Haima 7 User manual

General Precautions of EFI System Maintenance

F-1

I. Electronic fuel injection system general knowledge of maintenance

1.1 General Precaution for Maintenance

l Only digital multimeter and malfunction diagnosis intrument can be used to inspect the electronic fuel

injection system.

l To ensure normal operation of electronic controlled fuel injection, use the genuine parts for maintenance.

l Only unleaded gasoline should be used for maintenance.

l Please follow standard procedures of maintenance and diagnosis.Do not disassemble any part of the

electronic fuel injection system.

l Be very careful when holding the electronic components (electronic control unit, sensor etc.). Do not

drop them onto the ground.

l Be aware of the environmental protection. Properly dispose the waste generated in maintenance.

1.2 Precautions for Maintenance

1) Don’t disconnect any parts or connectors of the electronic fuel injection system, otherwise they may

be damaged or cause water, oil pollution and other impurities entering into connectors resulting in

impairing of performance.

2) Ignition switch should always be turned off when disconnecting/connecting connectors or the

electronic component will be damaged.

3) When performing trouble thermal simulation and other operation which may cause increase of

temperature, the temperature of electronic control unit must not be higher than 80°C.

4) As feed pressure of electronic fuel injection system is high (about 400kPa), all fuel pipes should be

of high resistance. Even with engine not running, the fuel pressure is relative high in the fuel pipe.

Therefore, do not disconnect the fuel pipe casually in maintenance. Perform the process of pressure

relief before disconnecting the fuel pipe if fuel system needs to be repaired. The process is as follows:

remove fuel pump relay and start engine and operate it at idling speed; connect diagnosis instrument;

enter into “actuator test” to stop fuel pump until engine stops automatically. Removal of fuel pipe

and the replacement of fuel filter should be conducted by professional technicians at place of good

ventilation.

5) To prevent electric spark which may cause fire accident, do not electrify the fuel pump when it is

removed from fuel tank.

6) Do not test the fuel pump in dry state or in water, otherwise service life may be impaired. Do not

connect the positive and negative electrode wrong.

7) During inspection of ignition system, perform the sparking test only when necessary and the testing

time should be as short as possible. Throttle can not be open, or unburned fuel will enter into the

exhaust pipe resulting in three-element catalyst converter damaged.

8) As idling speed is adjusted completely by electronic fuel injection system, no human adjustment is

needed. The accelerator limit screw of throttle body is adjusted before leaving factory. Users must

not change it under any conditions.

9) Connecting the positive and negative electrode wrong may cause electronic components damaged.

Negative ground is used in this system.

10) Battery cable must not be disconnected with engine running.

11) Before electric welding, disconnect positive and negative electrode of the battery and remove

electronic components.

12) Do not transpierce the skin of the wire to test the input and output electric signals of parts.

General Precautions of EFI System Maintenance

F-2

1.3 List of Maintenance Tools

Tool name:

Electronic fuel injection system Instrument

Function:

Read/clear P-CODE of electronic fuel injection

system and observe data flow, motion test of spare

parts and so on.

Tool name:

Ignition Timing Light

Function:

Check the ignition timing of the engine.

General Precautions of EFI System Maintenance

F-3

Tool name:

Digital Multimeter:

Function:

Check characteristic parameters of electronic fuel

injection system like voltage, current, resistance and

so on.

Tool name:

Vacuum Meter

Function:

Check the pressure of intake manifold and so on.

Tool name:

Cylinder Pressure Gauge

Function:

Check the cylinder pressure condition of each

cylinder.

General Precautions of EFI System Maintenance

F-4

Tool name:

Fuel Pressure Gauge

Function:

Check the pressure situation of fuel system and

judge the working condition of fuel pump and fuel

pressure regulator in the fuel system.

Tool name:

Exhaust Analyzer

Function:

Check the exhaust emissions of vehicles and it

helps to make a sound judgment on the

malfunctions of electronic fuel injection system.

Tool name:

Injector Cleaning Analyzer

Function:

Analyze the cleaning operations on fuel

injector.

General Precautions of EFI System Maintenance

F-5

II. Diagnosis Flow for Inspection and Maintenance by ME7 System

according to P-CODE

Descriptions:

1. Te following items of inspection and maintenance are performed only after the malfunction has been

confirmed to be a steady-state malfunction currently, and otherwise it will lead to diagnostic errors.

2. The “multimeter” mentioned on following occasions indicates the digital multimeter. It is prohibited to

examine the lines of electronic injection system using pointer multimeter.

3. In the case when vehicle with anti-theft system is inspected and repaired, if the occasion for replacement

of ECU appears in the column of “Follow-up Steps”, pay attention that the anti-theft system must be

matched after replacement.

4. In this system: When P-CODEs of P000A, P000B, P0012, P0015, P0170, P0171, P0172, P0219, P0560,

P0562, P0563, P0668, P0704, P1336, P1559, P1564, P1579, P1604, P1651 and P2138 exists, the SVS

and MIL lamps will not turn on in either of the cases.

5. If P-CODE indicates that the voltage of certain circuit is too low, it indicates that the short circuit to

ground may possibly exist in this circuit. If P-CODE indicates that the voltage of certain circuit is too

high, it indicates that short circuit to power supply may possibly exist in this circuit. If P-CODE indicates

that it is the malfunction of certain circuit, it indicates that open circuit may possibly exist or multiple

line malfunctions exist in this circuit.

6. In this system, the mark is the SVS lamp and the mark is the MIL lamp.

Diagnostic Help:

1. In the case when malfunction cannot be removed, the malfunction belongs to a steady-state

malfunction.

The priority is to be given to examine whether or not loosening effect exists with the joint of wire

harness if it is random malfunction.

2. Examination has been made according to the abovementioned steps, and no anomalies are found.

3. Don’t ignore vehicle maintenance status, cylinder pressure, mechanical ignition timing, and other

factors of impact on the system during inspection and maintenance.

4. Test shall be performed, if ECU is to be replaced.

If the P-CODE can be removed at this point, then the malfunction part is at ECU, and if P-CODE

still cannot be removed at this point, then the original ECU shall be changed back, to carry out the

work on inspection and maintenance once again, in the repeated flow.

General Precautions of EFI System Maintenance

F-6

1. P000A Abnormal Operation of Air Intake VVT

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function, Digital Multimeter, and

Correct Circuit Diagram)

Description about Malfunction Cause: The actual position deviates greatly from the target position of VVT.

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

P-CODE Present P-CODE Present

P000A

Maintenance tips:

The malfunction has been confirmed, and the

following problems may possibly exist:

1) VVT is jammed at certain position of large

opening;

2) VVT is jammed near the block position;

3) VVT runs very slowly, resulting in big

deviation between target and actual position.

Maintenance tips:

Unstable idling speed or rough running of engine may

appear, please check VVT or replace it when

necessary.

2. P000B Abnormal Operation of Air Exhaust VVT

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function, Digital Multimeter, and

Correct Circuit Diagram)

Description about Malfunction Cause: The actual position deviates greatly from the target position of VVT.

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

P-CODE Present P-CODE Present

P000B

Maintenance tips:

The malfunction has been confirmed, and the

following problems may possibly exist

1) VVT is jammed at certain position of large

opening;

2) VVT is jammed near the block position;

3） VVT runs very slowly, resulting in big

deviation between target and actual position.

Maintenance tips:

Unstable idling speed or rough running of engine may

appear, please check VVT or replace it when

necessary.

General Precautions of EFI System Maintenance

F-7

3. P0010: Malfunction of Air Intake VVT Open Circuit

P2088: Malfunction of Air Intake VVT Short Circuit to Ground

P2089: Malfunction of Air Intake VVT Short Circuit to Power Supply

Schematic Circuit:

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function, Digital Multimeter, and

Correct Circuit Diagram)

Description about Malfunction Cause: It is VVT circuit malfunction, which is commonly caused by

VVT’s open circuit, short circuit to ground or short circuit to power supply.

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present

P2088, P2089 P0010, P2088, P2089 P2088, P2089 P0010, P2088, P2089

Maintenance tips:

Circuit malfunction

Maintenance tips:

1. Please check wire harness between VVT and ECU

Pin 48# for open circuit, short circuit to ground or

short circuit to power supply;

2. Unstable idling speed or rough running of engine

may appear.

4. P0012: Improper Block Position of Air Intake VVT

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function, Digital Multimeter, and

Correct Circuit Diagram)

Description about Malfunction Cause: VVT is jammed at certain position of large opening and cannot

return to the block position.

Main relay

General Precautions of EFI System Maintenance

F-8

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

P-CODE Present P-CODE Present

P0012

Maintenance tips:

VVT hardware malfunction

Maintenance tips:

1. Unstable idling speed or rough running of engine

may appear.

2. Please check VVT mechanism and replace it

when necessary.

5. P0013: Malfunction of Air Exhaust VVT Open Circuit

P2090: Malfunction of Air Exhaust VVT Short Circuit to Ground

P2091: Malfunction of Air Exhaust VVT Short Circuit to Power Supply

Schematic Circuit:

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function, Digital Multimeter, and

Correct Circuit Diagram)

Description about Malfunction Cause: It is VVT circuit malfunction, which is commonly caused by

VVT’s open circuit, short circuit to ground or short circuit to power supply.

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present

P2090, P2091 P0013, P2090, P2091 P2090, P2091 P0013, P2090, P2091

Maintenance tips:

Circuit malfunction

Maintenance tips:

1. Please check wire harness between VVT and ECU

Pin 28# for open circuit, short circuit to ground or

short circuit to power supply;

2. Unstable idling speed or rough running of engine

may appear.

Main relay

General Precautions of EFI System Maintenance

F-9

6. P0015: Improper Block Position of Air Intake VVT

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function, Digital Multimeter, and

Correct Circuit Diagram)

Description about Malfunction Cause: VVT is jammed at certain position of large opening and cannot

return to the block position.

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

P-CODE Present P-CODE Present

P0015

Maintenance tips:

VVT hardware malfunction

Maintenance tips:

1. Unstable idling speed or rough running of engine

may appear.

2. Please check VVT mechanism and replace it

when necessary.

7. P0016 Improper Relative Position of Crankshaft and Air Intake Camshaft

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function, Digital Multimeter, and

Correct Circuit Diagram)

Description about Malfunction Cause: Large deviation of relative mounting position between

crankshaft and camshaft or skidding in belt.

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present

Lighting P0016 Lighting P0016

Maintenance tips:

1) Large deviation between relative actual and

target mounting position of crankshaft and

camshaft;

2) Skidding of belt of camshaft and crankshaft;

3) VVT is jammed at certain position and cannot

return to the block position;

4) Low control precision of OCV valve.

Check the relative position between camshaft and

crankshaft.

Maintenance tips:

1. Replace air intake VVT;

2. Replace camshaft.

General Precautions of EFI System Maintenance

F-10

8. P0017 Improper Relative Position of Crankshaft and Air Exhaust Camshaft

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function, Digital Multimeter, and

Correct Circuit Diagram)

Description about Malfunction Cause: Large deviation of relative mounting position between crankshaft

and camshaft or skidding in belt.

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present

Lighting P0017 Lighting P0017

Maintenance tips:

1). Large deviation between relative actual and

target mounting position of crankshaft and

camshaft;

2). Skidding of belt of camshaft and crankshaft;

3). VVT is jammed at certain position and cannot

return to the block position;

4). Low control precision of OCV valve.

Check the relative position between camshaft

and crankshaft.

Maintenance tips:

1. Replace air exhaust VVT;

2. Replace camshaft.

9. P0030 Upstream Oxygen Sensor Heating Control Circuit Open

Description about Malfunction Cause:

After engine has been started, the voltage of upstream oxygen sensor heating circuit is to be measured by the

circuit control module inside ECU, and when the voltage complies with the voltage in the mode of open

circuit, it is determined to be the heating circuit of upstream oxygen sensor in open circuit.

Schematic Circuit:

Main relay

General Precautions of EFI System Maintenance

F-11

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function, Digital Multimeter, and

Correct Circuit Diagram)

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present

P0030 P0030

Maintenance tips:

The malfunction has been confirmed, and the

following problems may possibly exist

1) The circuit connected to the Pin 26# of

ECU and the Pin C# of upstream oxygen

sensor in open circuit

2) The circuit for Pin D# of upstream oxygen

sensor connected to main relay in open

circuit

3) The Pin C# and the Pin D# of upstream

oxygen sensor in open circuit

Maintenance tips:

The malfunction is not ultimately confirmed and it may

possibly be a random malfunction. Inspect the following

items:

1) Measure the electric resistance in the line between

the Pin 26# for connector of ECU and the Pin B# of

upstream oxygen sensor.

2) Measure the electric resistance from the Pin C# of

upstream oxygen sensor to the main relay.

3) Measure the electric resistance between the Pin C#

and the Pin D# of upstream oxygen sensor.

4) Inspect whether or not the contact for the connector

of oxygen sensor and the connector of ECU is under

good condition.

10. P0031 Upstream Oxygen Sensor Heating Control Circuit Short to Ground

Description about Malfunction Cause:

After engine has been started, the voltage of upstream oxygen sensor heating circuit is to be measured by the

circuit control module inside ECU, and when the voltage complies with the voltage in the mode of short to

ground, it is determined to be the heating circuit of upstream oxygen sensor short to ground.

Schematic Circuit:

Main relay

General Precautions of EFI System Maintenance

F-12

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function, Digital Multimeter, and

Correct Circuit Diagram)

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present

P0031 P0031

Maintenance tips:

The malfunction has been confirmed, and the

following problems may possibly exist

1) The circuit connected to the Pin 26# of ECU

short to ground

Maintenance tips:

The malfunction is not ultimately confirmed and it

may possibly be a random malfunction. Inspect the

following items:

1) Measure whether or not the electric resistance for

the Pin 26# of ECU is normal.

11. P0032 Upstream Oxygen Sensor Heating Control Circuit Short to Power Supply

Description about Malfunction Cause:

After engine has been started, the voltage of upstream oxygen sensor heating circuit is to be measured by the

circuit control module inside ECU, and when the voltage complies with the voltage in the mode of short to

power supply, it is determined to be the heating circuit of upstream oxygen sensor short to power supply.

Schematic Circuit:

Main relay

General Precautions of EFI System Maintenance

F-13

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function, Digital Multimeter, and

Correct Circuit Diagram)

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present

P0032 P0032

Maintenance tips:

The malfunction has been confirmed, and the

following problems may possibly exist

1) The circuit connected to the Pin 26# of ECU and

the circuit of the Pin D# for upstream oxygen

sensor in short circuit

2) The circuit connected to the Pin 26# of ECU and

the other power supply circuit in short circuit

Maintenance tips:

The malfunction is not ultimately confirmed and it

may possibly be a random malfunction. Inspect the

following items:

1) Measure whether or not the voltage for the Pin

26# of ECU is normal.

2) Measure the electric resistance of the circuit

between the Pin 26# of ECU and the Pin D# of

upstream oxygen sensor.

12. P0036 Downstream Oxygen Sensor Heating Control Circuit Open

Description about Malfunction Cause:

After engine has been started, the voltage of heating circuit for downstream oxygen sensor is to be measured

by the circuit control module inside ECU, and when the voltage complies with the voltage in the mode of

open circuit, it is determined to be the heating circuit of downstream oxygen sensor in open circuit.

Schematic Circuit:

Main relay

General Precautions of EFI System Maintenance

F-14

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function, Digital Multimeter, and

Correct Circuit Diagram)

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present

P0036 P0036

Maintenance tips:

The malfunction has been confirmed, and the

following problems may possibly exist

1) the circuit connected to the Pin 29# of ECU

and the Pin D# of downstream oxygen

sensor in open circuit

2) The circuit for the Pin C# of downstream

oxygen sensor connected to the main relay in

open circuit

3) The Pin C# and the Pin D# of downstream

oxygen sensor in open circuit

Maintenance tips:

The malfunction is not ultimately confirmed and it may

possibly be a random malfunction. Inspect the following

items:

1) Measure the electric resistance of the line between

the Pin 29# for connector of ECU and the Pin D# of

downstream oxygen sensor.

2) Measure the electric resistance between the Pin C#

of downstream oxygen sensor connected to the main

relay.

3) Measure the electric resistance between the Pin C#

and the Pin D# of the downstream oxygen sensor.

4) Inspect whether or not the contact for the connector

of oxygen sensor and the connector of ECU is under

good condition.

13. P0037 Downstream Oxygen Sensor Heating Control Circuit Short to Ground

Description about Malfunction Cause:

After engine has been started, the voltage of heating circuit for downstream oxygen sensor is to be measured

by the circuit control module inside ECU, and when the voltage complies with the voltage in the mode of

short to ground, it is determined to be the heating circuit of downstream oxygen sensor short to ground.

Schematic Circuit:

Malfunction Diagnostic Guide:

Main relay

General Precautions of EFI System Maintenance

F-15

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function, Digital Multimeter, and

Correct Circuit Diagram)

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present

P0037

Maintenance tips:

The malfunction has been confirmed, and the

following problems may possibly exist

1) The circuit connected to the Pin 29# of ECU

short to ground

Maintenance tips:

The malfunction is not ultimately confirmed and it

may possibly be a random malfunction. Inspect the

following items:

1) Measure whether or not the electric resistance

for the Pin 28# of ECU to ground is normal.

14. P0038 Downstream Oxygen Sensor Heating Control Circuit Short to Power Supply

Description about Malfunction Cause:

After engine has been started, the voltage of heating circuit for downstream oxygen sensor is to be measured

by the circuit control module inside ECU, and when the voltage complies with the voltage in the mode of

short to power supply, it is determined to be the heating circuit of downstream oxygen sensor short to power

supply.

Schematic Circuit:

Main relay

General Precautions of EFI System Maintenance

F-16

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function, Digital Multimeter, and

Correct Circuit Diagram)

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present

P0038 P0038

Maintenance tips:

The malfunction has been confirmed, and the

following problems may possibly exist

1) The circuit connected to the Pin 29# of ECU and

the circuit of Pin C# for downstream oxygen

sensor in short circuit

2) The circuit connected to the Pin 29# of ECU and

the other power supply circuit in short circuit

Maintenance tips:

The malfunction is not ultimately confirmed and it

may possibly be a random malfunction. Inspect the

following items:

1) Measure whether or not the voltage for the Pin

29# of ECU is normal.

2) Measure the electric resistance of the circuit

between the Pin 28# of ECU and the Pin C# of

downstream oxygen sensor.

15. P0053 Upstream Oxygen Sensor Heating Internal Resistance Irrational

Description about Malfunction Cause:

Heater of oxygen sensor is diagnosed through monitoring over the internal resistance of heater. The internal

resistance of heater is determined by temperature of ceramic, while the temperature of ceramic is subjected to

the impact of waste gas temperature in the heater and the catalyst converter. The diagnosis is performed

through comparison between the measurement value and the reference value (related to heater power and the

temperature in catalyst converter) for the internal resistance of ceramic. It will be determined to be heating

malfunction if the measurement value exceeds the reference value or malfunction exists with the heater at

power level.

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function)

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present

P0053

Maintenance tips:

The malfunction has been confirmed, and the

following problems may possibly exist

1) The heating function of downstream oxygen

sensor failed, and the oxygen sensor to be

replaced.

2) Check for proper connection of wire harness.

Maintenance tips:

The malfunction has not been finally confirmed.

Please wait for system to fulfill diagnosis.。

General Precautions of EFI System Maintenance

F-17

16. P0054 Downstream Oxygen Sensor Internal Resistance Irrational

Description about Malfunction Cause:

Heater of oxygen sensor is diagnosed through monitoring over the internal resistance of heater. The internal

resistance of heater is determined by temperature of ceramic, while the temperature of ceramic is subjected to

the impact of waste gas temperature in the heater and the catalyst converter. The diagnosis is performed

through comparison between the measurement value and the reference value (related to heater efficiency and

the temperature in catalyst converter) for the internal resistance of ceramic. It will be determined to be heating

malfunction if the measurement value exceeds the reference value or malfunction exists with the heater at

power level.

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function)

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present

P0054

Maintenance tips:

The malfunction has been confirmed, and the

following problems may possibly exist

1) The heating function of downstream oxygen

sensor failed, and the oxygen sensor to be

replaced.

Maintenance tips:

The malfunction has not been finally confirmed.

Please wait for system to fulfill diagnosis.。

17. P0101 Air Flow Meter Sensor Signal Irrational

Description about Malfunction Cause:

The signal of air flow meter sensor is obtained by the transformation of temperature difference signal to

voltage signal. After the start of engine, if through comparison of the continuously checked voltage signal of

air flow meter sensor with the theoretical value stored in ECU, the voltage signal is not within the theoretical

value range, signal irrational is determined by the diagnostic system.

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function)

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present

P0054 P0054

Maintenance tips:

The malfunction has been confirmed, and the

following problems may possibly exist

The air flow meter failed, and the air flow meter to be

replaced

Maintenance tips:

The malfunction has not been finally confirmed.

Please wait for system to fulfill diagnosis.。

General Precautions of EFI System Maintenance

F-18

18. P0102 Air Flow Meter Sensor Voltage Too Low

Description about Malfunction Cause:

The signal of air flow meter sensor is obtained by the transformation of temperature difference signal to

voltage signal. After the start of engine, if the continuously checked voltage signal of air flow meter sensor is

below the threshold value, low voltage failure is determined by the system.

Schematic Circuit:

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function)

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present

P0102

Maintenance tips:

The malfunction has been confirmed, and the

following problems may possibly exist

1) Short circuit between Pin 37# and Pin 17# of

ECU.

2) Circuit connected to Pin 37# of ECU short

circuited to ground.

Maintenance tips:

The malfunction has not been finally confirmed.

Please wait for system to fulfill diagnosis.。

1) Measure the electric resistance of the circuit

between the Pin 37# of ECU and the Pin 17# of

ECU.

2) Measure the electric resistance of circuit

between Pin 37# of ECU and ground.

Main relay

General Precautions of EFI System Maintenance

F-19

19. P0103 Air Flow Meter Sensor Voltage Signal Too High

Description about Malfunction Cause:

The signal of air flow meter sensor is obtained by the transformation of temperature difference signal to

voltage signal. After the start of engine, if the continuously checked voltage signal of air flow meter sensor is

above the threshold value, high voltage failure is determined by the system.

Schematic Circuit:

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function)

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present

P0102

Maintenance tips:

The malfunction has been confirmed, and the

following problems may possibly exist

1) The circuit connected to the Pin 37# of ECU and

the circuit of the Pin 33# of ECU in short circuit

2) The circuit connected to the Pin 37# of ECU and

the other power supply short circuit

3) The circuit connected to the Pin 37# of ECU and

the main relay short circuit

Maintenance tips:

The malfunction has not been finally confirmed.

Please wait for system to fulfill diagnosis.。

1) Measure the electric resistance of the circuit

between the Pin 37# of ECU and the Pin 33# of

ECU.

2) Measure the electric resistance of the circuit

between the Pin 37# of ECU and the other

power supply.

3) Measure the electric resistance of the circuit

between the Pin 37# of ECU and the main relay.

20. P0112 Intake Temperature Sensor Signal Voltage Over-Low

Description about Malfunction Cause:

After engine has been started, ECU performs continuous monitoring over the intake temperature, and it will

be determined to be circuit of intake temperature sensor short to ground, if it is found that the engine intake

temperature exceeds the system set lower limit value.

Schematic Circuit:

Main relay

General Precautions of EFI System Maintenance

F-20

Malfunction Diagnostic Guide:

Required Equipment: (Diagnostic Instrument with EOBD Diagnostic Function, Digital Multimeter, and

Correct Circuit Diagram)

Step I: Use diagnostic instrument to read the malfunction information

Read Result I Read Result II

MIL Lamp On P-CODE Present MIL Lamp Off P-CODE Present

P0112

Maintenance tips:

The malfunction has been confirmed, and the

following problems may possibly exist

1) The circuit connected to the Pin 45# of ECU and

the circuit for the Pin 17# of ECU in short

circuit

2) The circuit connected to the Pin 42# of ECU and

the ground in short circuit

Maintenance tips:

The malfunction is not ultimately confirmed and it

may possibly be a random malfunction. Inspect the

following items:

1) Measure the electric resistance of the circuit

between the Pin 42# of ECU and the Pin 17# of

ECU.

2) Measure the electric resistance between the Pin

42 of ECU and the ground.

21. P0113 Intake Temperature Sensor Signal Voltage too High

Description about Malfunction Cause:

After engine has been started, ECU performs continuous monitoring over intake temperature, and it will be

determined to be the circuit of intake temperature sensor short to power supply if it is found that the engine

intake temperature exceeds the system set upper limit value.

Schematic Circuit:

Main relay

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Haima 7 User manual

Haima 7 User manual

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