I changed out my Transmission and tranfercase on my DII and now my mileage on my Truck odometer is blinking on and off . Anyone got any ideas why?

 

Have to get your BCU re-programmed by computer. Usually happens when people swap dash cluster.

From page 1317 of 1529 in the shop manual:

Odometer update
The BCU can be programmed for one of two options:
l Option 1 – no odometer error warning.
l Option 2 – odometer error warning.
In order to provide an LCD flash request to the instrument pack via the communications link, the following inputs are
checked:
l Ignition state.
l Instrument pack odometer value (via the communications link).
l BCU odometer value.
The function is only active when the ignition state is on. The maximum allowed value is 999,999 miles (1,608,999
km).If the instrument pack odometer value is greater than the maximum allowed value, the maximum value is
assumed. The BCU odometer value is stored in EEPROM. If 16 identical values of the instrument pack odometer
reading is received consecutively, the instrument pack odometer value is compared with the BCU odometer value. If
the consecutive readings from the instrument pack differ, the BCU odometer value is incremented accordingly. If the
BCU odometer value is less than the instrument pack odometer value by up to 10 km, the BCU odometer value is set
equal to the instrument pack odometer value.
If the odometer warning option is enabled, and the contents of the instrument pack odometer value buffer is identical
to, or greater than BCU odometer value ± 10 km, the BCU sends an LED flash request to the instrument pack.
In the event of a communications link failure, this function will be unable to operate.