Engine Timing And Electronic Controls; General Information - Perkins 2800 Workshop Manual

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Engine timing and electronic controls

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General information

The 2800 Series electronic control system consists of the Electronic Control Module (ECM) and engine
sensors. The ECM, mounted on the left side of the engine, is the computer which controls the engine operating
parameters. The software stores the operating maps which define power, engine speed, etc. Electronic unit
injectors are fitted to each cylinder. A solenoid on each injector controls the amount of fuel delivered by the
injector. The ECM sends a signal to each injector solenoid to provide complete control of the engine. The ECM
compares the 'desired speed' with the actual engine speed, obtained from sensors on the crankshaft and
camshaft drives, and calculates how much fuel to inject to achieve the desired speed.
The timing of the fuel injection is determined by the ECM after it has received information from the coolant
temperature sensor, the air temperature sensor of the inlet manifold and the turbocharger boost pressure
sensor. From a signal provided by the engine speed/timing sensor, the ECM determines where top dead centre
on cylinder number one is located. The ECM decides when injection should occur relative to top dead centre
and provides a signal to the injector at the desired time. The ECM adjusts timing for the best engine
performance, fuel economy and white smoke control. Actual or desired timing can be viewed with the service
tool.
The ECM controls the amount of fuel injected by varying signals to the injectors. The ECM sends a high voltage
signal to energise the solenoids of the fuel injectors. The injectors will pump fuel ONLY if the injector solenoid
is energised.
Warning! The electrical circuit for the fuel injector units operates on 110 volts. Do NOT work on the fuel injector
units unless the power supply to the ECM has been disconnected.
The software inside the ECM sets limits on the amount of fuel that can be injected dependent on the selected
rating and the engine operating parameters. The parameters which follow are monitored by the ECM: High
coolant temperature, low lubricating oil pressure, overspeed condition, inlet manifold air temperature, fuel
temperature and boost pressure.
The electronic system has some ability to diagnose itself. When a diagnostic code is generated, the
'Diagnostics' lamp is illuminated and the exact fault should be determined by use of the service tool. Full
information on fault finding the system is given in the Diagnostic Manual, TSD3453.
The ECM communicates with the service tool through the Perkins Data Link (PDL); a connector is normally
fitted to the wiring harness to enable the service tool to be connected. A J1939 data link is also available in
addition to the Perkins Data Link.
Workshop Manual, TSD3450E, Issue 1 87