Coolant level sensor
Coolant level sensor |
The coolant level sensor is moulded into the bottom of the expansion tank. The sensor fits in the hollow pillar on the outside of the expansion tank.
The SID unit applies B+ to level sensor via pin 22 and the sensor is grounded at grounding point G33P respective G34S (LHD respective RHD). At normal level, the float contacts the switch and the solenoid in the float closes the circuit and the SID unit pin 22 is grounded. At low level, the circuit to ground is opened.
The function gives CHECK messages on the SID (30 second delay). For further information, see SID, Technical description, CHECK messages .
Diagnosis |
When the circuit is opened to the coolant sensor, the text message “FILL COOLANT FLUID” is displayed despite correct coolant level.
In case of shorting to ground, the CHECK message will not be displayed even if the level is low.
The SID unit will not generate a diagnostic trouble code.