Circuit description
In order to avoid boiling in the charge air coolers at
different loads and coolant temperatures, the system
is fitted with a cold start valve that is controlled by the
EMS2.
The
cold start valve is normally open i.e. without
voltage supply the valve is open. The cold start valve
is supplied with battery voltage at pin 4. Pin 1 is con-
nected to pin B34 at the EMS2. When the cold start
valve is activated(valve closes) pin B34 alter its voltage
potential from battery voltage to approx. 0.2 Volt.
If the intake manifold temperature signal or the coolant
temperature signal is lost the cold start valve opens.
Under normal conditions, the cold start valve is opened
at:
intake manifold temperature>50° AND coolant water
temperature<86°.
Under normal conditions, the cold start valve is closed
at:
intake manifold temperature<45° OR coolant water
temperature>92°.
Measurements
Checking supply cable, coldstart valve page 173
Checking negative cable, coldstart valve page 174
P0013519
EMS2
A
VO
B
R /BL
34
1
4
(+)57,60
P0013520
A Junction point
B Cold start valve
30-2 Fault Tracing
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