# Please Help, New to VW (2010 Jetta 2.5L)



## Wants_to_fast_but_cant (Mar 13, 2015)

I have 4 codes, I wish to tackle one at a time....
So I had my O2 sensor replaced about 2 weeks ago and I have a P2626 code that pops up. Any idea what it could be and how I can fix it? I have been looking everywhere for answers so some help would be awesome!  Thanks in advance


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## Matti von Kessing (Jan 17, 2011)

Wants_to_fast_but_cant said:


> I have 4 codes, I wish to tackle one at a time....
> So I had my O2 sensor replaced about 2 weeks ago and I have a P2626 code that pops up. Any idea what it could be and how I can fix it? I have been looking everywhere for answers so some help would be awesome!  Thanks in advance


Post all 4 now, and we'll tackle them 1 at a time. Seemingly un-related codes, together, can be an indication of something else. For example, on the FSI/TSI, when the throttle body wiring harness becomes an issue on some cars, the ECU throws codes that say individual sensors (throttle position etc.) need to be replaced. If you go through the trouble of trying to resolve the individual codes without looking at the big picture, you're going to spend a lot of money unnecessarily replacing sensors. Where did you get your codes from? If you can, find somebody local to do a VCDS scan for you. It will give us a lot more information. If you have a VCDS print-out, post it. 

As for your current question a P2626: the Bentley description is "O2 Sensor Pumping Current Trim Circuit Open B1S1"

Lets check simple things first: check if the new sensor got plugged in when it was installed. What initiated the replacement of the O2 sensor in the first place?


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## Wants_to_fast_but_cant (Mar 13, 2015)

The 02sensor was replaced because of a code. that's about all I know. I took it to a VW specialist, so he charged me like 300 bucks in all. that's why I'm resorting to doing everything myself. the other codes are po413 p2257 p2401. I remember the specialist told me that I needed to replace a solenoid. not a starter one, I'm new too all this mechanical stuff. I fix airplanes not cars haha :banghead:


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## Matti von Kessing (Jan 17, 2011)

P2626	O2 Sensor Pumping Current Trim Circuit Open B1S1
P0413	SAI System Switching Valve A Circuit Open
P2257	SAI System Control A Circuit Low
P2401	Evap Emission System Leak Detection Pump Control Circuit Low

There are you codes. While it is possible, I highly doubt that all of those sensors are going to fail simultaneously. 2.5L engine wiring diagrams start at EWD-205 in my Rabbit Bentley manual. I'm finding each of those sensors in the wiring diagrams, then trying to trace them back to common points of failure. They all connect to the Engine Control Module (but really, what doesn't. It's a friggin 121 pin connector). 

Oxygen sensor uses pins 51, 52, 70, 71, and 5, and is connected through a 6-pin connector on the firewall. There doesn't appear to be an actual circuit link to the others.
Secondary Air Injection Valve uses pin 121, and is also connected to the SAI relay. You could check fuse SB23 in fuse panel B.
Leak detection pump uses pins 25 and 80, and is also connected to the SAI relay via the same connection as the SAI Valve.

My first action, check that fuse. Check connections to that relay. A question for somebody that knows more than me: do problems with the SAI system cause the O2 sensor fuel trim circuit to open by default?


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## Wants_to_fast_but_cant (Mar 13, 2015)

Well one thing I was told is since my vehicle is modded; turbo, intake, etc. the smog pump or something like that was removed. so I need to delete that. the problem is that the shop that did the tune is United Motorsports in Connecticut. I live in Washington State. my air to fuel ratio also is good more the 2/3 of the time I drive it and then it spikes but comes back to normal. and I feel my car losing power for a second. its actually died on my a couple of times in idle. I rev the engine mildly and the rpms drop far below 1 and it just dies. im not to much help I know but maybe this bit of information can help some else find the root problem. I tried getting advise from the guy that replaced my 02 sensor but no luck on him giving me an answer. You have actually been helping a lot. Thankyou


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## Matti von Kessing (Jan 17, 2011)

Wants_to_fast_but_cant said:


> Well one thing I was told is since my vehicle is modded; turbo, intake, etc. the smog pump or something like that was removed. so I need to delete that. the problem is that the shop that did the tune is United Motorsports in Connecticut. I live in Washington State. my air to fuel ratio also is good more the 2/3 of the time I drive it and then it spikes but comes back to normal. and I feel my car losing power for a second. its actually died on my a couple of times in idle. I rev the engine mildly and the rpms drop far below 1 and it just dies. im not to much help I know but maybe this bit of information can help some else find the root problem. I tried getting advise from the guy that replaced my 02 sensor but no luck on him giving me an answer. You have actually been helping a lot. Thankyou


This info seems pretty relevant. Honestly, going off of OBDII codes, you're just going to end up needlessly replacing a lot of parts. Find somebody local with a VCDS. Run a scan. Do some datalogging and replicate your A/F problem. Or find a new mechanic that will actually troubleshoot, and not just throw parts at it. 

Questions: 
How are you monitoring A/F?
What exactly is a "spike?" Does it spike lean? does it spike rich?
What operating conditions does the spike happen?


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## Wants_to_fast_but_cant (Mar 13, 2015)

I am Monitoring A/F by gauge when it runs smoothly its at 11-14 but when I lose power I feel it and the gauge runs super lean. the gauge dashes out. its hit 17 and 18 the dashes out,
And when it spikes is when I am around 2500RPM or when I let off the gas at times. it spikes. not always but half the time it will dash out
I feel like I read somewhere that it might be a sensor. Its like a cable of some wort. I saw a thread about this same symptom


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## Wants_to_fast_but_cant (Mar 13, 2015)

http://www.autospeed.com/cms/article.html?&A=1595
is this link accurate?


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