Maybe some help to you, but just looking up this code on the net:
U1701 Troubleshooting
When the check engine light comes Fiat Grande+Punto U1701 code on the first you should check is the gas cap. Pull over, retighten it, and take a look at the cap to see if it has any cracks in it. Continue driving and see if the check engine light turns off.
The most common causes of this U1701 code being stored are due to a defective input speed sensor or output speed sensor. Other common causes include shorted, open, corroded, or damaged wiring circuits or connector
The crankshaft sensor signals the fuel injection computer or the ignition control when the cylinders are firing. This causes the ignition coil to provide a spark and the injector to inject fuel into each cylinder at the right time.If either sensor isn't working correctly, the car will run rough and the engine will be less efficient. In later car models, the car's computer can usually keep the vehicle running, but the engine warning light on the dashboard goes on to warn the driver.
A sure sign of this is smoke or steam being emitted from underneath the hood. The ignition timing could be set incorrectly and will require adjustment. If, when looking under the hood, you notice that the drive belts appear loose, they need to be tightened or completely replaced. If there is a noticeable pool of fluid underneath the car, this could be a sign of the cylinder head gasket failing. That will be confirmed in the form of billowing smoke being blown from the exhaust system. U1701 OBD2 may also be triggered by faults earlier down the line. For example, a dirty MAF sensor might be causing the car to overcompensate in its fuel-trim adjustments. As a result, oxygen sensors are likely to report fuel mixture problems.
Not sure if it helps but may point you in the right direction.....
