Fault Code 01027 - Next Step/s?

Recently bought a Foxwell NT510 (use it for Land Rover and 2009 Passat CC 2.0L TDI - has software for both vehicles loaded).

Anyway, yesterday and today noticed the glowplug amber light (wife descriptively calls it the "Curly Wurly" light) came on and started flashing, then of the course the EML amber light followed. At this stage no issues with power or anything else.

So, today I attached the Foxwell NT510 with the vehicle in the driveway and turned ignition on to read codes. The Foxwell showed "01027 exhaust gas recirculation circuit" as the only fault code present.

Interestingly, the first time the "Curly Wurly" light came on yesterday I stopped the car and turned off the engine and opened the bonnet to look for anything obvious - even though the engine was off I could hear a buzzing sound (like a bee or wasp) from under the engine cover; I don't know if this is linked?

So seems like this fault code may indicate a problem with the EGR vacuum solenoid?

Is anyone able to assist with this problem? Is this something I can easily check and fix myself?

Started the Passat CC (2009 2.0L TDI) yesterday and then turned off the ignition after 5 seconds - lifted the bonnet and again heard a buzzing from underneath the engine cover - it was definitely the solenoid buzzing. So, pulled out the solenoid - has stamped on it the part number 1K0906283A and also has "MADE IN USA" stamped on it.


Just one other thing, with a can of throttle body cleaner I assume it's a relatively easy job to remove the throttle body and EGR and clean with the throttle body cleaner - want to take my time and do a good job! Any comments? Anything to watch out for here? Do I need to "reset" the idle position with the Foxwell NT510 on the throttle body? What about EGR?

I assume cleaning the MAF with MAF cleaner is a piece of cake - have done it on other cars.

Can anyone direct me to written guides for the 2.0L TDI (2009 Passat CC)?

Checked the removed solenoid with a multimeter - has electrical continuity and shows a resistance of 37ohms from memory; of course, there could be a mechanical problem with the solenoid - spring or diaphragm? Anyway, after I re-assembled and went for a drive the "curly-wurly" light and the Engine Management Light have both gone. Have driven it several times now and the no warning lights have come on and driving just fine! Didn't replace the solenoid so not sure what the problem was??? I want to take off the throttle body and EGR valve and give them a good clean - I'm thinking this is reasonably easy? Will also clean the MAF, and the MAP if I can find it!

Any comments?

Will replace the N18 solenoid (relatively cheap) - looks like it is implicated in fault 01027? Fairly cheap, so no big loss if it's something else (sticking EGR, etc.?)?

Just one other thing, with a can of throttle body cleaner I assume it's a relatively easy job to remove the throttle body and EGR and clean with the throttle body cleaner - want to take my time and do a good job! Any comments? Anything to watch out for here? Do I need to "reset" the idle position with the Foxwell NT510 on the throttle body? What about EGR?

I assume cleaning the MAF with MAF cleaner is a piece of cake - have done it on other cars.

Can anyone direct me to written guides for the 2.0L TDI (2009 Passat CC) for throttle body and egr removal and clean? Any important things to watch out for?

I had the N75 (like N18, but for turbo) on my ALH start doing that buzzing thing - my best guess is that debris from a previous acutator failure contaminated it and caused it to not seal properly. I wasn't seeing drivability issues, but I replaced it anyway since it's not supposed to "sing" at you when you turn the car off. The new one doesn't do that.

Maybe with the N18 that would cause the EGR not to actuate as much as the ECU requests? Perhaps by pulling it out and turning it around you dislodged whatever was causing the buzzing, if it's not doing that any more.

Okay, buzzing returned and glow plug warning light and then EML warning light came on. Car still running fine but code 01027 showed up on the scanner again before disappearing once again. Reckon I'll bite the bullet and replace the buzzing solenoid.

Any ideas on pulling out the EGR and throttle body and cleaning them - should be relatively easy I presume? Are there guides somewhere, traps to watch out for?

Thank you for your feedback!

Since this is a TDI, you don't have a throttle body. Might you be referring to the anti shudder valve?

worm- What is the engine code? DT4?

It's a 2.0L TDI 125kW (Engine Code:CBB120323) - car is a 2009 Passat CC.

The vehicle just stopped on the road about six months ago out of the blue - suddenly! I thought it was the timing belt and had to get it towed to a VW Workshop. The workshop said the throttle body was badly clogged-up and the car just died due to air starvation. They cleaned it (not sure whether they removed and cleaned or cleaned in situ) and the car has run fine since then. They said I'd probably have to get the throttle body cleaned again in a year or so.

Can I clean the throttle body ("anti-shudder" valve) easily myself? What about the EGR valve? I know the MAF is easy.

tadawson said:

Since this is a TDI, you don't have a throttle body. Might you be referring to the anti shudder valve?

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VW mechanic said throttle body and also mentioned the EGR. What is the anti-shudder valve? As a novice when it comes to TDIs, I assumed there are two streams that go into the throttle body - one stream of fresh air from air filter and MAF and the other stream of recycled exhaust gases via the EGR?

So, maybe the anti-shudder valve suddenly stuck shut so no air got into the intake manifold and therfore the vehicle just suddenly shutdown (engine just went dead) suddenly when I was at a Stop sign. Anyway, the VW mechanic called it the throttle body, but I understand what you're saying, with a diesel it's actually an anti-shudder valve - maybe the Australian mechanics are a bit loose with their technical language?

Anyway, is it a fairly easy job to clean the anti-shudder and EGR valves by removing them from the vehicle and using throttle body cleaner?

A throttle body regulates airflow in a variable manner, and that does not happen in a diesel! The anti shudder valve closes fully on shutdown, and is open fully when running, with no intermediate positions. And yes, if it should fail closed, your engine will not run - after all, that's what it's there for!

And I can't speak for why your mechanic is using incorrect terms, unless he either a) doesn't have much TDI experience, and it's showing or b) he is dumbing things down in an attempt to be more readily understandable. All VW docs correctly call it an anti shudder valve . . . . (and the car will run fine without it . . . unlike a throttle body . . .).

Yeah, he definitely says throttle valve and has never mentioned ASV. Their workshop is full of VWs and Audis and they have been in business for 35 years and market themselves as VW and Audi specialists. Understand that the ASV is on/off (only really there to stop shudder when engine switched off) and the throttle valve is ranging. You are correct, he's either making a bad attempt at "simplifying things", is just lazy with his language or maybe ignorant? Anyway, I have to clean the ASV again and this time I want to remove it (and the EGR) myself and clean it myself.

Intestinalworm said:

Yeah, he definitely says throttle valve and has never mentioned ASV. Their workshop is full of VWs and Audis and they have been in business for 35 years and market themselves as VW and Audi specialists. Understand that the ASV is on/off (only really there to stop shudder when engine switched off) and the throttle valve is ranging. You are correct, he's either making a bad attempt at "simplifying things", is just lazy with his language or maybe ignorant? Anyway, I have to clean the ASV again and this time I want to remove it (and the EGR) myself and clean it myself.

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Unlikely to be ignorant in a shop you describe. Perhaps lazy in his language, but irrelevant if talking to someone who isn't knowledgeable. When you look at it, it does look a lot like a throttle body, and in some regards it is. If the butterfly closes the airflow is cut off. that sort of is what a throttle body does.

Yeah, loathe to pull him up on it - he did a good job installing a new clutch in the six speed DSG - something I couldn't do.

Anyway, going to pull out the ASV and EGR and clean thoroughly! Anything to look out for???