Installation Manual

Electrical & Electronic Application And Installation Manual
Production Release Version 1.0
Page 171
12.6 Engine Soft Start Protection
12.6.1 Engine Soft Start Protection Operation
After starting, a soft start strategy is employed which holds the engine speed
at low idle or 850rpm depending on which is lowest for a duration between 1
and 25 seconds to allow engine systems to stabilise.
Under normal system conditions, the trigger to exit the soft start strategy is oil
pressure. The time taken to build oil pressure depends on many factors, for
example
• Ambient temperature
• Oil temperature
• Oil grade
• Oil filter position
• Time since engine last run
• Engine starting performance
Following the exit of the soft start strategy, the engine will ramp to the desired
engine speed.
The soft start strategy includes a maximum allowed hold time, as backup in
the event of a system failure, for example, oil pressure sensor failure. Soft
start mode will be exited at the expiry of this maximum hold time, irrespective
of whether oil pressure has been detected. In this case, normal engine
diagnostics will apply. The maximum hold time is dependent on temperature,
and is in the range 5 to 25 seconds.
12.6.2 Engine Soft Start Protection Configuration
There is no specific user configuration required for this feature.
12.6.3 Engine Soft Start Protection Installation
The engine ECM provides two methods for communicating the status of the
soft start feature to the machine operator.
Option 1 Engine Wait to Start Lamp flash
The engine ECM will flash the Wait to start lamp output driver at a frequency
of 2Hz for the duration of the soft start condition. Once conditions have been
met for the exit of the soft start feature to occur the wait to start driver will turn
off.
Option 2 J1939 Engine Oil Priming State (SPN 3551)
The engine ECM will communicate the status of the soft start feature via the
J1939 datalink PGN FE6A (65130) SPN Engine Oil Priming State 3551. More
details on the format of this message can be found in section 19.3.31 of this
document.
The Engine Oil Priming State will operate as follows;