Engine JAC HFC4DA1-2C. Service manual — part 39

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines

155

13.

DTC

P0380

The glow plug works without the command from ECU.

P0382

The glow plug doesn’t work with the command from ECU.

P0383

ECU control line for glow plug is short to ground.

P0384

ECU control line for glow plug is short to high level.

P0670

ECU control line for glow plug is open or its driver module is overheating.

Fault Description: The main part of glow plug is tubular heating element, which is securely and tightly installed
inside the glow plug shell, making it resistant to corrosion and thermal shock. The heating element is composed of
two resistance elements connected in series; they are installed in the top of heat pipe forming respectively a heating
coil and a control coil. The glow plug controller controls over the glow plug via a power relay and electrical switch
group. It can control the heating time of glow plug and also serve as a protection and monitoring device. The higher
level glow plug controller has diagnosis function, so it can distinguish an individual fault of glow plug and indicate it
to the driver. A multilevel socket is equipped on the control input terminal of glow plug controller for connecting with
ECU. To avoid voltage drop, screw pins or plugs should be equipped in the series circuit that is connected with the
glow plug. The post-heating upon a success start can facilitate the uninterrupted speed increase and idling with little
smoke in the process of heating, which can reduce the combustion noise in cold starting. If it fails, the glow plug
protection circuit shall open to avoid overdischarging of battery. If no preheating control signal is detected by ECU or
the detected control signal is inconsistent with the actual, relevant DTCs shall be generated.

Diagnosis Hint: The failure may be caused by poor contact of wire or loose connector. As for poor contact of ECU or
preheating control unit, check the harness connector for the following conditions:

Loose terminal

Poor matching and connection

Distortion or damage of terminal

Poor contact between terminal and wire

Damage of harness – Check the harness for any damage

Terminal ECU

K90

Control signal of preheating relay

K57 Preheating

time feedback signal

Glow plug

Power supply

Preheating control signal

Preheating feedback signal

Main relay

Preheating relay

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines

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Fault Tree:

检查预热塞接插件

做必要的修理

接插件问题

做必要的修理

检查ECU接插件

接插件问题

检查连续性和绝缘性

Y

N

Y

N

电气问题

Y

修理线束

更换预热塞

N

问题仍否存在

Y

联系技术支持

Check the connector of glow plug.

Connector fault

Repair accordingly.

Repair accordingly.

Check the ECU connector.

Connector fault

Check continuity and insulating property.

Electrical fault

Repair the harness.

Replace the glow plug.

Does the problem still exist?

Get the Technical Support.

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines

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14.

DTC

P0500

Error of vehicle speed sensor acquisition hardware

P0501

The vehicle speed sensor signal is unreliable.

Fault Description: Vehicle speed sensor (VSS) provides vehicle speed signals to ECU. It is a kind of Hall Effect
sensor. When the rotor gear tooth of transmission output shaft passes through the magnetic field of sensor, the VSS
shall generate a signal voltage, whose frequency shall increase with the vehicle speed. The ECU shall convert the
signal voltage into vehicle speed and make use of the vehicle speed signal to determine the working status of vehicle.
If this signal is lost or abnormal, relevant DTCs shall be generated.

Diagnosis Hint: Check the harness for any damage. If the harness appears normal, observe the indication on the
digital multimeter while moving relevant connector and harness of the actuator. If the indication changes in testing,
there must be failure in that part. The intermittent failure may be caused by poor contact, abrasion of wire insulation
or breakage of the wire inside insulation. Make sure the vehicle speed sensor is correctly fixed onto the transmission
housing.

Terminal ECU

K75

VVS input signal

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines

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Fault Tree:

Check the sensor connection.

Connector fault

Repair accordingly.

Check the ECU connector.

Connector fault

Repair accordingly.

Repair the harness.

Electrical fault

Check continuity and insulating property.

Check the VVS.

VVS fault

Replace the VVS.

Get the Technical Support.