Owner's Manual for the vehicle. With a quick reference ... - E38.org

74nTemperature gauge
Service Interval Display
380de007
Between the blue and red zones
Normal operating range. It is not unusual
for the needle to rise as far as the
edge of the red zone in response to
high outside temperatures or severe
operating conditions.
Checking coolant level: Refer to
page 146.
380us008
Blue
The engine is still cold. Drive at moderate
engine and vehicle speeds.
Red
When you switch on the ignition, the
warning lamp comes on briefly to confirm
that the system is operational.
Lights up while driving, or the message
"COOLANT TEMPERATURE” appears
in the Check Control: the engine is
overheated. Switch the engine off immediately
and allow it to cool down.
Green lamps
The number of illuminated lamps decreases
as the time for your next maintenance
visit approaches.
Yellow lamp
This field appears together with
OILSERVICE or INSPECTION.
Maintenance is due. Please contact
your BMW center for an appointment.
Red lamp
Maintenance is overdue.