air condition AUDI A8 1999 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.
Pa
ge 4 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

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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

24-143

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 VAG 1527B LED voltage tester between connector terminal 1
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.
- Check fuel pump relay Page 24
-81
.
Pa
ge 11 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