Engine JAC HFC4DA1-2C. Manual — part 49

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

195

Fault Tree:

Get the Technical Support.

Repair the harness.

Repair accordingly.

Replace water level sensor.

Repair accordingly.

Repair accordingly.

Eliminate the fault.

Drain filter.

Is there still water?

Check water level sensor for electrical faults.

Are there still electrical faults?

Check water level sensor connectors.

Are there still connector faults?

Check water level sensor resistance.

Is there still resistance fault?

Check ECU connectors.

Are there still connector faults?

Check for continuity and insulating property.

Electrical fault

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

196

33.

DTC

P2299

Depress accelerator pedal and brake pedal at the same time.

Fault Description: Accelerator pedal assembly consists of two accelerator pedal position (APP) sensors. Accelerator
pedal position sensors are installed on pedal assembly and they are not maintainable. When driver depresses
accelerator pedal, air inflow of cylinder is increased and ECU increases fuel injector pulse width in order to supply
additional fuel during acceleration process for engine demand. Brake switch is a normally open one. When brake
pedal is depressed, this switch is closed in order to provide TCU with voltage for brake application. In the case of
misoperation of driver during driving, brake system will be locked after depressing brake pedal and brake pedal can
not return to its original position. Under such condition, depressing accelerator pedal will lead to DTC occurrence due
to conflict between acceleration and brake signals in the case of engine braking status. In addition, improper
maintenance or ECU control circuit failures will lead to such faults.

Diagnosis Hint: Check brake system and acceleration system for stuck pedal position without pedal returns. Check
the circuit between ECU and components for good contact of connection and good harness insulating property. For
connection test for ECU and components, diagnostic connectors should be applied.

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

197

Fault Tree:

Get the Technical Support.

Replace the harness.

Replace it accordingly.

Replace it accordingly.

Check brake system and acceleration system

mechanical parts.

Mechanical part failures

Check accelerator switch adjusting position.

Check switch position for improper

adjustment.

Adjust accelerator switch position

(accelerator pedal electric

potential standard value: 750±

85mv)

Check ECU for connector faults.

Check connecting circuit

between ECU and the system.

Connecting circuit failures

Replace the ECU and carry out debugging.

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

198

34.

DTC U0167

In the case of the maximum fault reading, there are EEPROM errors/ICM
time-out communication failures.

Fault Description: They are mainly taken as integrity failures for ECU internal microprocessor, being applied in
determination of ECU programming procedure implementation. In the case of engine shutdown and ignition switch
connection, ECU carries out self-diagnosis. In the case of diagnosis failure, control module records operation
condition under diagnosis failure and stores this information in “Fault Record”, DTC occurs. During engine operation,
when there is deviation between ECU detected signals and standard signals, the fault will be stored and expressed as
DTC via internal communication module of ECU. In the case of external signal intrusion, this will lead to system
disorder and DTC occurs. When various faults occur at the same time under the same operation condition, there will
be multiple DTCs. For there is a process for ECU response to each fault, ECU response time will be longer in the case
of multiple simultaneous faults in existence. During response process, DTC may occur due to ECU internal
communication errors or hardware faults.

Diagnosis Hint: In the case of fault occurrence, relevant test can be carried out after ECU replacement for possible
fault cause may be too long ECU internal response time. Check ECU circuit to verify whether it is circuit failure that
leads to fault occurrence.