LMM 038 906 461: Replacement for 06A 906 461

Hello,

After a long time, I have a question again: In my Golf IV Variant, manufactured in 2000 with an ALH engine, the mass airflow sensor (MAF) was defective. The original MAF sensor, which is now defective, had the VW part number 06A 906 461.

I then obtained a LMM (mass airflow sensor) with part number 038 906 461 through an acquaintance for testing. According to the parts list, this part was only installed in vehicles manufactured from 2002 onwards (and I believe only in PD engines, which I have in my 90hp TDI). The test was successful; the car ran like new again, with the performance and responsiveness as if it were the first day.

I then bought a 'like-new' 06A 906 461 (which is the same part number as the original) on eBay, but I had the problem that it seemed to have aged a bit. It ran reasonably well, but the engine's response was poor, and the performance above 3000 RPM wasn't great either.

I then spoke to the aforementioned acquaintance again, and he said I could have the 038 906 461 if I wanted. Since the car performs exceptionally well with this 038 mass airflow sensor (better than ever before), I'm wondering if this mass airflow sensor actually has the same characteristics or if the characteristics may have been altered. If that's the case, it could have almost the same effect as the well-known diode replacement, with the corresponding disadvantages. That's why I'm asking: Does anyone know if the 038 906 461 has the same characteristics as the 06A 906 461 and can therefore be used without any issues? How can I determine this, or is there a datasheet available for it?

I would be very grateful for any tips.

Best regards, Klaus.

Quote:

How can I determine that

Just record a few typical driving maneuvers.

For example, accelerate from 1000 RPM on a flat surface with full throttle.

m;

dieselmartin wrote:

Just record a few typical driving maneuvers. Accelerate from 1000 RPM on a flat surface, using full throttle.

... right, and that's up to approximately 4500 rpm.

Make sure to log the limits (e.g., Maximum Working Pressure 8, and preferably also the Load Drop, Maximum Working Pressure 10 or 11).
General rule: With an OEM mass airflow sensor (MAF), the fuel trim will be approximately 2-4 mg above the baseline once full boost pressure is achieved (depending on the engine model, all without tuning).

If the "fire department" lambda sensor (LMM) reports an excessive amount of air well before reaching full boost pressure, you likely have a faulty sensor. To diagnose this, log data in various driving conditions, including low RPM and full throttle, to capture as many data points as possible.