing DIY jobs an they are reasonably priced?

VW Passat Manuals

In fact I bought VW Golf & Jetta Petrol & Diesel (04 - 07) 53 to 07 which is the Mk5 Golf but alot of the things will be the same until that make a Mk6 Golf manual.


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