INTRODUCTION - DIESEL FUEL INJECTION SYSTEM

1.9 JTD 16v

SPECIFICATIONS

FUNCTION

The EDC-16C39 Common Rail system is a high pressure electronic injection circuit for fast, direct injection diesel engines.

Its main features are:

• availability of high injection pressure (up to 1600 bar);

  possibility of modulating these pressures between 150 bar up to the maximum operating pressure of 1600 bar, independently of the

  rotation speed and engine load;

  ability to work at high engine rpms (up to 5000 rpm in full load conditions);

  precision injection control (injection advance and duration);

  reduced fuel consumption;

  reduced emissions.

The system''s main functions are as follows:

• fuel temperature control;

  engine coolant temperature control;

  control of amount of fuel injected;

  idle speed control;

  fuel cut-off during over-run;

  cylinder balance control from idle speed up to 3500 rpm;

  control of anti-judder function;

  control of exhaust fumes during acceleration;

  exhaust gas recirculation control (E.G.R.);

  maximum torque limit control;

  maximum speed limit control;

  glowheater plugs control;

  control of climate control system activation (where fitted);

  auxiliary fuel pump control;

  cylinder position control;

  main and multiple injection advance control;

  closed cycle injection pressure control;

  electrical balance control;

  supercharging pressure control;

  IMA injector calibration.

APPLIES TO VERSIONS WITH: EURO 4, LAMBDA SENSOR

1. Auxiliary fuel pump

2. Fuel filter

3. Fuel return manifold

4. Pressure pump

5. Pressure regulator on pump

6. Turbocharging sensor

7. Pressure regulator on rail

8. Pressure sensor

9. Rail

10. Throttle body

11. EGR solenoid

12. Oil level sensor

13. Timing sensor

14. Glowheater plug

15. Turbo vane actuator control solenoid

16. Air flow meter

17. Rpm sensor

18. Water temperature sensor

19. Minimum oil pressure switch

20. Lambda sensor

21. Main catalytic converter

22. Engine wiring

23. Pedal assembly

24. Diagnostic connector

25. Injection control unit

26. Vehicle wiring

27. Swirl throttle control actuator

APPLIES TO VERSIONS WITH: EURO 4, DPF

1. Auxiliary fuel pump

2. Fuel filter

3. Fuel return manifold

4. Pressure pump

5. Pressure regulator on pump

6. Turbocharging sensor

7. Pressure regulator on rail

8. Pressure sensor

9. Rail

10. Throttle body

11. EGR solenoid

12. Oil level sensor

13. Timing sensor

14. Glowheater plug

15. Turbo vane actuator control solenoid

16. Air flow meter

17. Rpm sensor

18. Water temperature sensor

19. Minimum oil pressure switch

20. Thermocouple downstream of catalytic converter

21. Thermocouple on DPF

22. Differential pressure sensor

23. Trap filter (DPF)

24. Pedal assembly

25. Diagnostic connector

26. Injection control unit

27. Vehicle wiring

28. Engine wiring

29. Swirl throttle control actuator

OPERATION

Operating strategies

Introduction

The Common Rail system makes it possible to carry out a pre-injection (pilot injection) before T.D.C. This has the advantage of reducing the pressure shift in the combustion chamber, thus reducing the combustion noise typical of direct injection engines.

The control unit manages the quantity of fuel injected, regulating the line pressure and injection times.

The control unit processes the following information in order to control the quantity of fuel to inject:

• engine rpm;
• coolant temperature;
• turbocharging pressure;
• air temperature;
• intake air quantity;
• battery voltage;
• diesel pressure;
• accelerator pedal position.

Diagram showing information entering/leaving the control unit

1, Auxiliary fuel pump

2, Turbocharging pressure control solenoid

3, Air conditioner compressor

4, EGR solenoid

5, Rev counter (via CAN)

6, Electric fans

7, Glowheater plug control unit

8, Accelerator pedal potentiometer

9, Brake - clutch pedal switch

10, Fuel pressure sensor

11, Air flow meter

12, Coolant temperature sensor

13, Fuel temperature sensor

14, Cruise Control (where fitted) (via CAN)

15, Excess pressure sensor

16, Timing sensor

17, Rpm sensor

18, Speedometer (via CAN)

19, Battery

20, FIAT CODE (via CAN)

21, Diagnostic socket (via CAN)

22, Pressure regulator

23, Injectors

24, Glowheater plugs

25, Throttle solenoid (on throttle body)

26, Glowheater plug warning light (via CAN)

27, Injection warning light (via CAN)

28, Water max temperature warning light (via CAN)

29, Water in fuel warning light (via CAN)

Self-diagnosis

The control unit self-diagnostic system checks the signals coming from the sensors and compares them with the permitted limits.

FAULT SIGNALS DISPLAYED DURING START UP:

• warning light stays on for 4 seconds to indicate test stage;
• the warning light goes out after 4 seconds to indicate there are no faults in components that could alter values imposed by pollution control regulations;
• if the warning light is still on after 4 seconds, this indicates a fault.

FAULT SIGNALS DISPLAYED DURING OPERATION:

• warning light on indicates a fault;
• warning light off indicates there are no faults with components that could alter values imposed by pollution control regulations.

RECOVERY

The control unit defines the recovery settings on each specific occasion according to which components are faulty.

The recovery parameters are managed by non-faulty components.

Fiat code recognition

The moment the control unit receives the ignition MAR signal, it converses with the body computer (FIAT CODE function) to obtain the go-ahead for starting.

Engine coolant temperature control

When the engine coolant temperature is above 105°C, the control unit:

• reduces the quantity of fuel injected (reduces engine power);
• controls the cooling fans;
• switches the coolant temperature warning light on.

Control of the amount of fuel injected

The control unit compares the signals coming from the sensors to the stored values, and:

• controls the pressure regulator;
• alters the "pilot" injection time up to 3000 rpm;
• modulates the "main" injection time.

Idle speed check

The control unit processes the signals coming from the various sensors, regulates the quantity of fuel injected and:

• controls the pressure regulator;
• modulates the injector injection times.

Within certain limits the speed is dependent on battery voltage.

Fuel cut-off during over-run

When the accelerator pedal is released, the control unit implements the following strategies:

• cuts off the supply to the injectors;
• partly reactivates the supply to the injectors before the idle speed is reached;
• controls the fuel pressure regulator.

Idle cylinder balance check

According to the signals received from the sensors, the control unit monitors torque at idle speed to ensure it is regular:

• modulates the quantity of fuel injected into the individual injectors (injection time).

Anti-judder check

The control unit processes the signals received by the various sensors and corrects the quantity of fuel injected in order to improve driveability and reduce jerking whilst driving by means of:

• the pressure regulator;
• injector opening time.

Control of exhaust fumes during acceleration

In order to restrict exhaust fumes during fast transitions, the control unit analyses signals received from the air flow meter and the engine speed and then limits the amount of fuel injected by means of:

• the pressure regulator
• the injector injection time.

Exhaust gas recirculation (e.g.r.) control

In accordance with pollution control legislation, on the basis of the engine load and the signal from the accelerator pedal potentiometer, the control unit limits the quantity of intake air, implementing the partial intake of exhaust gases, by:

• adjusting the E.G.R. valve opening.

Maximum torque limit control

The control unit uses mapped values plotted against rpm to calculate the following:

• the torque limit;
• the permitted level of fumes (limit).

It compares these minimum values with other parameters and corrects them:

• coolant temperature;
• engine rpm;
• vehicle speed,

and controls the quantity of fuel to be injected (pressure regulator - injectors).

Maximum speed limit control

Depending on the rpm, the control unit implements two intervention strategies:

• at 5000 rpm it cuts off the fuel, reducing the line pressure;
• beyond 5400 rpm it deactivates the auxiliary pump and the injectors.

Glowheater plug check

The injection control unit, during the following stages:

• start-up;
• post start-up
• times the operation of the glow plug control unit on the basis of engine temperature.

Air conditioning system start-up check

The control unit operates the air conditioning compressor:

• activating/de-activating it when the correct switch is pressed;
• switching it off temporarily (about 6 secs) in the event of strong acceleration or a request for maximum power.

Auxiliary fuel pump check

Irrespective of the rpm, the control unit:

• supplies the auxiliary fuel pump when the ignition is switched to MAR;
• cuts off the auxiliary pump supply if the engine is not started within a few seconds.

Cylinder position check

During each revolution of the engine the control unit recognises which cylinder is in the combustion stroke and controls the injection sequence within the appropriate cylinder.

Main and pilot injection advance check

According to the signals coming from the various sensors, including the absolute pressure sensor built into the control unit itself, the latter determines the optimum injection point, according to an internal map, based on driving comfort and emission limits.

Injection pressure closed loop check

The control unit manages the regulator to produce optimum line pressure according to engine load, which is determined by processing signals from the various sensors.

Electrical balance check

The control unit modulates idle speed according to the battery voltage and:

• increases the injectors'' injection times;
• modulates the line pressure.

Variable geometry turbine vgt check (120 bhp version)

The control unit processes the signal from the turbocharging sensor at various engine operating speeds, determines the quantity of fuel to inject and:

• controls the pressure regulator;
• modulates the injection time;
• regulates the turbine geometry to ensure optimum performance under all operating conditions.

Fan control

Depending on the temperature of the engine coolant and the pressure of the coolant in the air conditioning system, the control unit controls:

• fan activation at first or second speeds.

Throttle closing check at shut-down

In order to prevent the engine juddering when it is switched off, the control unit immediately closes the inlet throttle. The throttle remains open in all other operating conditions.

Cruise control system check (where fitted)

Depending on the position of the cruise control lever, the control unit directly manages the quantity of fuel injected, in order to control and maintain the vehicle speed memorised.

A warning light in the dashboard activated by the control unit indicates system operation or deactivation status.

The cruise control is temporarily disabled:

• by operating the brake,
• by operating the clutch;
• by the recall button, which restores the stored speed.

The cruise control is not disabled when the accelerator is pressed (e.g. to overtake) and automatically restores the vehicle to the set speed as soon as the accelerator is released.

The ASR function (antispin) takes precedence over cruise control for safety reasons.

1.9 JTD 8v

SPECIFICATIONS

FUNCTION

The EDC-16C39 Common Rail system is a high pressure electronic injection circuit for fast, direct-injection diesel engines.

Its main features are:

• availability of high injection pressure (up to 1600 bar);

  possibility of modulating these pressures between 150 bar up to the maximum operating pressure of 1600 bar, independently of the

  rotation speed and engine load;

  ability to work at high engine rpms (up to 5000 rpm in full load conditions);

  precision injection control (injection advance and duration);

  reduced fuel consumption;

  reduced emissions.

The main system functions are as follows:

• fuel temperature control;

  engine coolant temperature control;

  control of amount of fuel injected;

  idle speed control;

  fuel cut-off during over-run;

  cylinder balance control from idle speed up to 3500 rpm;

  control of anti-judder function;

  control of exhaust fumes during acceleration;

  exhaust gas recirculation control (E.G.R.);

  maximum torque limit control;

  maximum speed limit control;

  glowheater plug control;

  control of climate control system activation (where fitted);

  auxiliary fuel pump control;

  cylinder position control;

  main and multiple injection advance control;

  closed cycle injection pressure control;

  electrical balance control;

  turbocharging pressure control;

  IMA injector calibration.

APPLIES TO VERSIONS WITH: EURO 4, LAMBDA SENSOR

• 1 Auxiliary fuel pump
• 2 Fuel filter
• 3 Fuel return manifold
• 4 Pressure pump
• 5 Pressure regulator on pump
• 6 Turbocharging sensor
• 7 Pressure regulator on rail
• 8 Pressure sensor
• 9 Rail
• 10 Throttle body
• 11 E.G.R. solenoid
• 12 Oil level sensor
• 13 Timing sensor
• 14 Glowheater plug
• 15 Turbo vane actuator control solenoid
• 16 Air flow meter
• 17 Rpm sensor
• 18 Water temperature sensor
• 19 Minimum oil pressure switch
• 20 Lambda sensor on preconverter
• 21 Main catalytic converter
• 22 Engine wiring
• 23 Pedal unit
• 24 Diagnostic connector
• 25 Injection control unit
• 26 Vehicle wiring

APPLIES TO VERSIONS WITH: EURO 4, DPF

• 1 Auxiliary fuel pump
• 2 Fuel filter
• 3 Fuel return manifold
• 4 Pressure pump
• 5 Pressure regulator on pump
• 6 Turbocharging sensor
• 7 Pressure regulator on rail
• 8 Pressure sensor
• 9 Rail
• 10 Throttle body
• 11 E.G.R. solenoid
• 12 Oil level sensor
• 13 Timing sensor
• 14 Glowheater plug
• 15 Turbo vane actuator control solenoid
• 16 Air flow meter
• 17 Rpm sensor
• 18 Water temperature sensor
• 19 Minimum oil pressure switch
• 20 Lambda sensor downstream of the catalytic converter
• 21 Lambda sensor downstream of the trap filter (DPF)
• 22 Differential pressure sensor
• 23 Trap filter (DPF)
• 24 Pedal assembly
• 25 Diagnostic connector
• 26 Injection control unit
• 27 Vehicle wiring
• 28 Engine wiring

OPERATION

Operating strategies

Introduction

The Common Rail system makes it possible to carry out a pre-injection (pilot injection) before T.D.C. This has the advantage of reducing the pressure shift in the combustion chamber, thus reducing the combustion noise typical of direct injection engines.

The control unit controls the quantity of fuel injected, regulating the line pressure and injection times.

The control unit processes the following information in order to control the quantity of fuel to inject:

• engine rpm;
• coolant temperature;
• turbocharging pressure;
• air temperature;
• intake air quantity;
• battery voltage;
• diesel pressure;
• accelerator pedal position.

Diagram showing information entering/leaving the control unit

1, Auxiliary fuel pump

2, Turbocharging pressure control solenoid

3, Air conditioner compressor

4, EGR solenoid

5, Rev counter (via CAN)

6, Electric fans

7, Glowheater plug control unit

8, Accelerator pedal potentiometer

9, Brake - clutch pedal switch

10, Fuel pressure sensor

11, Air flow meter

12, Coolant temperature sensor

13, Fuel temperature sensor

14, Cruise Control (where fitted) (via CAN)

15, Excess pressure sensor

16, Timing sensor

17, Rpm sensor

18, Speedometer (via CAN)

19, Battery

20, FIAT CODE (via CAN)

21, Diagnostic socket (via CAN)

22, Pressure regulator

23, Injectors

24, Glowheater plugs

25, Throttle solenoid (on throttle body)

26, Glowheater plug warning light (via CAN)

27, Injection warning light (via CAN)

28, Water max temperature warning light (via CAN)

29, Water in fuel warning light (via CAN)

Self-diagnosis

The control unit self-diagnostic system checks the signals coming from the sensors and compares them with the permitted limits.

FAULT SIGNALS DISPLAYED DURING START UP:

• warning light stays on for 4 seconds to indicate test stage;
• the warning light goes out after 4 seconds to indicate there are no faults in components that could alter values imposed by pollution control regulations;
• if the warning light is still on after 4 seconds, this indicates a fault.

FAULT SIGNALS DISPLAYED DURING OPERATION:

• warning light on indicates a fault;
• warning light off indicates there are no faults with components that could alter values imposed by pollution control regulations.

RECOVERY

The control unit defines the recovery settings on each specific occasion according to which components are faulty.

The recovery parameters are managed by non-faulty components.

Fiat code recognition

The moment the control unit receives the ignition MAR signal, it converses with the body computer (FIAT CODE function) to obtain the go-ahead for start-up.

Engine coolant temperature control

When the engine coolant temperature is above 105°C, the control unit:

• reduces the quantity of fuel injected (reduces engine power);
• controls the cooling fans;
• switches the coolant temperature warning light on.

Control of the amount of fuel injected

The control unit compares the signals coming from the sensors to the stored values, and:

• controls the pressure regulator;
• alters the "pilot" injection time up to 3000 rpm;
• modulates the "main" injection time.

Idle speed check

The control unit processes the signals coming from the various sensors, regulates the quantity of fuel injected and:

• controls the pressure regulator;
• modulates the injector injection times.

Within certain limits the speed is dependent on battery voltage.

Fuel cut-off during over-run

When the accelerator pedal is released, the control unit implements the following strategies:

• cuts off the supply to the injectors;
• partly reactivates the supply to the injectors before the idle speed is reached;
• controls the fuel pressure regulator.

Idle cylinder balance check

According to the signals received from the sensors, the control unit monitors torque at idle speed to ensure it is regular and

• modulates the quantity of fuel injected into the individual injectors (injection time).

Anti-judder check

The control unit processes the signals received by the various sensors and corrects the quantity of fuel injected in order to improve driveability and reduce jerking whilst driving by means of:

• the pressure regulator;
• injector opening time.

Exhaust fume control during acceleration

In order to restrict exhaust fumes during fast transitions, the control unit limits the amount of fuel injected according to signals received from the air flow meter and the engine speed, by means of:

• the pressure regulator
• the injector injection time.

Exhaust gas recirculation (e.g.r.) control

In accordance with pollution control legislation, on the basis of the engine load and the signal from the accelerator pedal potentiometer, the control unit limits the quantity of intake air, implementing the partial intake of exhaust gases, by:

• adjusting the E.G.R. valve opening.

Maximum torque limit control

The control unit uses mapped values plotted against rpm to calculate the following:

• the torque limit;
• the permitted level of fumes (limit).

It compares these minimum values with other parameters and corrects them:

• coolant temperature;
• engine rpm;
• vehicle speed,

It also controls the quantity of fuel to be injected (pressure regulator - injectors).

Maximum speed limit control

Depending on the rpm, the control unit implements two intervention strategies:

• at 5000 rpm it cuts off the fuel, reducing the line pressure;
• beyond 5400 rpm, it deactivates the auxiliary pump and the injectors.

Glowheater plug check

The injection control unit, during the following stages:

• start-up;
• post start-up
• times the operation of the glowheater plug control unit on the basis of engine temperature.

Air conditioning system start-up check

The control unit operates the air conditioning compressor:

• activating/de-activating it when the correct switch is pressed;
• switching it off temporarily (about 6 secs) in the event of strong acceleration or a request for maximum power.

Auxiliary fuel pump check

Irrespective of the rpm, the control unit:

• supplies the auxiliary fuel pump when the key is turned to MAR;
• cuts off the auxiliary pump supply if the engine is not started within a few seconds.

Cylinder position check

During each revolution of the engine the control unit recognises which cylinder is in the combustion stroke and controls the injection sequence within the appropriate cylinder.

Main and pilot injection advance check

According to the signals coming from the various sensors, including the absolute pressure sensor built into the control unit itself, the latter determines the optimum injection point, according to an internal map, based on driving comfort and emission limits.

Injection pressure closed loop check

The control unit controls the regulator to produce optimum line pressure according to engine load, which is determined by processing signals from the various sensors.

Electrical balance check

The control unit modulates idle speed according to the battery voltage and:

• increases the injector injection times;
• modulates the line pressure.

Variable geometry turbine vgt check (120 bhp version)

The control unit processes the signal from the turbocharging sensor at various engine operating speeds, determines the quantity of fuel to inject and:

• controls the pressure regulator;
• modulates the injection time;
• regulates the turbine geometry to ensure optimum performance under all operating conditions.

Fan control

Depending on the temperature of the engine coolant and the pressure of the air conditioning system coolant, the control unit controls:

• fan activation at first or second speed.

Throttle closing check at shut-down

In order to prevent the engine juddering when it is switched off, the control unit immediately closes the inlet throttle. The throttle remains open in all other operating conditions.

Cruise control system check (where fitted)

Depending on the position of the cruise control lever, the control unit directly manages the quantity of fuel injected in order to control and maintain the vehicle speed which has been memorised.

A warning light on the dashboard, activated by the control unit, indicates system operation or deactivation status.

The cruise control is temporarily disabled:

• by operating the brake,
• by operating the clutch;
• when the recall button restores the memorised speed.

The cruise control is not disabled in the event of a request from the accelerator (e.g. to overtake) and automatically restores the vehicle to the set speed as soon as the accelerator is released.

The ASR function (antispin) takes precedence over cruise control for safety reasons.