display AUDI A8 1999 D2 / 1.G AHA Engine Multiport Fuel Injection And Ignition System Owner's Guide

24-65

Continuation
If displayed value is NOT OK (not as specified):

- Road test to condition oxygen sensor (eliminate
possible contamination) and repeat test.
If displayed value is still NOT OK:

- Replace HO2S -G108-.

- Check readiness code page 01
-70
. If
Diagnostic Trouble Code (DTC) memory has
been erased, or ECM was disconnected,
generate new readiness code page 01
-73
.
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24-66

Engine operating conditions (engine
electronics), checking


Note:
This test checks whether the Motronic Engine
Control Module (ECM) -J220- recognizes the
engine operating conditions.

Required special tools and test equipment

VAG1551 or VAG1552 scan tool with
VAG1551/3 adapter

Test requirements
Engine oil temperature at least 80 C (176
F)

Checking

- Connect VAG1551 or VAG1552 scan tool and
press buttons -0- and -1- to insert "Engine
Electronics" address word 01 (with engine
running at idle) page 01
-8 .
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.
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Read Measurin
g Value Block
HELP
Input display group number XXX

Indicated on display
- Press buttons -0-, -0- and -5- to input display group number 5 (005),
and press -Q- button to confirm input.
Read Measuring Value Block 5 1 2 3 4

Indicated on display (1-4 = display fields)
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24-67

- Check engine operating conditions (display field
4):

Display fields

1 2 3 4
Display group 5: Engine electronics-operating conditions
Display xxx RPM xx.xx ms xxx km/h Idle
Part throt
Full throt 1)
Decel
Enrich
Indicates Engine speed
(in 40 RPM steps) Engine load Vehicle speed Operational condition
Range 0 - 6800 RPM 0.00 - 12.75 ms --- ---
Specified value 620 - 740 RPM
(all-wheel drive)
or
740 - 860 RPM
(front-wheel drive) 1.00 - 2.50 ms 0 km/h Idle: "Idle"
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Throttle slightly open: "Part throt"
Throttle quickly closed: "Decel"
Quick acceleration over 3000 RPM: "Enrich" 1) Possible only while driving
If displayed values are NOT OK (not as
specified):

- Check free movement of accelerator pedal and
cable.

- Check throttle valve control module page 24
-
128
.
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24-69

Test sequence

- Connect VAG1551 or VAG1552 scan tool and
press buttons -0- and -1- to insert "Engine
Electronics" address word 01 (with engine
running at idle) page 01
-8 .
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 -0-, -0- and -2- to input display group number 2 (002),
and press -Q- button to confirm input.
Read Measuring Value Block 2 1 2 3 4

Indicated on display (1-4 = display fields)
- Compare display with specified values for engine load (display fields 2
and 4):
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24-70


Display fields

1 2 3 4
Display group 2: Load measurement
Display xxx RPM xx.xx ms xx.xx ms xx.x g/s
Indicates Engine
speed
(in 40 RPM
steps) Engine load Injection
time Mass air flow
Range 0 - 6800
RPM 0.00 - 12.75 ms 0.00 -
20.00 ms 0.0 - 140 g/s
Specified
value 620 - 740
RPM
(all-wheel
drive)
or
740 - 860
RPM
(front-wheel
drive) 1.00 - 2.50 ms 2.00 - 5.00
ms 2.8 - 5.6 g/s

2520 RPM 0.80 - 2.50 ms 1.60 - 5.00
ms 10.0 - 15.0 g/s
--- If not as specified page 24
-71
,
--- If not as specified page 24
-72
,
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Evaluation of display group 2, display
field 2 Evaluation of display group 2, display
field 4
If displayed values are OK (as specified):

-
Press button to advance program
sequence.
- Press buttons -0- and -6- to select "End Output"
function 06, and press -Q- button to confirm
input.

- Switch ignition off.
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24-71
Evaluation of display group 2, display field 2 Display group:
2


Display field:
2
Possible malfunction cause
Corrective action
less than 1.00
ms
Smaller values can only occur while driving during
deceleration
more than 2.50
ms Shift lever in drive range (auto. transmission)
Engine is affected by additional consumers- Move shift lever into P or N
- Eliminate load (A/C, power steering, generator)

Poor idle (does not run on all cylinders)- Check and spark plugs page 28
-21
(checking
ignition coils)
- Check fuel injectors page 24
-102


Throttle valve control module -J338- faulty- Check throttle valve control module page 24
-
128

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24-72
Evaluation of display group 2, display field 4 Display
group: 2


Display field:
4
Possible malfunction cause
Corrective action
less than 2.8
g/s
Large amount of false air between intake air duct and
Mass Air Flow (MAF) sensor - Check intake air system for leaks (false
air) page 24
-126

larger than 5.6
g/s
Shift lever in drive range (auto. transmission)
Engine affected by additional consumers- Move shift lever into P or N
- Eliminate load (A/C, power steering,
generator)

Open circuits in wire 1 or 2 between MAF sensor and
ECM - Check voltage supply page 24
-73


Open circuit in wire 3 between MAF sensor and relay
panel - Check wiring page 24
-73
Pa
ge 94 of 166 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/23/2002 htt
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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.24.1