I promised more details but there really aren't many. The paper work is very droll.
" CUSTOMER STATES CHECK ENG LIGHT ON
4C52 CHARGE AIR TEMP SENSOR PLAUSIBILITY STORED IN DME.
FAILURE OF CHARGE AIR TEMP. SENSOR.
INTERROGATED FAULT MEMORY. TESTED CHARGE AIR TEMP. SENSOR.
REPLACED CHARGE AIR TEMP SENSOR, CLEARD FAULT.
1 13-62-7-812-741 TEMPERATURE SENSOR WARRANTY $0"

The term "CHARGE AIR TEMP. SENSOR" is curious wording. I'm guessing it is short hand for "Turbo Charger Inter-cooler Air Temp Sensor" but I could be very wrong.

The failed part 13-62-7-812-741 costs roughly $25 retail. Because our dealer happened to have this part 'on hand', this repair only took roughly 2 hours So IMO EVERY dealer in the US should have at least one of these parts in stock.

Funf Dreisig

Edit: I forgot to add that our SA said we could not have the old part if it was covered under warranty, unless we were willing to pay for it He implied (but did not explictly say) that the dealers return the warranty parts for reimbursement. Does that sound right ?