2013 vw passat tdi start but die

I have 2013 vw passat tdi 6 speed that has around 140000 miles. while driving it die on me when I got it running again it would only run to 1100 rpm. I had to haul it home do to it had no power. i scanned to car and found four permanent code PO299 turbo underboost, PO104 mass air A (we had it unplug when try to start car) P2122 Pedal sensor D low and P2127 pedal sensor E low. i have replace the pedal and the battery. i have NO active code on the car. When you first start it the car will run for a few sec making you think it going to run then die. When you try to start it after that it hard to start and only fires. i have check fuel pumps i have 31 psi with key on when tank pump kick on goes to 68 psi. when you turn the car over the high pressure pump show 4000 + psi. Are my pump at normal start up or is the fuel shut off bad ??

Fuel Pressure info needed

Hello Everyone, I am Lonni's Uncle and I need some info to help him get his TDI running again. I do not have a VCDS but I have an Autel scanner that is showing a specified fuel pressure in the 4600 psi range (which has changed to over 5000 psi at times) and an actual fuel pressure when the engine is first started that pretty well mirrors the specified pressure, but as soon as the engine dies it drops to 31 psi within a few seconds.



My question is shouldn't the actual pressure remain higher than that?

If there is a check valve where is it located?



My only experience with diesel engines is a Cummins diesel and the actual pressure drops to about half the specified pressure when the engine is shut off.

There is a check valve/regulator on the HPFP N290, and one on the end of rail N276. Between the two, they keep the rail pressure/flow in the band the ECU is calling for. 4000lbs I think is common for idle ans should climb to 20-22,000 when load is applied and keep some sort of static pressure when shut off. Hopefully one of those sensors/wiring is bad, but there should be a code stored for either one.

One easy thing to check is the fuel filter, crack it open and see if you see metal flakes, that'd be a HPFP issue if you see metal, but seeing the that the car can idle and build 4,000lbs its a good sign.

When was the fuel filter change last? It's supposed to be every 20K which is conservative.

What's been the outside temps? and chance it could be gelled fuel?

As for the codes provided, as replacing the pedal and battery there are no codes stored? Doing a scan with VCDS may find something else that a generic scanner wont.

Best of luck.

Deleted

Thank you for responding 740GLE. The first thing we did was open and change the fuel filter (no metal shavings or any contaminants) which had been changed about 10k miles before this. The problem I had was he had disconnected the battery before I got there and all I had at that time was a cheap code reader( PO299 turbo underboost was the only code it showed) before we had hooked the Autel to it we had unplugged the pedal (because there was no pedal response) (naturally we broke the pedal checking it out and had to get a different pedal....LOL) We got it back home and hooked it up to the Autel which was able to read VW pids (64 pages worth) and the only other codes were ones we had created trying to diagnose the problem.

If you are saying after it starts that it should create between 20-22k psi with a load should it be reading that when you first get it started and before it dies a few seconds later? After the initial start it takes a long crank time to get it to fire the second time.
My second thought is if HPFP N290 or N276 was bad but a mechanical issue instead of a sensor fault would it throw a code?

UncleK said:

Thank you for responding 740GLE. The first thing we did was open and change the fuel filter (no metal shavings or any contaminants) which had been changed about 10k miles before this. The problem I had was he had disconnected the battery before I got there and all I had at that time was a cheap code reader( PO299 turbo underboost was the only code it showed) before we had hooked the Autel to it we had unplugged the pedal (because there was no pedal response) (naturally we broke the pedal checking it out and had to get a different pedal....LOL) We got it back home and hooked it up to the Autel which was able to read VW pids (64 pages worth) and the only other codes were ones we had created trying to diagnose the problem.

If you are saying after it starts that it should create between 20-22k psi with a load should it be reading that when you first get it started and before it dies a few seconds later? After the initial start it takes a long crank time to get it to fire the second time.
My second thought is if HPFP N290 or N276 was bad but a mechanical issue instead of a sensor fault would it throw a code?

Click to expand...

Good news on the fuel filter, least one less thing to worry about.

Correct if there is sometihng wrong with N290 or N276 I think a code would be stored, easy check, unplug one turn on ignition but not start see if a code is stored, the system check the ECU does each start up should pick up the connector isn't there.

PSI shouldn't be 20-22K until load and higher flow is needed by injectors, I'm not sure what the shut down retention PSI needs to be.

From the hard restart, sounds like something is wrong with the retention part of the fuel rail

740GLE, my next step is to unplug HPFP N290 and N276 to see if they will throw a code.
At least we are like minded on retention in the fuel rail.
Lonni has been over thinking the problem, but I keep going back to lack of fuel being the root cause of the problem.
If you let the car sit over night it will start when you crank it the first time and then have problems getting to fire after that.
I have an aversion to throwing parts at a car unless I can prove and verify the problem, so I am at an impasse right now on how to do that.
I am going to unplug the sensors, but I am 99% sure that it is going to throw a code (which doesn't give me the proof of what is wrong yet) when I do that.

I am still waiting on Lonni to get a pressure tester to see what I am getting from the pump in the tank and I have not figured out a way to test the pressure on the HPFP due to the high pressures that I will get from it.
From what I have seen (which is very little since it will not run long enough for me to really observe anything) is that once it builds up pressure and the specified pressure goes a little of 5k psi the actual psi starts to drop and it dies then the actual pressure drops like a rock. I have had the N290 sensor out and I do not see any thing but it being a sensor and no way for it to block off the fuel going back through the HPFP, I have not pulled the N276 sensor out yet, but I suspect it does not have a check valve there either since it just seems to be a place for a sensor and not a check valve.
My only other question at this point is will the PO299 turbo underboost code prevent it from starting. My thought is that it is a symptom of the problem and not the actual problem. When I try to use bidirectional controls it tell me that for safety reasons it can not run the test, which I figure is because the car is not running.
If you see anything wrong with my thought process please let me know.

I just got back from checking the sensors and unplugging them gave me a P019300 and a P009000. Plugged them back in and cleared codes. Engine codes show no faults now

My thoughts at this time is that there is something wrong with the fuel rail check valve leaking and not letting it build up enough pressure to let the engine continue running after the initial startup.
Question: how do I go about proving or disproving that assumption?

Parts swap? it could be failing just enough not to toss a code. Sensor should be cheap but I think it's not the cause of the issue.

You should be able to do output test of the in-tank pump to test it's output, VCDS can do it. It should be round 6bar, it is a new design for the Passat where as the previous CR had a tank pump and a tandem pump. If it's under 6 bar you may have found the problem, ie your HPFP is starved.

http://forums.tdiclub.com/showthread.php?t=465042&highlight=tank+pump

I checked pressure at the line on right side firewall where it comes from the tank to the fuel filter.
Turned key on and you hear the pump prime and shut off. Then you have to cycle the key to get it prime again.
Here is what I have come up with so far fuel pressure test is 60psi (4.13 bar)while pump is running,as soon as the pump turns off it drops to 40psi (2.75bar)and within 10 seconds it drops to 20psi (1.37bar) then drops back to zero in about a minute.
I had to use bidirectional controls on the Autel to make sure it was reaching max pressure the pump would put out ( due to the short cycle time with key on).
I am a real newbie (but wanting to learn) when it comes to these new high pressure fuel systems
Just my thoughts here, 60 psi should give me enough volume (considering that this car is getting almost 50 mpg to keep up with the HPFP to at least have it start and idle. If that is wrong can you explain why my thought process is leading me astray?
When the car broke down we did not have any problem restarting the car to put it on the trailer (the car was still warm at that time but since then temps have been hovering in the 30's and 40's and has never started again).
So is there criteria that the car is looking for and not finding it causing the ECU to shut down the injectors? If it is shutting down the injectors would it throw a code for that?
(The prior problem of no response from the pedal is still there. But I know the ECU is commanding the throttle body to 100% for the initial startup ( so it might not be returning control to the pedal)).
I have never seen a limp mode code set yet, so is there a way to force one so I can make sure the Autel can read that code in case it is there but the scanner is not seeing it. I know that ideally I should be using a VCDS but I have to work with what I have.

Okay, here is an update on testing the fuel pump in the tank. I clamped the hose off between the test gauge and the fuel filter and the pressure shot up to over a 100psi (6.9bar) (maxing my tester out)showing me that it is capable of creating the pressure I need.

So I am back to needing to know where the check valves are that contain that pressure in the system.

Going back over the system I noticed that there are connectors on each end of the fuel rail. Are they both sensors or check valve and sensors combined (they both threw codes when I unplugged them)?


Does anyone have a breakdown of the fuel system on a 2013 VW Passat with the 2.0 TDI?

it lists it as a video but its a PDF, somethings may have changed but it does have a good diagram of the fuel system of the NMS TDI

That being said, sounds like pressure is there but not sure what the flow is expected.

Thank you 740GLE it is not a complete breakdown for me but it does let me research all the components, which has led me to posts on this forum (Kudos to all the pros on here that went into such detail!) so I have my work cut out for me.

best of luck

Okay everyone
Here is where we are at the moment.
The P0299 code was the only code left to be checked out (still thinking it was a symptom and not the root cause) so we pulled the inlet side of the turbocharger and put a bore scope into it verifying all was fine on that side and assuming because the turbo was spinning all is good on the exhaust side.
Checking the fuel system out eliminated a fuel problem, but during the testing phase we heard an electric motor running (first time hearing that noise).

A big shout out to 740GLE for giving me the info causing me to cycle the key enough times causing the gear to finish stripping out while doing the fuel system checks and the forum members who had posted all the pictures of the anti shudder valves (who's names escape me since I had been through so many posts about this problem I lost track of who they were) giving me my aha moment!

It seemed to be coming from the underside of the motor, but breaking out the stethoscope narrowed it down to front side of motor (hearing the noise from underneath because of the ducting from turbo to front of engine) and everything clicked for me, 99% sure now. To cold to being laying under the car right now so waiting for a warm spell to be 100% sure. What threw us off was that we could start it up to get it on the trailer while the engine was still warm (it would only run at 1100 rpm but every little bit helped using the come-along to winch it on the trailer) but after it cooled off it was a no start.

It has to be what people are calling the anti-shudder valve (ASV) (Vacuum controlled) on the older style engines (not sure if it is called that on this engine because google search did not bring up one for the 2013 Passat 2.0 TDI (Electrically controlled) Anyone know another name for it on the new style TDI?

Here are my assumptions until I can prove it (I will post pictures after I get it pulled off the car to update this forum on what the new style engine looks like). It starts and dies the first time because the ASV flap has opened a little bit and when it fires up it sucks the flap closed causing it to die and all attempts after that to be futile.

No codes except the P0299 (caused by the ASV slamming almost shut when the gear stripped creating an underboost condition) no codes for ASV because it is a mechanical problem not an electrical problem.
P2122 Pedal sensor D low and P2127 pedal sensor E low because we automatically assumed that was root cause and unplugged it to check it out (No throttle body response because no matter how much pedal you gave it it couldn't suck any more air past the ASV flap).
More to come once we have the car fixed.

this sounds kinda similar to the dreaded P2015 code. The intake flap motor/encoder issue of the CEBA/CJAA. That system uses PWM to position the intake flaps and an encoder to know the position. It uses a mechanical stop point with a spring, the mechanical stop wears out and goes beyond what it shoud, the encoder goes from reading say 0 at closed to something like -358 or something, then you get a code. Luckily the CRKA doesn’t have those intake flap swirls so one less thing to figure out.

I wish I knew more about the ASV on the CRKA to help you out.