Connector assignment: Charging pressure/Charging air temperature sensor in ASV

Hello!

Does anyone know the wiring diagram for the boost sensor on the hose that connects to the air-water cooler and goes away from the intake manifold? There, to my knowledge, the intake air temperature and the boost pressure are reduced.

I would like to replace the intake air temperature sensor with a fixed resistor, which might simulate approximately 50°C. With this, I believe I have been able to address the extremely sluggish response of my TDI engine and the approximately 0.3-0.4 seconds lower torque values at 30°C ambient temperature compared to 10°C ambient temperature in the Ulf test.

Has anyone ever thought about changing the signal from the LMM so that it provides approximately 20% higher values? This could also help to achieve a quicker response time (although there might be a slight delay with the throttle at the beginning of acceleration).

Best regards, Georg

Hello Georg,

The pinout of the combined air/fuel pressure and air temperature sensor can be checked by me at home, if someone from the forum doesn't get there faster.
You can also find the pinout yourself using a multimeter by measuring the connector when the ignition is on (Caution: This will most likely result in an error entry).
Here are the potential areas to explore:
- Mass
- +5V (Power supply for charging pressure sensor)
- Ausgang voltage of the pressure sensor, at atmospheric pressure of 1.8V at 2.5bar output
- Messpin Charge Air Temperature Sensor, can be easily identified by warming it manually and measuring its resistance against a ground, resistance change.

Hello, Rainer

Hello Rainer,

Thank you for the response, I'll experiment soon.

In an American TDI forum, I found a very interesting thread about the LMM:

http://forums.tdiclub.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=4&t=003598&p=

If someone is interested but not very proficient in English, I am happy to translate the statements in a meaningful way.

Best regards, Georg

Yes, I have read the article and it seems helpful. I will try it with my PD 100 PS engine!

What do you think? Does it bring about an improvement in performance compared to the standard LMM?

No, on the contrary, he also writes that it is only a means to get home in an emergency, not to achieve extra performance. More low performance and more fuel consumption.

Best regards,

Jan

Okay, I've noticed that it's only intended as a replacement for his old LMM.
However, while I was browsing the forum, I often came across MAF 2.0, which is equivalent to LMM 2.0. Some people in this forum have this mass airflow sensor. What does this mean? Does the LMM provide more accurate readings than the one from VW?

Hi Georg

Quote:

Has anyone ever thought about changing the signal from the LMM so that it provides approximately 20% higher values? This could also help to achieve a quicker response time (although there might be a slight increase in "Russ" at the beginning of acceleration).

I've done the 2000 - 4000 test with adjustable boost pressure.
(When the Powerbox is active, the charging pressure is also significantly increased, even when the full load contact is reached).

When the power box is disconnected, the only remaining function when the switch is in the "on" position is to increase the charging pressure.

With a 5% increase in real air mass flow rate due to the higher pressure, I expected a correspondingly "significant" reduction in the transit time of at least 0.2 sec.

Several measurements with normal and increased pressure did not result in a reduction in time, which could indicate improved performance.

The attempt with the manipulated air temperature signal is still pending for me...

Hello,

Here is the pinout of the boost pressure sensor with a 4-pin connector:

- Pin 1: Ground (0 V)
- Pin 2: Connection for NTC air temperature sensor from the control unit
- Pin 3 +5V power supply for the charging pressure sensor
- Pin 4 Output Signal (Voltage) Load Sensor

Therefore, the intake air temperature is measured between pin 1 and 2, and the output signal of the boost pressure sensor is measured between pin 1 and 4.
Regarding load cell sensors, there are models available with different measurement ranges.
In my AHF (110PS TDI), the specification is for 250kPa (~2.5bar).
The output voltage of the pressure sensor is linear between 20kPa (0.4 V) and 250kPa (4.65 V).
2.5 bar absolute pressure corresponds to approximately 1.5 bar of boost pressure, as the normal air pressure is being measured. D.h. when the ignition is on but the engine is stationary, a voltage is supplied that corresponds to approximately 1 bar absolute, or about 1.8V, if I remember correctly.

Hello, Rainer

Hello Rainer,

NTC = Negative Temperature Coefficient (in °C)?

Does that mean I would need to reduce the resistance in order to simulate a lower temperature? Or increase?

For the load cell sensor, I need to incorporate a voltage divider or a diode that creates the appropriate voltage drop. Does anyone know the specifications for some diodes? According to my data, 0.1 bar corresponds to approximately 0.19 volts.
I will check it with a multimeter on my outlet.

Best regards, Georg

Hi Georg

To simulate a higher temperature, you need to connect a resistor in parallel with the NTC. The effect is significantly greater at low temperatures than at high temperatures.

To simulate a lower temperature, you need to connect a resistor in series with the NTC. The effect is significantly greater at lower real temperatures than at higher real temperatures.

220 Ohm result in real 80° approximately 65°, from 50° approximately 40°, but from 10° only just 9°C.
330 Ohms result in a real 80° angle approximately 55°.

Hello Ulf,

Some time ago, I replaced the air intake temperature sensor with a fixed resistor.
The diagnostic device indicated a coolant intake temperature of 17°C. In comparison to the standard (30°C - 50°C), no change in performance was observed. Subjectively, the driving feel seemed a bit 'rough'.

Hello, Rainer

Ulf, thank you very much for the values.

Quote: To simulate a lower temperature, you must connect a resistor in series with the NTC. The effect is significantly greater at lower real temperatures than at higher real temperatures.
End of Quote

{QUESTION}
To simulate a lower temperature, you need to connect a resistor in series with the NTC. The effect is significantly greater at higher real temperatures than at lower real temperatures.
?

I think I'll probably go back to using the fixed resistor instead of the one connected in series. Do you or Rainer perhaps have a suitable value for a pleasant simulated room temperature right now?

To get started, I want to buy a female/male adapter from a friendly VW dealer on Monday and use it as an intermediate piece. With an old analog multimeter, I also want to measure the charging pressure. (This device has a 0..5V scale and is therefore quite suitable.)

Best regards, Georg

Hello Georg, I forgot the resistance value, but could you just measure it at 20°C?
To display the charging pressure using an analog multimeter, I would be cautious if the output resistance of the charging pressure sensor is too high for your multimeter (or vice versa), as this could result in uncontrolled charging pressure increases with simultaneous false readings on the multimeter.
So, teste also zuerst mit einem zusätzlichen Multimeter oder Widerstand, ob die Ausgangsspannung des Lade-Sensors unter Last nicht abfällt, und wenn ja, um welchen Wert.

Hello, Rainer

Hi Georg,

You are absolutely right, I should have written:
To simulate a lower temperature, you need to connect a resistor in series with the NTC. The effect is significantly greater at higher real temperatures than at lower real temperatures.

That's what happens when you don't finish the comfortable Ctrl+C and Ctrl+V, sorry.

Some approximate target values:
20°C = 2,7 kOhm
40°C = 1.2 kOhm
60°C = 600 Ohm
80°C = 330 Ohm.

These values apply to the 2-pole "only-temperature-trigger" type, for example, in the AFN and 1Z systems.
I don't have any target values for the combination sensor for boost pressure.
However, if the measured value corresponds to a specific temperature, the remaining target curve should also be the same.