JAC J2 User Manual

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Maintenance Manual for J2 Sedan
Electronic Control System
of Engine
167
related to the sensor and actuator can be read with the diagnosis apparatus, and the actuator may be
driven forcibly in
some cases.
12.
Other
Control
Functions
1)
Fuel
Injection
Pump
With relay connected, the fuel injection pump will be energized when the crankshaft starts to rotate or
with engine running.
2)
Fan
Relay
Control
The speeds of the radiator fan and condenser fan is controlled with the engine coolant temperature,
vehicle speed and air conditioner switch signal (AC).
III. On-board Diagnosis System
1. Description
On-board diagnosis system (hereinafter referred to as OBD
system) is
the diagnosis system integrated in
the engine control system to monitor the trouble components affecting the emission as well as the main
function state of the engine. It is capable of identifying, storing and showing the trouble information
through the
self-diagnosis malfunct
ion indicator lamp (MIL).
2. Trouble
Informat
ion Record
Electronic control module constantly monitors the sensor, actuator, associated circuit, malfunction
indicator lamp (MIL) and battery voltage etc. as well as even the electronic control module itself, and
carries out the credibility detection for the output signal of sensor, the drive signal of actuator and the
internal signal (such as λ closed-loop control, coolant temperature, idling speed control and battery
voltage control etc.). Once a trouble is found in some link or a signal value is incredible, the electronic
control module immediately sets the trouble information record in RAM memory. Trouble information
record is stored in form of
DTC and shown based on the o
rder in which the troubles present.
The troubles can be divided into “steady-state trouble" and "sporadic trouble" according to their
occurrence frequencies (for example, because of short term open circuit of harness or poor contact of
connector).

JAC J2 Specifications

General

Brand	JAC
Model	J2
Category	Automobile
Language	English