V8 EngineAJ-V6/AJ28
57
Air Assisted Injection
The air assisted injection system is very similar to
the AJ27 system, with a solenoid valve controlling
an air supply to the fuel injector nozzles. The AJ28
engine uses a different type of injector and air
assist control AAC valve. The AAC valve bolts to
the side of the throttle adaptor which provides an
inlet port connection from the intake resonator
duct via a hose and an outlet port to the air rails.
The injectors are located in the air rails which are
integral with the manifold.
J.303.1257
AAC VALVE AND AIR DISTRIBUTION
J.303.1257
J.303.1392
AAC VALVE
J.303-1392
Valve shown in the closed,
de-energised state
InletOutlet
AAC Valve
Powertrain ManagementAJ-V6/AJ28
69
Introduction
All powertrain and associated management
functions are controlled from a single unit, the
powertrain control module (PCM). These
functions are as follows:
¥ overall monitoring and control of
performance, fuel economy, emissions,
driveability and safety
¥ receives and processes direct inputs from
engine, transmission, fuel system and
ancillary systems sensors
¥ provides direct control of actuator devices
¥ communicates with other modules via the
SCP bus (eg to obtain wheel speed
information)
¥ provides system diagnostics to conform to
OBDII requirements.
Powertrain Control Module (PCM)
The basic PCM is common to the V6 and V8
engines but with unique programming to suit the
respective engine characteristics and some
differences in the interface circuits for the
different sensors and actuators.
The PCM is located below the LH or RH mounted
A/C evaporator/blower unit and has a single
connector panel which protrudes through the
forward bulkhead into the engine bay.
The PCM has three connectors:
¥ a 60 pin connector which provides the
interfacing with the engine wiring harness:
carries engine mounted sensor inputs and
output control signals
¥ a 32 pin connector which carries the
transmission sensing and control signals and
also the rear HO2 sensor inputs
¥ a 58 pin connector which carries non engine
mounted sensor and actuator signals and
provides the PCM link to the SCP bus.
Powertrain Sub-Systems
Brief descriptions of PCM control of new
subsystems are given in the relevant engine and
transmission sections (electronic throttle,
returnless fuel etc).
J.303.1393
POWERTRAIN CONTROL MODULE
J.303.1393
