Function of the electrical coolant level indicator - ra20006010445x(0445)

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Engines 601, 602 (except 602.98), 603

Fig 1: Function Of Electrical Coolant Level Indicator

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

General

The coolant level indicator monitors the coolant level in the expansion tank when the engine is running.

The coolant level indicator lights up when the ignition is switched on (control function) and goes out as soon as the engine is running.

For the control function, the coolant level indicator shows a weak light and a bright light if there is a fault.

Components

Coolant level sensor (550) in expansion tank
Indicator lamp in instrument cluster.
Symbol: radiator.

To ensure that the coolant level sensor is not incorrectly installed, it has two lugs of different width which fit into the matching slots on the expansion tank (arrows).

It is press-fitted in the expansion tank and sealed with an O-ring. Remove locking ring in order to withdraw the coolant level sensor.

Fig 2: Locating Matching Slots On Expansion Tank

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Function

The coolant level in the expansion tank is sensed by a float (551) with permanent magnet attached to the coolant level sensor.

From a certain coolant level the contact is closed and the indicator lamp lights up.

Depending on driving style the indicator lamp lights up briefly at first and later shows a steady light. If the indicator lamp lights up, top up coolant.