3500B Marine Engines Caterpillar

The Electronic Control Module (ECM) monitors engine parameters. If a parameter extends outside an acceptable range, the ECM will initiate action. The ECM can cause a warning to occur. The ECM can derate engine power. The ECM can cause an engine shutdown to occur. Not all of the actions are available for all parameters.

The Caterpillar Electronic Technician (ET) can be used to select the ECM response. The Cat ET can be used to program the level of engine monitoring and the delay times.

Note: The following tables are examples. The values may have changed. Use the Cat ET to determine the actual defaults and the specific configuration.

Table 1

Programmable Monitoring System
Parameter	ECM Response	Default Trip Point	Default Delay Time	Limits
				Range for Trip Point		Delay Time
				Low	High
Low System Voltage	Off
	Warning	20 VDC	10 Seconds	20 VDC	22 VDC	1 to 30 seconds
Low Oil Pressure	Off
	Warning	(1)	4 Seconds	N/A		1 to 15 seconds
	Shutdown	(1)	9 Seconds	N/A		1 to 15 seconds
High Coolant Temperature	Off
	Warning	102 °C (216 °F)	5 Seconds	90 °C (194 °F)	102 °C (216 °F)	1 to 60 Seconds
	Derate	107 °C (225 °F)	30 Seconds	90 °C (194 °F)	107 °C (225 °F)	1 to 60 Seconds
	Shutdown	107 °C (225 °F)	5 Seconds	90 °C (194 °F)	107 °C (225 °F)	1 to 60 Seconds
Low Coolant Temperature	Off
	Warning	80 °C (176 °F)	5 Seconds	63 °C (145 °F)	85 °C (185 °F)	1 to 60 Seconds
Engine Overspeed	Off
	Warning	1.18 × Rated Speed	0 Seconds	1200 rpm	2400 rpm	0 to 5 Seconds
	Shutdown (50 Hz)	1.18 × Rated Speed	0 Seconds	1200 rpm	2400 rpm	0 to 5 Seconds
	Shutdown (60 Hz)	1.18 × Rated Speed	0 Seconds	1200 rpm	2400 rpm	0 to 5 Seconds
Air Filter Restriction Pressure	Off
	Warning	7 kPa (1 psi)	5 Seconds	3 kPa (0.4 psi)	7 kPa (1 psi)	1 to 60 Seconds
	Derate	7 kPa (1 psi)	5 Seconds	1 kPa (0.14 psi)	7 kPa (1 psi)	1 to 60 Seconds
Altitude	Off
	Derate	(2)	N/A	250 m (820 ft)	3658 m (12001 ft)	N/A
High Exhaust Temperature	Off
	Warning	(2)	5 Seconds	500 °C (932 °F)	800 °C (1472 °F)	1 to 60 Seconds
	Derate	(2)	5 Seconds			1 to 60 Seconds
Oil Filter Differential	Off
	Warning	105 kPa (15 psi)	5 Seconds	70 kPa (10 psi)	105 kPa (15 psi)	1 to 60 Seconds
Fuel Filter Differential	Off
	Warning	105 kPa (15 psi)	5 Seconds	70 kPa (10 psi)	105 kPa (15 psi)	1 to 60 Seconds
Crankcase Pressure	Off
	Warning	2 kPa (0.3 psi)	3 Seconds	0.5 kPa (0.1 psi)	6 kPa (0.9 psi)	1 to 30 Seconds
	Derate	6 kPa (0.9 psi)	10 Seconds	0.5 kPa (0.1 psi)	6 kPa (0.9 psi)	1 to 60 Seconds
	Shutdown	3.5 kPa (0.5 psi)	3 Seconds	0.5 kPa (0.1 psi)	6 kPa (0.9 psi)	1 to 60 Seconds
Aftercooler Water Temperature	Off
	Warning	102 °C (216 °F)	5 Seconds	40 °C (104 °F)	102 °C (216 °F)	1 to 60 Seconds
	Derate	107 °C (225 °F)	5 Seconds	40 °C (104 °F)	107°C (225 °F)	1 to 60 Seconds
	Shutdown	107 °C (225 °F)	5 Seconds	40 °C (104 °F)	107 °C (225 °F)	1 to 60 Seconds
Marine Gear Oil Temperature	Off
	Warning	99 °C (210 °F)	5 Seconds	20 °C (68 °F)	120 °C (248 °F)	1 to 120 seconds
Marine Gear Oil Pressure	Off
	Warning	1500 kPa (218 psi)	5 Seconds	900 kPa (131 psi)	2900 kPa (421 psi)	1 to 120 seconds

(1)	Refer to the oil pressure map.
(2)	Refer to the Performance and ratings manual.

Oil Pressure Map

Illustration 1	g00600573
Oil Pressure Map

Separate timers are used in the ECM for each response that is associated with a parameter. Once the trip point is exceeded for an action, the timer for that action is started. For example, if the high Coolant Temperature Warning is set to 102 °C (216 °F) with a five seconds delay, the delay timer starts counting once the coolant temperature exceeds 102 °C (216 °F). If the coolant remained above 102 °C (216 °F) for five seconds, a warning would be issued.

The engine monitoring system is enabled after the engine is started. When the engine is within 50 rpm of low idle, the ECM will check the parameters. The ECM will not check the parameter for low oil pressure. Low oil pressure has an additional 10 second delay after the engine is started. The delay is designed to eliminate false low oil pressure warnings.

Use care when you program the trip point and the delay times. The resulting ECM response must be correct for the application. If the legal range is not exceeded, the engine monitoring system will accept any setting.

If the trip point for a shutdown is lower than the trip point for a warning, the engine will shut down. The warning will not be activated.

Once a parameter has exceeded the trip point the parameter must drop a certain amount below the trip point before the ECM response will end.

If a warning is programmed to 102 °C (216 °F), the temperature must exceed the range in order for the warning to activate. The temperature must decrease below 99 °C (210 °F) for the warning to stop. The variance is the hysteresis. The following table gives the hysteresis for each parameter.

Table 2

Parameter	Hysteresis
ECM Voltage	3 VDC
Oil Pressure	50 kPa (7 psi)
High Coolant Temperature	3 °C or 6 °F
Low Coolant Temperature	3 °C or 6 °F
Overspeed	100 rpm
Air Inlet Restriction	N/A
Altitude	N/A
High Exhaust Temperature	102 °C (216 °F)
Oil Filter Differential Pressure	10 kPa (1.5 psi)
Fuel Filter Differential Pressure	10 kPa (1.5 psi)
Crankcase Pressure	N/A
Aftercooler Water Temperature	3 °C or 6 °F

Most active engine derates that occur are activated when the associated parameter is out of the specified range.

When the parameter returns to normal operation, the active engine derate is disengaged.

There are a few exceptions:

• High exhaust temperature

• High air filter restriction

• Crankcase pressure

The active engine derate is latched until the ECM is powered down.