Jeep Cherokee (XJ): CCD bus (+/-) circuits-pcm outputs. Data link connector-pcm input and output. Fuel injectors-pcm output
OPERATION The Powertrain Control Module (PCM) sends certain
output signals through the CCD bus circuits.
These signals are used to control certain instrument
panel located items and to determine certain identification
numbers.
Refer to Group 8E, Instrument Panel and Gauges
for additional information. DESCRIPTION The data link connector is located at the lower
edge of the instrument panel near the steering column. OPERATION The 16-way data link connector (diagnostic scan
tool connector) links the Diagnostic Readout Box
(DRB) scan tool or the Mopar Diagnostic System
(MDS) with the Powertrain Control Module (PCM). DESCRIPTION The fuel injectors are connected to the engine with
the fuel injector rail. OPERATION The nozzle ends of the injectors are positioned into
openings in the intake manifold just above the intake
valve ports of the cylinder head. The engine wiring
harness connector for each fuel injector is equipped
with an attached numerical tag (INJ 1, INJ 2 etc.).
This is used to identify each fuel injector with its
respective cylinder number.
The injectors are energized individually in a
sequential order by the Powertrain Control Module
(PCM). The PCM will adjust injector pulse width by
switching the ground path to each individual injector
on and off. Injector pulse width is the period of time
that the injector is energized. The PCM will adjust
injector pulse width based on various inputs it
receives.
Battery voltage (12 volts +) is supplied to the injectors
through the ASD relay. The ASD relay will shutdown
the 12 volt power source to the fuel injectors if
the PCM senses the ignition is on, but the engine is
not running. This occurs after the engine has not
been running for approximately 1.8 seconds.
The PCM determines injector on-time (pulse width)
based on various inputs.CCD bus (+/-) circuits-pcm outputs
Data link connector-pcm input and
output
Fuel injectors-pcm output
Fuel pump relay-pcm output. Idle air control (iac) motor-pcm
output. Radiator fan relay-pcm output
Other materials:
Wiper motor. Wiper switch and washer switch. Washer system
Wiper motor
FRONT
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the wiper arms from the wiper pivots.
See Wiper Arm in this group for the procedures.
(3) Remove the eight screws that secure the cowl
plenum cover/grille panel and screen to the cowl top
panel (Fig. 9).
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