EDC16C9 Engine Management System Opel Vectra C

The Z 19 DT OHC diesel engine and the Z 19 DTH DOHC diesel engine are equipped with the EDC16C9 engine management system. The Z 19 DT OHC diesel engine and the Z 19 DTH DOHC diesel engine have multijet injection like the previous Z 13 DT DOHC diesel engine.

Multijet injection makes extremely high demands of the engine management system.

The engine management system must continuously adjust the injection pattern, the number of injection operations and the injected quantity of fuel depending on the temperature, the load and the engine speed.

The EDC16C9 engine management system meets these multijet injection performance requirements.

The individual EDC16C9 engine management system components are described in more detail in the following chapters.

EDC16C9 I Component Overview

EDC16C9 Ii Component Overview

Multijet Injection System

Up to five injection operations per operating cycle are possible with Multijet injection. The injection operations are subdivided as follows:

• Pilot injection
• Pre-injection
• Main injection
• Post-injection
• Late injection

Pilot Injection

Pilot injection has the task of compensating for the engine warm-up phase.

Pilot injection is used up to an engine temperature of 60°. When this engine temperature is reached pilot injection stops and is not activated again until the engine temperature drops below 60°.

Pilot injection reduces noise emission considerably. The engine runs considerably quieter during cold starts and the warm-up phase when pilot injection is used.

Pre-Injection, Main Injection and Post-Injection

The main injection operation, which is the normal method that is used, has been subdivided into three individual injection operations that are oriented to engine requirements. Subdividing the main injection operation into pre-injection, main injection and post-injection makes the engine combustion extremely effective and low-emission.

These three injection operations allow the engine to supply fuel in a load-dependent and requirement-oriented way. The engine control unit receives the data that is needed to calculate the quantity of fuel from the relevant sensors in the engine.

Late Injection

Late injection only takes place in vehicles with a diesel particle filter. Additional fuel is injected into the gasses leaving the cylinder during the exhaust cycle.

The additional fuel that is injected far above the top dead centre of the piston is converted into heat at the two catalytic converters in the exhaust system, which drastically increases the temperature of the outflowing exhaust gas.

This exhaust gas temperature increase is needed to regenerate the diesel particle filter.

Late injection is not initiated until the engine control unit has evaluated the data from the sensors and calculated that the soiling level of the diesel particle filter has reached the maximum limit stored in the engine control unit.

Diesel Particle Filter Regeneration

All of the sensor data sent to the engine control unit is stored in the control unit and used to calculate a statistical value. The amount of diesel particle filter soiling can be calculated from this and regeneration triggered if necessary.

The amount of diesel particle filter soiling is also monitored by a differential pressure sensor at the exhaust system. The differential pressure sensor measures the pressure difference before and after the diesel particle filter.

The measured pressure difference provides an indication of the amount of diesel particle filter soiling.

A high degree of contamination reduces the permeability of the diesel particle filter. This creates higher pressure upstream of the diesel particle filter and lower pressure downstream of the filter.

If the pressure difference that is measured is too high, the engine control unit triggers regeneration.

The diesel particle filter cleaning interval is otherwise calculated using a statistical model stored in the control unit, which also uses the learned values stored in the control unit memory.

The engine control unit triggers diesel particle filter regeneration when the soiling level has reached 10% by volume of the diesel particle filter.

Diesel particle filter regeneration is triggered automatically by the engine control unit. It cannot be detected by the driver and is independent of the current operating conditions.

It is also possible to perform manual regeneration. Regeneration is triggered via the relevant menu in TECH2.

The relevant procedure can be found in the relevant description for working with TECH2.

Diesel Particle Filter Regeneration (Procedure)

The regeneration procedure is as follows:

The engine control unit shifts the fuel pre-injection, main injection and post-injection times in the direction of late. Pilot injection and late injection are also performed in order to achieve the maximum exhaust temperature increase. The diesel particle filter needs a temperature of at least 550°C for regeneration. The temperature at the DPF is monitored during generation.

When the necessary regeneration temperature of 550°C has been reached the soot particles that are in the diesel particle filter can be burned off. The regeneration phase can last up to 15 minutes depending on the operating conditions. After this time the soot particles in the diesel particle filter should have combusted.

If an above-average temperature increase is measured in the diesel particle filter during the regeneration phase, the regeneration process is aborted. Regeneration is then repeated again later.

If the required regeneration temperature of 550°C is not reached, the regeneration is assumed to have been unsuccessful and is repeated at the next opportunity. After diesel particle filter regeneration has been successfully completed, the learned value for the particle filter is reset in the control unit. The calculation of the next regeneration cycle is restarted. The value is not reset to 0% because it is assumed that the diesel particle filter contains residual ash particles.

More information on diesel particle filter regeneration can be found in the chapter entitled "Maintenance-free Diesel Particle Filter System (DPF)" in this brochure.

Zero Fuel Correction (Zfc)

Two different corrections are used for working out the injected fuel quantities as accurately as possible for the injectors:

1. IMA (QR code): IMA coding relates to a measurement that is made at the completion of injector manufacture. Each injector is measured in terms of a number of reference points. Deviations from the target value are stored in the IMA (QR) code. The quantity deviations of each individual injector are corrected in the control unit by reading in the code.

2. Zero fuel correction (ZFC): unlike IMA correction, in this case a correction is made depending on the service life of the injectors.

This correction is only made to the injection quantity presettings, since they are extremely small quantities.

ZFC works as follows: when the engine control unit detects the deceleration phase, a smaller quantity is injected at one injector. The change to the cyclic irregularity of the crankshaft pulley is measured. If there is no reaction, the injected quantity is successively increased until a minimal reaction occurs. This value is stored in the control module as an adaptation value for the individual injector (cylinder). The same procedure is repeated for the other injectors, after which the full adaptation process is complete. This may take place over a driving distance of up to 6000 km (depending on driving style).

This function ensures that the injectors provide even small injection quantities that are requested. Adaptation also takes place according to mileage, since the function is continuously adapted.

If the injectors are replaced the new injectors must be taught in.

The QR code that is marked on the injectors is required to do this. This contains information about the injectors' manufacturing tolerances.

Teaching in takes place using TECH2.

More information with regard to the QR code and injector replacement can be found in the chapter entitled "Common Rail Engine Injector Programming" in this brochure.

• Service: If the injectors are replaced, they must be taught into the engine control unit using TECH2. The injector programming procedure can be found in the relevant TECH2 work description.

Oxygen Regulation in Vehicles Without Diesel Particle Filters.

Oxygen regulation is a new function that has been introduced for the Z 19 DT OHC diesel engine and the Z 19 DTH DOHC diesel engine without diesel particle filter.

Like the petrol engine, the oxygen sensor is in the exhaust system (downstream of the turbocharger). The oxygen sensor that is used is a broadband sensor that is also in a position to reliably measure the residual oxygen content in the weak operating range (partial load operation I >1).

Unlike the petrol engine, control is not performed over the short term in accordance with the current combustion situation, but the oxygen sensor signal is used to correct long-term drifts of the determining hot film mass air flow sensor and injector components. This ensures that the Euro 4 emission limits are reliably adhered to.

The engine management system attempts to correct these oxygen value deviations via the EGR characteristic curve. If the oxygen value deviates, the EGR rate in the characteristic curve is corrected by this value until the required oxygen target value has been reached.

The correction characteristic curve has a total of 64 operating points. The information being received by the engine control unit is converted into new correction values at the end of a driving cycle whilst driving.

This is an extremely powerful system that only needs a distance of approximately 22 km to be driven to adapt all 64 operating points.

In vehicles without a diesel particle filter an oxygen sensor has been integrated in the exhaust pipe upstream of the underbonnet catalytic converter.

This oxygen sensor measures the residual oxygen content of the exhaust gas that is flowing past it. It is possible to quantify the efficiency of the combustion in the cylinder using the residual oxygen content in the exhaust. The measurements are used to calculate the exhaust gas recirculation rate.

This control loop makes it possible to adapt the exhaust gas recirculation rate extremely accurately to a wide range of operating conditions and reduce emissions as much as possible.

See following chapter for more information on the subject of exhaust gas recirculation.

O 2 Sensor Diagram

1. Oxygen signal in volts
2. Oxygen concentration in %

Exhaust Gas Recirculation Valve, Z 19 Dt OHC Diesel Engine and Z 19 Dth DOHC Diesel Engine

The exhaust gas recirculation system in the Z 19 DT OHC diesel engine and the Z 19 DTH DOHC diesel engine has an exhaust gas recirculation valve at the intake manifold.

The exhaust gas recirculation valve is electrically actuated by the engine control unit and allows the amount of exhaust gas that is introduced to be accurately controlled. The recirculated exhaust gas flows from the intake manifold via the exhaust gas recirculation pipe through an exhaust gas recirculation cooler.

The exhaust gas is led from the exhaust gas recirculation cooler to the exhaust gas recirculation valve via an exhaust gas recirculation pipe.

In the Z 19 DT OHC diesel engine the exhaust is led into the inlet manifold via the throttle valve module.

In the Z 19 DTH DOHC diesel engine the exhaust is led directly into the intake manifold. The exhaust is added to the fresh gasses that have been loaded into the turbocharger in the intake manifold.

The quantity of oxygen is reduced by means of controlled addition of recirculated exhaust gas to the fresh gasses. This reduces the combustion temperature in the combustion chamber and therefore reduces the concentration of nitrous oxide in the exhaust.

Overview of Exhaust Gas Recirculation Valves

I shows the exhaust gas recirculation valve of the Z 19 DT OHC diesel engine

II shows the exhaust gas recirculation valve of the Z 19 DTH DOHC diesel engine

1. 1. Exhaust gas recirculation pipe connection
2. 2. Connection to intake manifold
3. 3. Connection to throttle valve module

Mass Air Flow Meter

The mass air flow sensors have been continuously developed over the last few years, the main focus being on the robustness of the system.

This has increased the robustness of this component, which is still extremely sensitive. Following the introduction of membrane reinforcement (HFM5-C), the bypass (HFM5-CL) and finally the deflector grille (HFM5-Cl) for keeping out coarse dirt particles the HFM6 will now be deployed, which is extremely particle resistant, deflects water and is therefore less susceptible to problems.

The HFM6 has a newly-developed bypass with different design and functionality.

The most important new features of the HFM6 mass air flow sensor are:

1. 1. Integrated deflection bypass system
2. 2. Mass air flow meter characteristic curve evaluation

Integrated Deflection Bypass System

The new integrated deflection bypass system considerably reduces sensor element soiling.

The air flow produced by the special shape of the HFM6 duct system achieves a high degree of continuous dirt and water particle separation.

A large proportion of the inflowing air is diverted through the bypass system diversion channel together with the soiling. The smaller proportion of air containing an extremely small amount of soiling flows directly past the sensor through an additional flow channel. This considerably reduces the burdening of the sensor with dirt particles.

This system increases the service life considerably and ensures that the engine management system is provided with a continuous supply of reliable and consistent measurements.

Technology

The new HFM6 mass air flow sensor is another new technological feature.

For the first time, the engine control unit is being provided with information on the air throughput and the air temperature in the form of a digital frequency.

Depending on the quantity and temperature of the air that is flowing through, a square signal is generated and relayed to the engine control unit. This square signal is generated by en evaluation circuit integrated in the mass air flow sensor.

The frequency that is generated reflects the current air throughput. It is therefore dependent on the air throughput.

The frequency of the signal reduces as the air throughput increases.

1. Signal with high air throughput
2. Signal with low air throughput

Mass Air Flow Sensor Characteristic Curve

The characteristic curve of the HFM6 mass air flow sensor reflects the reduction of the frequency as the air throughput increases.

This signal is extremely important for the engine control unit. This information is the only way for the engine control unit to proportion fuel in accordance with the engine load situation.

1. Frequency Microseconds
2. Mass air flow m/m-max

Throttle Valve Module, Z 19 Dt OHC Diesel Engine and Z 19 Dth DOHC Diesel Engine

Two different throttle valve modules are used in the Z 19 DT OHC diesel engine and the Z 19 DTH DOHC diesel engine.

The main difference between them is that the connection for the exhaust gas recirculation pipe of the Z 19 DT OHC diesel engine throttle valve is located in the immediately proximity of the throttle valve module.

In the Z 19 DTH DOHC diesel engine the exhaust gas recirculation pipe connection is at the intake manifold.

However, the throttle valve modules operate in an almost identical way.

In both throttle valve modules the throttle valves are operated by an electronically actuated servo motor. During engine operation the throttle valve is 100% open in both engine variants.

The throttle valve is only there to prevent the engine from running on when the engine is turned off. The throttle valve is fully closed when the engine is switched off.

Exploded View of Z 19 Dt OHC Diesel Engine Throttle Valve Module

The diagram shows the installation location of the throttle valve module of a Z 19 DT OHC diesel engine. This engine also has an exhaust gas recirculation pipe attached to the throttle valve connecting piece.

It is fed by the exhaust gas recirculation pipe coming from the exhaust gas recirculation cooler.

1. 1. Throttle valve module
2. 2. Exhaust gas recirculation valve
3. 3. Exhaust gas recirculation pipe

Exploded View of Z 19 Dth DOHC Diesel Engine Throttle Valve Module

This diagram shows the installation location of the throttle valve module of a Z 19 DTH DOHC diesel engine. In this case the exhaust gas recirculation valve is attached directly to the intake manifold.

It is fed by the exhaust gas recirculation pipe coming from the exhaust gas recirculation cooler.

1. 1. Throttle valve module
2. 2. Exhaust gas recirculation valve
3. 3. Exhaust gas recirculation pipe

Component Replacement

There are several system-related procedures to follow when replacing individual engine management system components. For example, most engine management system components have to be taught into the control unit in order to adjust the new data. Maximum engine efficiency can only be ensured if this is done.

The table below contains a list of components with the relevant post-replacement work in order to provide a better explanation.

• Service: The following procedure must be followed when replacing an engine control unit or component.