LDA Indicator After Rainer's Tuning - Tested on 96kW TDI

Hello,

Today, I tapped into the wiring of the LD/LT sensor on my 96kW TDI.
Since I couldn't easily access the sensor's connector, I simply pierced the wires to determine which wire corresponds to which function. Here are the measurement results:

Gray/blue cable = ground.
Green/blue cable = voltage?
Cable color: yellow/black = LD Output.
Purple cable = LT Output.

'When I measure the voltage between the purple wire and ground, I get approximately 2.7V at idle. When driving in city traffic, I get around 3.3-3.5V. The voltage increases further at higher speeds.'

1. Question: Does the temperature sensor provide a linear signal?
2. Question: Which regulatory area is involved? What is the voltage at approximately 90°C LT?

When I measure the supply voltage, I get approximately 2.3V, and I was surprised that it increases and decreases during the test drive. I have installed a P-box, but the manufacturer states that it does not manipulate the boost pressure, but only increases the fuel injection amounts -> Could it still be due to the chip that this voltage changes?

When I measure the voltage between the yellow wire and ground, I get approximately 0.0-0.4V at idle. The peak voltage I observed was a maximum of 2.66V, and under full load (3rd gear + handbrake at approximately 3500/min), I measured 2.44V.

When I compare my values with Rainer's values, it becomes apparent that I most likely have a different combination sensor installed.
>> Does anyone have a datasheet for the sensor used?
Unfortunately, I've lent out my diagnostic tool at the moment, so I can't compare my values using VAG-Com.

Best regards,

Toby.

Hi,

The supply voltage for the boost pressure sensor is 5V. Unfortunately, I don't have access to the characteristic curve of the temperature sensor.

Best regards, Rainer.

Hello again,

'The circuit is actually working in my TDI now. However, I'm using a slightly modified sensor. At idle, I'm getting approximately 2.6V instead of 2.86V. Therefore, I've divided my voltage using resistors with values of 16kΩ and 10kΩ.'

If I have a working temperature circuit tomorrow, I will post again here. I and my colleagues have already collected measurements today.

The mistake I made during my first measurement over the weekend was that I measured the voltage between the 5V line and the signal lines...

Hi and thanks again for the brilliant idea.

toby

P.S.: I measured the absolute boost pressure in the 9th measurement block under 'intake pressure.' Was that correct, or is there a separate measurement block for the actual overpressure?

Hi Toby,

Thank you for the feedback. Could it be that you mean 1.6V or 1.82V instead of 2.xV?

Best regards, Rainer.

Yes, of course, that was a little bit of a trickster .

See you soon.

toby