Checking
If the TID or the radio is removed for diagnosis purposes, inspect all plug connections carefully; if necessary, open plug casing and bend contact springs straight.
Equally, check the ambient temperature sensor plug connection and clean if necessary.
If there is no automatic antenna signal (AA), there will be no radio display; only the date will be shown. Check the automatic antenna signal using Multimeter MKM-587-A. If the voltage is less than 9 V with the radio switched on, start trouble-shooting as follows:
1. Eliminate the possibility of contact problems.
2. Eliminate the possibility of a short circuit to ground in the line between the radio/TID and the electronics of the roof antenna.
3. Disconnect plug from the roof antenna and measure the automatic antenna signal with the radio switched on. If the above mentioned nominal value is not attained, the radio or the TID is defective. If the nominal value is attained, the roof antenna is the cause of the fault.