DAF 95XF. Manual — part 168

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200438

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System inspection with DAVIE XD

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DAVIE XD diagnostics manual

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3.3 SPEED VARIATION CONTROL TEST

One of the controls of the engine management

system is the uniform operation of the engine via

the speed variation control (this speed variation is

recorded via the crankshaft sensor).

Too large a variation in speed is prevented by

correcting the quantity of injected fuel per

cylinder.

Due to a fault in the fuel system (bad injector, fuel

leakage etc.) the fuel correction applied to a

cylinder may have increased to such an extent

that it falls outside the permitted specification.

Note:

Bear in mind the fact that a mechanical defect in

a cylinder (compression loss) may affect the fuel

correction for another cylinder that falls outside

the permitted specification.

Here the relation is as follows:

In the "speed variation control" test the fuel

correction of each cylinder is determined during a

trip cycle (a trip cycle where a high engine load is

required for a long period), on the basis of the

total fuel consumption.

The "speed variation control test" in DAVIE is one

of the diagnostic tools that can be applied in case

of complaints about fuel consumption and

reduced engine power.

Other tests are the acceleration test and plotting

a boost pressure curve; in principle these have to

be carried out before the "speed variation control

test" is carried out.

in case of compression loss of cylinder:

1

5

3

6

2

4

a positive fuel correction on cylinder:

3

6

2

4

1

5

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200438

System inspection with DAVIE XD

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DAVIE XD diagnostics manual

©

200438

1

Contents

AS TRONIC

DAVIE XD diagnostics manual

3

3 AS Tronic

CONTENTS

Page

Date

1.

AS TRONIC FAULT CODES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 . . . . . 200438
1.1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 . . . . . 200438

1.2

Explanatory notes to AS Tronic fault codes. . . . . . . . . . . . . . . . . . . . . . . . 1-2 . . . . . 200438

2.

SYSTEM INSPECTION WITH DAVIE XD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . 200438
2.1

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . 200438

2.2

'Transmission' menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 . . . . . 200438

2.3

'Clutch actuator' menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 . . . . . 200438

AS TRONIC

2

©

200438

Contents

3

DAVIE XD diagnostics manual