user31102: I'm trying to find the I2C address of an IMU plugged into my Arduino using the code from this URL: http://playground.arduino.cc/Main/I2cScanner.  However, the program stalls at this stage:

Why could this be happening?

user30198: When the I2C scanner stops, it halts in the function Wire.endTransmission. The cause is a hardware problem of the I2C bus. For example the SDA or SCL are shortcut to something or pull-up resistors are missing (as already mentioned by TisteAndii) or the sensor module is not powered. 
I assume that the IMU module has already pull-up resistors for SDA and SCL on the module. Which IMU module is it ? How did you connect it ? Do you have other I2C modules to test the I2C bus ?

31102: <p>I'm trying to find the I2C address of an IMU plugged into my Arduino using the code from this URL: <a href="http://playground.arduino.cc/Main/I2cScanner" rel="nofollow noreferrer">http://playground.arduino.cc/Main/I2cScanner</a>.  However, the program stalls at this stage:</p>

<p><a href="https://i.stack.imgur.com/MsDnS.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/MsDnS.jpg" alt="enter image description here"></a></p>

<p>Why could this be happening?</p>
 30198: <p>When the I2C scanner stops, it halts in the function Wire.endTransmission. The cause is a hardware problem of the I2C bus. For example the SDA or SCL are shortcut to something or pull-up resistors are missing (as already mentioned by TisteAndii) or the sensor module is not powered. </p>

<p>I assume that the IMU module has already pull-up resistors for SDA and SCL on the module. Which IMU module is it ? How did you connect it ? Do you have other I2C modules to test the I2C bus ?</p>
