Throttle valve 2 for 3.0 V6 TDI

Hello everyone!

I've searched this forum but haven't found an answer, so I'm describing the problem. Occasionally, the yellow warning light comes on, and the well-known V6-TDI error code related to the intake manifold flap 2 is displayed. I've replaced the actuator motor, but the error still appears from time to time. Before I replace the entire intake manifold, I experimented with my workshop's diagnostic tool and found a function that allows you to test both flaps – they are moved back and forth alternately. This test works consistently for the intake manifold flap 1, meaning the target and actual values match, and the connecting rod moves smoothly up and down. However, for the intake manifold flap 2, it works a few times, and then suddenly, after restarting the engine, it stops working. The electric motor remains stuck in a high position (I believe around 89%) and no longer moves, even though the tester continues to fluctuate between around 23% and something around 80%. Now, one might say: the intake manifold or valve is stuck, so replace it... But: this also happens with the actuator motor removed and with the control rod completely disconnected from the valve. It seems to be an electrical problem and occurs identically with both the previously installed and the brand new actuator motor. It is not reproducible and seems to occur randomly. Is this a known issue, or can someone help me? The workshop now wants to start replacing the intake manifold, etc., which will probably cost a fortune and achieve nothing. Sure, here's the translation:

'Thank you for any advice in advance!'

Björn.

Touareg 3.0 V6 TDI 165 kW, model year 2007.

Hi,

I'm checking in again.
After 5 years with a 330d, I've now switched to an A4 with a BPP engine (2.7 TDI).
Year of manufacture: 09/2007; mileage: 142,000 km.

And as life often goes, of course, he immediately started complaining.

Same problem as bdsf2003.
Saurohr flap 2; sometimes it works, sometimes it doesn't. (tested via actuator diagnostics).
The valve is easy to operate. Sure, here's the translation:

"Also, please also mention an electrical fault."

@bdsf2003: Did you solve the problem? And how?

Are the "Steller" items available individually?
According to my AKTE system, it's only available as a complete unit with the intake manifold and valve for approximately 300 EUR.

Thank you very much for your help.

Regards,
Nick.

Okay, so if it's really the case that the motor isn't doing anything, but the valve is moving freely, I would first check if the signal is still reaching the servo motor. This eliminates a fault in the wiring, or it could indicate that the actuator motor is likely working correctly.

Okay, first, let's see if the signal still reaches that point even when the servo motor stops working.

Thank you for the tip.

That would also be my next choice.
Does anyone have circuit diagrams?
or the pinout of the 4-pin connector?

Regards,
Nick.

The information provided is without guarantee, but if I understand correctly, then...

Pin 1: Ground.
Pin 2: 12V+
Pins 3 and 4 are likely the control signal and the feedback signal indicating position, respectively.

I hope this helps you!

nickx wrote:

With the intake manifold flap 2, it works a few times, and then suddenly, after restarting the engine, it stops working again.

Is the error being set simultaneously?

Speculatively and without guarantee, I could imagine that the control value issued by the MSG is no longer actually changed once an error has been recorded.

The intake valve will open and close repeatedly until an error is detected. Then, while the diagnostic software will continue to cycle through its processes, the output will no longer change; instead, it will only display the default value due to the error that has been triggered.

A fault could potentially be introduced depending on the application, even if the feedback value deviates significantly for a short period. A classic example of this is potentiometers, where the resistive track can become dirty or otherwise interrupted. Whether that is actually possible with the throttle valve, or whether it is constructed in a completely different way, is beyond my knowledge.

Sure, here's the translation:

"It should definitely mean:"
A) I wouldn't be surprised if the diagnosis continues to appear as if it's being attempted, but nothing actually happens, especially if there was an error.
B) The actuator itself could be the problem, despite its ease of use and reliable operation, if its feedback signal is causing issues.

If possible, try moving the adjuster slowly by hand and see if the value jumps to a different reading at any point when viewed in VCDS.

Greetings.
Guste.

Okay, first of all, thank you all for your suggestions.
I tackled the issue yesterday.

The servo motors adjust the throttle valve flaps or limiters each time the ignition is turned on.
If you remove the connecting rods between the actuator and the valve, the error message "lower limit not reached" appears. The operator then lowers the device, fails to find the stop, and slowly retracts it.

The flaps do not have a sensor. MWB 36 and 37 do not show any change in actual values when the flaps are moved manually. Yes, when the actuator is moved manually.
Consequently, both the actuator and the sensor are integrated into the servo motor.

Question: How does the sensor measure the limit/stop? Current consumption? "Or no change in the actual value despite controlling the motor."

The angular range of the actuator is slightly larger than that of the flaps.
(To reattach the tie rod, you need to slightly deflect the adjuster.)

My theory:
When "ignition on" is selected, the control system engages the lower stop of the flaps.
He recognizes the attack through??? (see above).
Does this measurement point fall outside a tolerance range, for example, 90-100%, so that if it's, for example, 88%, an error message is displayed? It's possible that the flaps could be stuck (perhaps due to soot or other deposits).
Or, conversely: Even at 100% deflection, the limit has not been reached (This fits better with the error message).

What do you mean? How is the attack signaled? Is there another sensor for the valves?

I did not measure the signals.
I think that if there's a fault, the system will shut down because the operator won't know where the problem is; and even if they did, they wouldn't be able to fix it.
But, the V6-TDI engine has one important advantage:
On the other side of the counter, there are spare parts .
The actuators are the same. I exchanged them.
The error did not occur again.
I am observing that right now.

Regards,
Nick.

Quote:

If this measurement point falls outside a tolerance range, for example, 90 - 100%, such as at 88%, then an error message will appear. It's possible that the flaps could get stuck (a conceivable cause: EGR soot, etc.).

Possibly, as the actuator motor ages or wears out, the backlash in the gearbox increases, which can then cause the 88% value to be reached .

Hi,

After a few days of calm, things started up again on Friday.
Of course, starting with a long-distance trip right away, that's great...

When starting the engine, the warning light for the engine management system (EMS) remained on.
When does this light actually turn on?
My experience is that this error code has appeared in the error memory before, but the warning light didn't come on. The error is always reported as intermittent.

@vwSchrauber: Your theory seems to be correct:
However, the engine is actually unlikely to be the cause, as I swapped it with the one from the right bank.

According to that, it must be the valve mechanism that has too much play.

Does anyone have any other ideas?

I'm reluctant to buy parts for over 300 EUR, especially if it turns out to be nothing, like in the case of bdsf2003.


Regards,
Nick.

Unfortunately, I don't have a specific answer for your intake manifold control valve sensor. But I can answer your questions about the common interpretations of electronics.

nickx wrote:

The flaps do not have a sensor. MWB 36 and 37 do not show any change in the actual values when the flaps are moved manually. Yes, when the actuator is moved manually. According to the information, both the actuator and the sensor are located in the servo motor.

It would also be unusual to avoid this approach (double housings, double wiring, etc. --> costs), and it is primarily used in safety-critical assemblies.

nickx wrote:

Question: How does the sensor measure the limit? Current consumption? Or no actual value change despite activating the motor

.
Typically, power consumption is only evaluated when there is no actual value sensor present (e.g., in electric fuel pumps with automatic operation, like in a Golf 3). Once a sensor is present, the components typically used for current detection are usually omitted.

nickx wrote:

What do you mean? How is the attack signaled? Is there another sensor for the valves?

Unlikely. Most likely: Feedback from the actuator motor sensor. Possibly, also consider the amount of air being drawn in (if the valve is closed, the mass airflow sensor (MAF) value should decrease; otherwise, the valve may be defective).

nickx wrote:

The servo motors are the same. I exchanged them. The error did not occur again. I am observing that at the moment.

Let us know whether the fault has moved (e.g., defective servo motor) or remains stationary (e.g., intake manifold, wiring, MSG).

Hello Guste100,

The error is still "throttle valve 2", and it's a static error.

I've now found what I was looking for with the A6 enthusiasts and the MT community.

It's a very common problem with all 2.7 and 3.0 TDI engines, and the causes are:
1. Wear and tear in the mechanics of the first-generation servo motors.
2. Coking of the intake manifolds and flaps (often also accompanied by wear of the flap shaft).
3. Wear of the tie rods between the actuator motor and the valve shaft.

Engine replacement usually doesn't achieve much.
Cleaning the suction tubes was only partially successful (and a real pain).
The tie rods have been redesigned, but they are not available as individual parts.
A complete replacement (around 300-400 EUR for materials only) is a good solution, but it's expensive.

--> Prevent coking through standard measures.
1. Oil separators for gas lift systems.
2. AGR fitted with a 6mm aperture (illegal, included here for completeness only).

I will likely try custom-made, reinforced tie rods and perform the cleaning. I will update you with my progress. It probably will take a little while.

Here's where I need some advice again:
What should be considered when disassembling high-pressure pipelines?
Or, specifically, for commissioning? Ventilation?


Regards,
Nick.

nickx wrote:

This is a very well-known problem with all 2.7 and 3.0 TDIs, and the causes are: (...)

Interesting, thanks for the feedback!

nickx wrote:

I need some advice on this again: What should be considered when disassembling high-pressure pipelines? Or, specifically, for commissioning? Ventilation?

I'm not an expert on common rail systems, but on the AKF (8-cylinder common rail) engine I once worked on, simply bleeding the lines after assembly was sufficient (loosen the injector union nut, briefly start the engine, tighten the nuts on the injectors where diesel is coming out, etc.).
Attention: Use a rag, diesel is under very high pressure, and you don't want to inject it into yourself .

Greetings.
Guste.

Awesome!

Then it's a corporate issue.
Because older 16V R4 TDIs often suffer from swirl flap corrosion.

In those cases, the boost pressure is vented to the bypass valve (located between the intake manifold and the timing belt) – which is easy to spot if everything is covered in oil mist.

I only know it from the BMR (digital throttle valve via vacuum control valve (open/close)). I don't know how the CR-16V (with its stepper motor on the flaps) manages to do that.


m;

Typically, the lower ball joint of the tie rod is the one that wears out. To find a quick solution, you can try screwing a small 2-3mm screw into the ball joint. You might need to pre-drill a small hole, and then use the screw to tighten the head again, while still allowing for movement. That introduces a factor that leads to the error.

As a long-term solution, recreate a new tie rod with proper ball joints, similar to those used in model making, and that should solve the problem.

Quote:

2. AGR fitted with a 6mm aperture (illegal, included here for completeness only)

.

I would be surprised if that works without an error message.

Quote:

I'm not an expert on common rail systems, but on the AKF (8-cylinder common rail) that I once worked on, simply bleeding the lines after assembly was sufficient (loosen the injector union nut, briefly start the engine, and tighten the nuts on the injectors where diesel was coming out, etc.). Warning: Use a cloth. Diesel is under very high pressure, and you don't want to inject it into yourself. X

It can also work without bleeding - I've already started two completely empty rail lines before - it just takes a little longer.
Normally, simply opening a high-pressure line on the left cylinder bank will flush the air out of the system .

Quote:

Quote: 2. AGR fitted with a 6mm aperture (illegal, included here for completeness only). I would be surprised if that works without an error message.

That's why it's 6mm. Without sufficient flow, an error message appears. With a flow of 6mm (which is a reduced flow), it seems to work just barely without errors.
I haven't tried it myself, but this information comes from reports shared in other forums.

Apparently, someone completely removed it from there.

Thank you for the tip about bleeding the brakes.

I will keep you updated, but it will take some time...

Regards,
Nick.