Why the Speedometer of the Fiat 500 Flashes

This video explains why the speedometer showing the mileage on the Fiat 500 starts to flash. The primary reason is a loss of communication between the ECU and the module known as "Blue&Me". The main ECU requires all communication modules to be aligned according to the CanBus communication network, but when one of these modules fails, vehicle data can no longer be verified, causing the mileage data on the dashboard to flash.

The main suspect in these cases is the "Blue&Me" module, which has low-quality components and is prone to water ingress due to its location in the vehicle, leading to malfunctions including Bluetooth issues, which is its primary function, detectable via diagnostic tools.

The Bluetooth-related errors for this module are U1773 and U1733. Before replacing or resetting the module, you can perform some checks, such as disconnecting the negative terminal for 10 minutes to allow the ECU to reset all previous parameters (keep the radio code handy).

Also, check the wiring to and from the unit, as well as the fuses F51 and F36. If these checks are fine, locate the Blue&Me module in the left rear door panel, disconnect it to check for corrosion or damage, and test each pin to ensure it carries current.

If you find incorrect readings with the multimeter, check the wiring; if everything is fine, the module itself needs to be repaired.