User Manual

Chapter 12

BOSCH HDI EDC 15C2 INJECTION SYSTEM AND PARTICLE FILTER

IV - EXHAUST GAS RECYCLING REGULATION

SDI036C

3 4

1 - Air flowmeter

2 - Engine speed sensor

3 - Injection ECU

4 - Exhaust gas recycling valve (EGR)

5 - Throttle housing (EGR)

6 - Throttle housing control electrovalve (EGR)

7 - Recycling regulation electrovalve (EGR)

Exhaust gas recycling is of progressive type and is controlled by a cartographic map.

Role of the injection ECU depending on the information received (exhaust gas

recycling rate determined in the cartographic map):

• to control the exhaust gas recycling electrovalve with an OCR voltage,

• to determine the exhaust gas recycling rate,

• to correct the OCR applied to the exhaust gas recycling electrovalve so as to

obtain the theoretical recycling rate equal to the measured rate.

Note: Exhaust gas recycling rate = difference between the measurement from the

air flowmeter and the calculation of the amount of air entering the engine

(depending on engine speed and air temperature).

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