Volvo VNL Operator's Manual page 255

250 Engine Start and Operation
Coolant
Temperature
Above +120 F (50 C)
Above +50 F (10 C)
Between +4 F (-15 C)
and +50 F (10 C)
Below +4 F (-15 C)
When the engine has started, the preheater
may be re-engaged to assist in faster engine
warm-up. To re-engage, turn the key to the
preheat position and the preheater will en-
gage. The starter will not engage as the
start position is locked out.
Engines Without Preheater
Engines not equipped may, depending on
coolant temperature, take longer to start. If
this should happen, do not release the igni-
tion key until the engine has started (while
still observing the 30 second maximum
cranking time).
Preheater
Engagement
Time (seconds)
0
0
25 ± 2 to 50 ± 2
50