Engine management system - Td5 (Description): Description and operation

Description

General

An engine control module (ECM) controls the five-cylinder direct injection diesel engine, and works on the drive by wire principle. This means there is no throttle cable, the ECM controls the drivers needs via a signal from the Throttle Position (TP) sensor on the throttle pedal.

The ECM is a full authoritative diesel specific microprocessor that also incorporates features for cruise control and air conditioning control. In addition, the ECM supplies output control for the exhaust gas recirculation and turbocharger boost pressure. The ECM has a self-diagnostic function, which is able to provide backup strategies for most sensor failures.

The ECM processes information from the following input sources: l Mass air flow sensor. l Ambient air pressure sensor. l Manifold absolute pressure/inlet air temperature sensor. l Engine coolant temperature sensor. l Crankshaft speed and position sensor. l Throttle position sensor. l Fuel temperature sensor. l Air conditioning request. l Air conditioning fan request. l Brake pedal switch. l Clutch switch. l Cruise control master switch. l Cruise control SET+ switch. l Cruise control RES switch. l High/low ratio switch.

The input from the sensors constantly updates the ECM with the current operating condition of the engine. Once the ECM has compared current information with stored information within its memory, it can make any adjustment it requires to the operation of the engine via the following: l Air conditioning clutch relay. l Air conditioning cooling fan relay. l Electronic vacuum regulator solenoid. l Malfunction indicator lamp. l Fuel pump relay. l Glow plug warning lamp. l Glow plugs. l Fuel injectors. l Main relay. l Turbocharger wastegate modulator. l Temperature gauge.

The ECM interfaces with the following: l Electronic Automatic Transmission (EAT). l Self Levelling and Anti-lock Brakes System (SLABS). l Serial communication link. l Instrument cluster. l Body Control Unit (BCU).