I2C communication with Honeywell Zephyr flow sensor not working

I have a HAFBLF0200C2AX5 Honeywell Zephyr flow sensor.
datasheet: http://sensing.honeywell.com/honeywell-sensing-zephyr-digital-airflow-sensors-product-sheet-008178-7-en.pdf

I can’t make it talk to my arduino.
I know its address should be 0x29. I ran a couple of i2c address scanners, which don’t give me any response at all.
I have the clock and data line pulled up with 4.7k resistors as was recommended, but still nothing. Can anybody help me out?

Use the i2c_scanner from the arduino Playground or the one from gammon.com.au I can't see it very well on my tablet. Are SDA and SCL connected to A4 and A5 ?

Thanks for answering Peter,

Yes. I double and tripple checked the wires. The i2c scanner was the first thing I used. It just stops at “scanning” and does not finish its loop. Tried with another i2c device which just worked fine. I have a hunch that it has something to do with the pull-up resistors but any help to how to make it work and read the

Probably halted at "Wire.endTransmission()". That happens when SDA or SCL is shortcut to ground or when they are shortcut to each other. Perhaps something is wrong near the sensor. Does the sensor have power ? Is the soldering okay ?

That sensor works also at 5V ? I did check it, but I forgot it... If it runs at 5V you could add pullup resistors. 4k7 from SDA to 5V and 4k7 from SCL to 5V.

it is indeed a 5 volts sensor. just put a second device on the lines, and now both devices are detected. When trying to detect the single zephyr sensor however, there is still no detection. So, power and everything should be ok.

Did you try a single sensor with the extra pullup resistors ?