Circuit description
The
coolant
level in the engine is monitored by a level
switch. Pin 23 on the engine control unit (EMS2) pro-
vides pin 1 on the level switch with supply voltage. Pin
2 on the level switch is connected to battery negative
via pin 10 on the engine control unit. The level switch
has two states: On/Off.
The level switch consists of two sections, the actual
switch and a magnetic float which is built into the
expansion tank. The switch senses the position of the
magnetic float. When the coolant level falls, the float
operates the switch and a closed circuit is formed.
Measurements
Checking supply cable, coolant level
switch page 158
Checking negative cable, coolant level
switch page 158
Checking coolant level switch page 158
10
23
SB
LBN
EMS2
2
1
A
B
P0013497
a Connector B
b Coolant level
30-2 Fault Tracing
90 47701632 10-2013 © AB VOLVO PENTA