MARELLI 48P2 INJECTION SYSTEM

2.0 16V

INTRODUCTION

The MARELLI 48P fitted to the 1998 16v engine belongs to the category of integrated systems with digital electronic control via an ignition microprocessor with static advance and distribution and indirect intermittent multipoint injection.The system is able to record a set of parameters via specific sensors or voltage data:engine rpm;the correct cylinder combustion TDC sequence (injection timing);absolute pressure in the intake manifold;intake air temperature;coolant temperature;throttle position and closure/opening speed;presence of oxygen in the exhaust gases;vehicle speed;exhaust gas recirculation solenoid position;knock (if present);air conditioner activation (where applicable);power steering end travel;battery voltage.The analogue signals are converted into digital signals by analogue/digital (A/D) converters so that they can be used by the control unit.The control unit memory contains a management program (software) that includes a set of strategies, each of which manages a specific system control function.Each strategy uses the information (input) described above to process a set of parameters based on data maps stored in specific areas of the control unit. The strategy then controls the system actuators (output), i.e.the devices that allow the vehicle to operate, namely:control relays;injectors;ignition coils;actuation solenoids;interface with other control units on the vehicle (automatic transmission, ABS, speed regulator etc.);interface with the in-car service control unit (in-car computer, climate control system, coded immobiliser).The integrated system may be broken down schematically into the following subsystems:ELECTRIC/ELECTRONIC CIRCUIT;AIR INTAKE CIRCUIT;FUEL FEED CIRCUIT;EMISSION CONTROL DEVICES.

The MARELLI 48P2 injection-ignition system does not require any adjustment because it is self-adaptive