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© 2 0 0 6 D i r e c t e d E l e c t r o n i c s
Step 4, H2 Harness
Engine Monitoring Explained
During remote start the system will need to know if the engine is
running. The module does this by monitoring the voltage of the
vehicle's electrical system (or the tachometer-see next section).
Voltage Monitoring
Vehicle electrical systems usually rest at about 12.6 volts when
the engine is not running. This system is programmed to detect
the rise in battery voltage that occurs when the charging circuit
activates after starting, and keep the engine running if the rise is
adequate. It will make up to three start attempts before discon-
tinuing due to an inadequate voltage rise.
Some vehicles have alternators that do not activate immediately
or do not increase voltage sufficiently after starting, this system
will compensate by delaying the time before reading the battery
voltage on the second and third start attempts. This delay will
allow most alternators to activate so the remote start will
continue to run.
The voltage read times are:
First attempt: 10 seconds
Second attempt: 20 seconds
Third attempt: 50 seconds
After the third start attempt, if the voltage increase is still not
adequate to keep the engine running, the Tachometer input
option should be used to monitor the engine.
note!
If the system has been programmed for
Tachometer monitoring previously, it must be
reprogrammed to Voltage monitoring.
