lock AUDI A8 1998 D2 / 1.G AEB Engine Turbocharger Boost Control And Checking

24-123


Turbocharger boost controls,
checking

Boost pressure regulation, checking


- Connect VAG 1551 or VAG 1552 scan tool and
press buttons -0- and -1- to insert "Engine
Electronics" address word 01 (with engine
running at idle) Page 01
-7 .
Rapid data transfer
HELP
Select function XX

Indicated on display
- Press buttons -0- and -8- to select "Read Measuring Value Block"
function 08, and press -Q- button to confirm input.
Read Measurin
g Value Block
HELP
Input displa
y group number XXX

Indicated on display
- Press buttons -1-, -1- and -4- to input display group number 114, and
press -Q- button to confirm input.
Read Measuring Value Block 114 1 2 3 4

Indicated on display (1-4 = display fields)
WARNING!
A second technician is required to operate the VAG 1551 scan tool
during the road test. - Road test car at wide open throttle at 4000 RPM.
Pa
ge 1 of 17 Turbochar
ger boost controls, checkin
g
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.3

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If the actual engine load is not within the
tolerance, possible malfunctions are:

Wastegate bypass regulator valve electrical
malfunction
Hoses for wastegate bypass regulator valve
disconnected or blocked
Wastegate bypass regulator valve -N75-
blocked
Air leaks between turbocharger and intake
manifold
Wastegate bypass regulator valve mechanical
controls sticking (linkage, shaft)
Turbocharger faulty (turbine blocked by foreign
object)
Pa
ge 4 of 17 Turbochar
ger boost controls, checkin
g
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.3

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- Press buttons -0- and -8- to select "Read
Measuring Value Block" function 08, and press -
Q- button to confirm input. Read Measurin
g Value Block
HELP
Input displa
y group number XXX

Indicated on display
- Press buttons -1-, -1- and -3- to input display group number 113, and press -Q-
button to confirm input.
Read Measuring Value Block 113 1 2 3 4

Indicated on display (1-4 = display fields)
- Compare displayed value with specified air pressure value (display field 4):

Display fields

1 2 3 4
Display group 113: Boost pressure regulation
Display xxx RPM xx.xx ms
xxx
xxxx mbar
1)

Indicates Engine speed
(in 40 RPM steps) Engine load Throttle valve angle Air pressure
Range 0-6800 RPM 0.00-8.50 ms
0-90
559-1118 mbar
Specified value 0 RPM 0.00 ms
0-5 0 m
400 m
1000 m
1013 mbar
970 mbar
900 mbar
Pa
ge 12 of 17 Turbochar
ger boost controls, checkin
g
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.3