VW Golf IV 1.6 16V 2001: Lambda Probe Heater Issue, Resistance & ECU Pin 5 - Troubleshooting

Hello
I have a problem with the above. by car, namely moments after deleting the error related to the Lambda probe heater Unit 1, appears again. The heater resistance has been checked and is about 4.4 ohms, the cables from the ECU to the probe have also been checked.

During the VCDS diagnosis in channel 041 the resistance of the heater for unit 1 and 2 is visible and here is the problem, the VCDS as the resistance value of the heater of the first unit still displays 0, while the resistance value of the heater for the unit 2 is visible and is about 4 ohms.

I am also wondering about one thing, the heater is powered directly from the fuse and there is no problem with it, I have power on it, while the mass is given from the ECU and instead of "pure mass" on pin 5 (heater mass) there is a value of 2V and here I have a question whether should there be some voltage in this pin or not?

PIN 5 ECU plug

Ecu controls the heater by providing the mass

Well, the ECU closes the circuit, but is 2V on this pin normal?

Plug in a 5W bulb instead of the heater and it should shine

I checked as you advised and with the ignition on, the bulb shines normally, while after firing it dims / pulses

Well, that's ok, the only defect of the heater remains ..

Hello,
I will dig up the old topic a bit, but I have been struggling with the lambda for some time. Should a 5W bulb connected to the lambda heater pins be flashing all the time after starting the engine? For me it is pulsating, then it goes out for a few seconds and then it starts to pulsate again. Group 041 shows only the values in windows 2, 3 and 4 and there are the following values:
2: alternating Htg S1 ON and Htg S1 OFF
3: 14-15 Ohm
4: Htg S2 ON