TDI CAYE: LMM Error After Replacement - Low Power

Hello everyone,

I'm no longer happy with my 75 hp 1.6L TDI CAYE Caddy after the software update from VW.

After a happy 85,000 km, the forced software update happened, and I ended up spending €3,600 on a new EGR valve, oxygen sensors, a new DPF, etc.

I don't want to go to Zum Freudlichen anymore!

Since the car is showing very little power, feeling like only 50 horsepower, and has a fuel consumption of 7-8 liters, and there were no error codes stored in the engine control unit (ECU), I decided to replace the mass airflow sensor (MAF) myself with a new, genuine Continental MAF sensor.

The replacement didn't make a difference; instead, the fault light is now constantly on, displaying the following error code:

7329 - Air mass sensor (G70)
P0101 00 [167] - Implausible signal.

Please find the log attached.

I would really appreciate it if someone could give me a tip on how to narrow down the source of the error.

Greetings, druese.

Hi,

This is not a log. Please record the desired air mass, the actual air mass, and the engine speed in the extended measurement blocks.

See also:
I am unable to access external URLs, so I cannot translate the text from the provided link. Please provide the text directly, and I will be happy to translate it for you.

Best regards, Rainer.

Hello Rainer,

Thank you for your reply. Here is the correct "log" you requested.

If you need me to log anything else or require further information, I will take care of it as quickly as possible.

You're welcome.

The actual value and target value of the air mass are logged in different units; please log both values again in mg/H.

Best regards, Rainer.

Sorry, beginner's mistake...

Here, only third gear, full throttle, from 1000 RPM to 4000 RPM.

Greetings, friend.

Hello,

"The logs show drops in performance, and besides that, the values at full throttle are below the target values. I'm not sure if this is normal for 1.6 TDIs, but at full throttle, the actual values should ideally be above the target values."
It's possible that the emissions update is also a factor here.

LMM is 100% sure to be the right choice and comes from the instead of a parts source that sells printed cartons on demand?
In the past, especially with LMM (likely referring to a specific product or company), it was common for people to be scammed and sold items that were essentially scrap metal (more or less functional LMM knock-offs).

Regarding the decreasing values: I would like to examine the LMM wiring, millimeter by millimeter, to check for any damage or cable breaks.
Don't forget to wiggle the plugs.
You can also let the engine idle and try to trigger the sensor errors by bending or wiggling the connectors and cables.

Another possible, albeit unpleasant, cause could be a faulty EGR valve or a defective throttle valve. However, before investigating further, I would definitely make sure that the connectors, wiring, and mass airflow sensor (MAF) are all in good condition.

Best regards, Rainer.

Just checked again, and if the mileage hasn't been tampered with, it's probably too low to be causing problems with the EGR valve and/or the throttle body...

Quote:

Mileage: 88943 km

In principle, worn plastic gears could also be the cause of the fluctuating air mass readings in your system, even if the actuators look different in your case (pictures are welcome).
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

Best regards, Rainer.

Thank you for the data analysis; I was just looking at it myself using KDatascope.

Here's some information about the new LMM, including a picture. It was purchased directly from the parts counter.

The actual mileage is 89,000 km.

The AGR valve is almost new, with approximately 4000 km driven. It was replaced by VW because it failed after only 2 km of driving following an update.

The new DPF/catalytic converter has only been installed for 4000 km because the old one was completely empty. Could there still be some residue stuck in the muffler?

Greetings, friend.

I will definitely check the cable connection to the mass airflow sensor tomorrow and verify the values.

Greetings, friend.

Quote:

The new DPF/catalytic converter has also only been installed for 4000 km, because the old one was EMPTY, could it be that there is still some residue stuck in the muffler?

Unfortunately, this is quite possible, and it can significantly hinder the airflow of air masses, depending on the specific situation and the flexibility of the structure.

PS: Quite a few problems for the mileage. Did you buy the car new?

Hello,

Unfortunately, I was unable to trigger a cable fault, so I will disconnect the exhaust pipe after the DPF-catalytic converter and drive a short distance without the muffler.

I bought the Caddy as a new car and had no problems until the update.

I've set myself a deadline: if I don't get the Caddy "finished" by the end of July, I'll get a Peugeot Partner with a gasoline engine.

Greetings, druese.