Mercedes-Benz GLB 2023 Operator's Manual page 421

Warning/indicator lamp Possible causes/consequences and
; * The yellow Check Engine warning lamp is lit while the engine is running.
A malfunction has occurred in the engine, the exhaust system or the fuel system.
The emissions limit value may have been exceeded and the engine may be running in emergency operation mode.
Check Engine warning lamp
In some states, legal requirements stipulate that you must immediately consult a qualified specialist workshop as soon
as the yellow Check Engine warning lamp lights up.
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# * The red electrical malfunction warning lamp is lit.
There is a malfunction in the electrics.
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Electrical malfunction warn-
ing lamp
æ * The yellow fuel reserve warning lamp lights up while you are driving.
There has been pressure loss in the fuel system. The fuel filler cap is not closed correctly or the fuel system is leaking.
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Fuel reserve warning lamp
If the fuel filler cap has already been closed correctly:
flashes
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Solutions
M
Have the vehicle checked as soon as possible at a qualified specialist workshop.
Note the messages on the instrument display.
Close the fuel filler cap.
Consult a qualified specialist workshop.
Display messages and warning/indicator lamps 419