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Display group 030 (EVAP system diagnosis)
Notes:
Display group 030 is only considered on vehicles with sensor for EVAP canister -G172-.
If the value of the EVAP throughput diagnosis is not set to "0" in display group 029, display field 1 during regeneration of
the readiness code, and/or there is a malfunction in DTC memory that relates to the EVAP system, display group 030 is
used to carry out a selective diagnosis.
Since the EVAP system is automatically shut off during "Basic Setting" function 04, display group 030 can only be
evaluated using "Read Measuring Value Block" function 08.
When diagnostic conditions are fulfilled, the Engine Control Module (ECM) checks the EVAP system at each start with the
help of the sensor for EVAP canister -G172-. The pressure between the EVAP canister and EVAP canister purge
regulator valve is measured with the sensor for EVAP canister -G172-.
The diagnostic conditions are only fulfilled during a drive of approx. 1-1/2 to 5 minutes at 80-100 km/h (50-63 mph) with
manual transmission in 4th or 5th gear, or automatic transmission selector lever in "D" position, preferably in 4th gear. If
the diagnostic conditions are fulfilled, the diagnosis is active. To get the diagnosis results, you have to drive approx. 1-1/2
to 5 minutes under the diagnostic conditions, while the pressure has to be measured with closed EVAP canister purge
regulator valve. First, the pressure must be measured with the valve closed. You can get the valve to close most easily by
having a preceding deceleration fuel shut-off. If there are problems in shutting the EVAP canister purge regulator valve by
deceleration fuel shut-off, it can also be shut by running display group 030 in "Basic Setting" function 04. Then the
pressure has to be measured again in "Read Measuring Value Block" function 08 with valve fully open.
The diagnosis is recognized as OK if the EVAP system low pressure measured in display field 1 is greater than the actual
calculated EVAP system minimum low pressure in display field 2.
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01-217
Display shows
Display/specified value
Designation/diagnosis
Basic setting 30
1 2 3 4 -- mbar 1 = Currently measured EVAP system under pressure
-- mbar 2 = Currently calculated EVAP minimum under pressure
0 - 99% 3 = Duty cycle (triggering) EVAP canister purge regulator valve
0% = completely open
99% = completely closed
X X X X X 4 = Diagnosis status and/or result Note on display field 2:
An under pressure calculated from the momentary throughput of the Mass Air Flow (MAF) sensor (intake air mass) is
displayed.
Notes on display field 4:
0 1 X X X = Diagnosis carried out, diagnosis OK
1 0 X X X = Diagnosis carried out, malfunction recognized, diagnosis is continued
The display positions marked with X do not have to be fulfilled to evaluate the diagnostic status and/or result.
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01-218
X
X
X
X
X
Meaning of 5-digit "Diagnostic Status and/or Result"
1 = Diagnostic conditions during test drive (approx. 1-1/2 to 5 minutes at 80-100 km/h (50-63 mph) with
manual transmission in 4th or 5th gear, or automatic transmission selector lever in "D" position, preferably
in 4th gear)
Manual transmission: 8 - 45%
Automatic Transmission: 8 - 20%
Value "0" = Diagnostic conditions not fulfilled
Value "1" = Diagnostic conditions fulfilled
Engine speed: 1600 RPM - 4500 RPM ( display group 003) Intake air through Mass Air Flow (MAF) sensor: 22 g/sec - 56 g/sec ( display group 019) Throttle angle: ( display group 003)
2 = Pressure measurement w/EVAP canister purge regulator valve completely closed
Value "0" = Pressure measurement not completed yet
Value "1" = Pressure measurement completed
3 = Pressure measurement w/EVAP canister purge regulator valve completely open
Value "0" = Pressure measurement not completed yet
Value "1" = Pressure measurement completed
4 = Diagnostic status
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) - Multi
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(MFI
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11/22/2002 htt
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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1
