display AUDI A8 1996 D2 / 1.G AEB Engine EVAP System Checking

24-139

Evaporative Emission (EVAP) Canister
Purge Regulator Valve, checking


Required special tools and test equipment

VAG 1551 or VAG 1552 Scan Tool (ST) with
VAG 1551/3 adapter cable

Test conditions
Engine coolant temperature at least 80 C
(176 F)

Function check

- 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
Selectin
g 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-, -7- and -0- to input display group number 70, and
press -Q- button to confirm input.
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porative Emissions
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Read Measuring Value Block 70 1 2 3 4

Indicated on display (1-4 = display fields)
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porative Emissions
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24-140

- Press -4- button- to select "Basic Setting"
function 04 (diagnosis for EVAP canister purge
regulator valve is initiated).

Note:
During this diagnosis there should not be any
load placed on the engine, otherwise the
diagnosis is interrupted and must be started
again. 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
ge 6 of 12 Eva
porative Emissions
(EVAP
) system, checkin
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play?action=Goto&t
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e=re
pair&id=AUDI.B5.FU02.24.4

24-141


Display fields

1 2 3 4
Display group 70: EVAP canister purge regulator valve
Display xxx % xx.x % xx.xx g/s Test OFF/Test
ON
EVAP OK
EVAP notOK
Indicated EVAP canister purge regulator
valve duty cycle during diagnosis Oxygen sensor deviation
during diagnosis Idle Air Control (IAC) valve
deviation during diagnosis Diagnosis
condition
Diagnosis
results
Range 0-100 % -25.0 to 25.0 % -2.70 to 4.16 g/s ---
Specified
value 0-100 % - 5.4 to 9.4 % 0.00-0.33 g/s EVAP OK If "EVAP notOK" is indicated in display field 4:

- Check for blockage or leaks Page 24
-142
.
If "EVAP OK" is indicated in display field 4:

-
Press button to advance program
sequence.
Pa
ge 7 of 12 Eva
porative Emissions
(EVAP
) system, 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.FU02.24.4

Rapid data transfer
HELP
Selecting function XX

Indicated on display
- Press buttons -0- and -6- to select "End Output" function 06, and
press -Q- button to confirm input.
Pa
ge 8 of 12 Eva
porative Emissions
(EVAP
) system, 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.FU02.24.4