1999 AUDI A4 engine

24-117

- 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-, -7- and -0- to input display group number 70 (070),
and press -Q- button to confirm input.
Read Measuring Value Block 70 1 2 3 4

Indicated on display (1-4 = display fields)
Note:
During this diagnosis there should not be any load placed on the engine,
otherwise the diagnosis is interrupted and must be started again. - Press button -4- to select "Basic Setting" function 04 (diagnosis for
EVAP canister purge regulator valve is initiated).
System in Basic Setting 70 1 2 3 4

Indicated on display (1-4 display fields)
If the diagnosis is initiated by the ECM, the display changes from "Test
OFF" to "Test ON" in display field 4.
Note:
If the display changes from "Test ON" to "Test OFF" during the test,
accelerate with a brief burst to repeat the test. - Continue to run engine at idle until "EVAP OK" is indicated in display
field 4.
Pa
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24-121

Checking EVAP canister purge regulator
valve voltage supply

Test conditions

Fuse for EVAP canister purge regulator
valve OK

- Disconnect harness connector from EVAP
canister purge regulator valve.

If LED test light does not light:
If wiring is OK: - Connect VAG1527B LED voltage tester between connector terminal 1
(B+) and engine Ground.
- Operate starter motor.
Specified value: LED must light up
- Check wiring for open circuit between connector terminal 1 and fuse,
according to wiring diagram; repair if necessary.

Specified value: 1.0 max.- Check fuel pump relay page 24
-95
.
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24-125

Voltage supply, checking

If LED tester does not light: - Disconnect harness connector for LDP -V144-.
- Connect VAG1527B LED voltage tester between connector terminal 3
(B+) and engine Ground.
- Start engine and run engine at idle.
LED must light up.
- Check fuse for LDP -V144-.
- Check wiring for open circuit between terminal 3 and fuse, according to
wiring diagram.

Specified value: max. 0.5 .- Check fuel pump relay and signal to relay page 24
-95
.
Pa
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24-126

Intake air system, checking for leaks


Required special tools and test equipment

VAG1551 or VAG1552 Scan Tool (ST) with
VAG1551/3 adapter cable
Engine leak detector spray G 001 800 A1

Notes:
If there are leaks, intake manifold vacuum will
draw in the leak detector spray with outside air.
The spray reduces the ability of the fuel/air
mixture to ignite, which causes a drop in engine
speed and a significant increase in CO-content.
Observe the safety precautions listed on the
container.

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
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24-127

Read Measuring Value Block 1 1 2 3 4

Indicated on display (1-4 = display fields)
- Monitor oxygen sensor control in display fields 3 and 4.

Display fields

1 2 3 4
Display group 1: Engine idle speed
Display xxxx RPM
xx.x C
xx.x% xx.x %
Indicates Idle speed
(in 40 RPM
steps) Engine Coolant Temperature
(ECT) Oxygen Sensor (O2S)
control, Bank 1 Oxygen Sensor (O2S)
control, Bank 2
Range 0 - 6800 RPM
-48.0 - 143.2 C
(-54 - 289 F)
-25.0 to +25.0 % -25.0 to +25.0 %
Specified
value 620 - 740
RPM
(all-wheel
drive) --- -10.0 to +10.0 %
value must change by at
least 2 % -10.0 to +10.0 %
value must change by at
least 2 %
740 - 860
RPM
(front-wheel
drive)
- Systematically spray parts of intake air system with engine leak detector spray.
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If engine speed drops, or the values displayed for oxygen sensor control change:
- Check for leaks in area of intake air system most recently sprayed, and eliminate leaks.
Pa
ge 166 of 166 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.24.1