Glow Plug A3 1.6 TDI: Troubleshooting & Repair

Hello,

I'm having a problem with our A3 1.6 TDI, manufactured in 2000, with approximately 137,000 km on the odometer.

The filament starts to blink while driving.

Reading the error codes reveals the following:
Tuesday, December 11, 2018, 3:36:04:50641
VCDS version: RKS 17.8.0 running on Windows 7 x64.
http://shop.dieselschrauber.de

Address 01: Engine Control Module
Label file: DRV\03L-906-023-CAY.clb
Control unit part number: 03L 906 023 FC. Hardware: 03L 906 023 L.
Component and/or version: R4 1.6l TDI H23 9979.
Encoding: 00114016032400080000
Operating number: WSC 06314 000 00000
ASAM Dataset: EV_ECM16TDI02103L906023FC 003016 (AU35)
ROD: EV_ECM16TDI02103L906023AQ_003.rod
VCID: 6CD1FB0C874E262646-8038
2 error codes found:

7330 - Air mass meter (G70)
P0101 00 [167] - Implausible signal.
Warning light ON - unconfirmed - checked since last reset.
Environmental conditions:
Error status: 00000001
Error priority: 2
Error frequency: 5
Mileage: 134,597 km
Date: 2018.11.24
Time: 01:30:42

Motor speed: 1671.50 rpm.
Normalized load value: 0.0%
Vehicle speed: 66 km/h
Coolant temperature: 90 °C.
Intake air temperature: 11 °C
Atmospheric pressure: 980 millibars.
Voltage at terminal 30: 14.795 V.
Lost learning counter via OBD: 40.
Air mass: Actual value (mg/stroke) - MAF_MEAS: 614.861 mg/stroke.
Air mass ratio, filtered - FAC_MAF_CYL_KGH_RATIO_FIL: 0.84448
Exhaust gas recirculation valve: Actual value - ANG_EGRV[0]: 0.000 %.
Throttle valve actuator: Actual value - ANG_THR[0]: 95.868 %
Boost pressure: Target value - MAP_SP_MMV: 1200.65 hPa.
Boost pressure: Actual value - MAP_MMV: 1200.65 hPa.
Motor torque - TQI_SP: 0.00 Nm

7338 - Air leak in the intake system.
P2279 00 [032] - -
Sporadic - unconfirmed - checked since last deletion.
Environmental conditions:
Error status: 00000001
Error priority: 2
Error frequency: 1.
Mileage: 134,372 km
Date: 2018.11.22
Time: 17:54:43

Motor speed: 1749.00 rpm.
Nominal load: 100.0%.
Vehicle speed: 69 km/h
Coolant temperature: 27 °C
Intake air temperature: 3 °C
Atmospheric pressure: 940 mbar.
Voltage at terminal 30: 14.231 V.
Lost learning counter via OBD: 38
Air mass: Actual value (mg/stroke) - MAF_MEAS: 1290.74 mg/stroke.
Air mass ratio, filtered - FAC_MAF_CYL_KGH_RATIO_FIL: 1.00000
Exhaust gas recirculation valve: Actual value - ANG_EGRV[0]: 0.000 %.
Throttle valve actuator: Actual value - ANG_THR[0]: 95.996 %
Boost pressure: Target value - MAP_SP_MMV: 2291.92 hPa.
Boost pressure: Actual value - MAP_MMV: 2014.32 hPa.
Motor torque - TQI_SP: 259.97 Nm

I also used to monitor the differential pressure. At full throttle (4000 RPM), it reached values of 230 mBar.

The car feels like it's being held back. That's my impression, but I normally drive a 3.0 TDI as well.

I suspect the DPF is the problem, but the oil ash content is 35g, which is quite high.

What can I do? Should I install a new LMM (lambda sensor module)?

Thank you for your help.

Best regards, Chris.

"My car also displayed the error message about the implausible signal when I installed a diode instead of the mass airflow sensor (MAF). However, the power was fully available from around 2500 RPM onwards because the airflow was approximately correct at that point. The engine only lacked power in the lower RPM range."

If I were you, I would first visually inspect the intercooler system. You might already spot something. If you don't see anything, quickly press your ear against it; you might then hear any air leaks. It's cheaper than randomly replacing a new mass airflow sensor.

Best regards, Tobias.

Thanks, Tobias! So, was that a defective mass airflow sensor in your case?

How can I test the mass airflow sensor (MAF) using VCDS?

Best regards, Chris.

Hello,

Quote:

7338 - Air leak in the intake system. P2279 00 [032] - - ... Motor speed: 1749.00 rpm. ... Atmospheric pressure: 940 millibars. ... Air mass: Actual value (mg/stroke) - MAF_MEAS: 1290.74 mg/stroke

It's quite likely that the engine control unit has wonderfully identified the cause.
Vacuum leak in the intake system

Why don't you check if the intercooler piping is airtight? If you were to install a diode instead of the MAF sensor, which, by the way, would be completely ridiculous, you wouldn't have to ask about the cause of the problem, would you?

Best regards, Rainer.

Thank you, Rainer.
So, the thing with the diode was done by Tobias.

I'm only surprised that the air leak error occurred sporadically and was only confirmed once, while the mass airflow sensor (MAF) error occurred 5 times.

Furthermore, I unfortunately do not have a tool for removing the charge air cooler .

Best regards, Chris.

ch914er wrote:

Thank you, Rainer. So, the thing with the diode was done by Tobias. I'm only surprised that the air leak error occurred sporadically and was only confirmed once, while the mass airflow sensor (MAF) error occurred 5 times. Furthermore, I unfortunately do not have a tool for removing the charge air cooler . Best regards, Chris

It's usually recognizable due to oil leakage...

Thanks, I just checked everything, but I didn't see anything.
Unfortunately, I couldn't get a good view of the intercooler .

For creating a vacuum, the hose to the throttle valve is a good option. However, on the other side , I can seal it near the mass airflow sensor, or should it be before the turbo?
Best regards, Chris.

You can make your own "tool" for pressing the valve stem. For example, you could use a round lid or a piece of wood: round, in the right size, with a bicycle valve stem or similar in the center. But then you'll have peace of mind.

Okay, so I installed a new LMM (likely referring to a mass airflow sensor) today and took it for a test drive. Everything seemed okay at first, but then, when I was accelerating, the check engine light came on again.

With just one mistake:
"One error found:"
7330 - Air Mass Meter (G70) P0101 00 [101] - Implausible signal unconfirmed - checked since last clearing
Environmental conditions:
Error status: 00000001
Error priority: 2
Error frequency: 1
Mileage: 134637 km
Date: 2018.12.13
Time: 16:28:08
text
Engine speed: 1248.00 /min
Normalized load value: 0.0 %
Vehicle speed: 64 km/h
Coolant temperature: 92 °C
Intake air temperature: 3 °C
Ambient air pressure: 970 mbar
Voltage at terminal 30: 14.682 V
Number of lost cycles according to OBD: 40
Air mass: Actual value (mg/stroke) - MAF_MES: 625.882 mg/stroke
Air mass ratio filtered - FAC_MAF_CYL_KGH_RATIO_FIL: 0.83698
Exhaust gas recirculation valve: Actual value - ANG_EGRV[0]: -0.189 %
Throttle valve actuator: Actual value - ANG_THR[0]: 95.996 %
Boost pressure: Target value - MAP_SP_MMV: 1190.78 hPa
Boost pressure: Actual value - MAP_MMV: 1190.78 hPa
Engine torque - TQI_SP: 0.00 Nm

What surprises me is the following: Exhaust gas recirculation valve: Actual value - EGRV[0]: -0.189 %.
because, in fact, the EGR system was specifically deactivated.

In the old error messages, the percentage was always 0.000%.

Now I'm concerned that the EGR valve might have already had a defect.
I saw this in a video from "AutoDoc," and in that case, the valve wasn't closing completely.
Then I read all the values using the EGR valve (see picture).

I'm going to try and drive the AGR track tomorrow.
Just talk about the throttle valve; if the valve is closed properly, the pressure should be maintained.

Any other ideas?

VG Chris.

Oh, wonderful...

It's difficult to help if you don't explain what has been done.

Okay, let me summarize: The vehicle has a problem in the area of the intercooler system.


You're getting some answers. Several posts later, it says: The AGR valve has been "deactivated" or "disabled"...?


If you're expecting help, simply tell the person who's going to help you beforehand what it's about. That's helpful and, incidentally, quite friendly.

So, the error was already there before.
Furthermore, I wasn't sure if anyone would actually respond, and I thought a response like, "That's illegal, and now figure out how to deal with it," might come .

I just thought it might be related to the great Audi update, so I had the AGR system deactivated.

Unfortunately, the error reappeared after that.

Following that, the mass airflow sensor (MAF sensor) was replaced.

During the first test drive with the new mass airflow sensor, the error reappeared, as mentioned in my post from yesterday, but it was different this time.

During today's trip, no errors occurred.

I think we should make the topic .

Thank you, Chris.

I also think...
Generally, it's always best to describe all the relevant conditions and requirements to anyone you're asking for help. This way, people can avoid wasting their time and effort.

In case of any fault, the following general steps should be taken: restore the system to its original state, check all components for leaks, verify that all connectors are securely seated and free from moisture, and inspect the cable harness for any potential friction points.

When sensor errors appear intermittently, experience suggests that the probability of a fault being on the electrical side is slightly higher than on the mechanical side, although this is not always the case.

Sorry, I have to ask again, maybe someone has an idea .

So, it's the EGR valve, and the valve is no longer closing completely (I've checked it for leaks).

Following that, I blocked the intake manifold opening from the EGR valve.

Now, it also has more power again.

Unfortunately, I'm still experiencing the issue with LMM.
Although I've already replaced this one before.
Switching back to the old version resulted in a higher number of errors, while with the new LMM, the errors only occur occasionally.

Important: The error only occurs when the system is under heavy load.
Now and then.
Exhaust gas recirculation valve: Actual value - ANG_EGRV[0]: 0.000 %.
Exhaust gas recirculation valve: Actual value - ANG_EGRV[0]: -0.189 %.

How could I trick the engine control unit (ECU) into thinking that the EGR valve is closed?
Does anyone have the pinout diagram for the AGR valve?

Thank you very much.
Chris.

Please ensure your vehicle is in proper working order. You will not receive any advice or instructions here regarding illegal activities.

Quote:

Does anyone have the pinout diagram for the AGR valve?

See Erwin.