AUDI A6 1998 C5 / 2.G AHA Engine Multiport Fuel Injection And Ignition System Workshop Manual

24-116

Evaporative Emissions (EVAP) canister
purge regulator valve, checking


WARNING!

Whenever carrying out work on the fuel
supply and/or fuel injection systems, read
and carefully follow the Cautions, Warnings,
and rules of cleanliness page 24-9 .

Note:
Component locations page 24
-1

Required special tools and test equipment

VAG1551 or VAG1552 Scan Tool (ST) with
VAG1551/3 adapter cable

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

Function check

- 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 .
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Rapid data transfer
HELP
Select function XX

Indicated on display
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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.
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24-118


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 n.OK
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 - 93 % - 15.0 to +15.0 % 1.00 - 0.00 g/s EVAP OK If "EVAP n.OK" is indicated in display field 4:

- Check for blockage or leaks page 24
-119
.
If "EVAP OK" is indicated in display field 4:

-
Press button.Rapid data transfer
HELP

Indicated on display
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Select function XX
- Press buttons -0- and -6- to select "End Output" function 06, and
press -Q- button to confirm input.
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24-119

Checking for blockage and leaks
The EVAP canister purge regulator valve is
closed when power is off.

- Remove EVAP canister purge regulator valve -
N80- (component locations page 24
-1 )

- Connect removed valve to harness connector.

- Start output Diagnostic Test Mode (DTM) and
select -N80- page 01
-51
.

- Blow into long connection during output DTM,
and check whether valve opens and closes
properly. Replace valve if necessary.
If valve -N80- does not open and close as
specified:

- Replace -N80-.
If valve -N80- is OK:

- Check all hose connections between tank and
valve for blockage or leaks.
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24-120

EVAP canister purge regulator valve -N80-
electrical test

- Disconnect harness connector from EVAP
canister purge regulator valve.

If resistance is NOT OK: - Connect multimeter US1119 (Fluke 83 or equivalent) and check
resistance at across valve terminals.

Specified value: 22-30 - Replace EVAP canister purge regulator valve
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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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24-122

Checking signal to EVAP canister purge
regulator valve

If LED test light does not blink, or stays on:
If LED test light does not blink: - Connect VAG1527B LED voltage tester between connector terminals 1
(B+) and 2.
- Start output Diagnostic Test Mode (DTM) for EVAP canister purge
regulator valve -N80- page 01
-51
.
LED must blink
- Connect VAG1598/22 test box to ECM harness connector page 01
-
67
.

If LED test light stays on: - Check wiring between connector terminal 2 and Motronic ECM terminal
15 for open circuit or short circuit to B+.
- Check wiring between connector terminal 2 and Motronic ECM terminal
15 for short circuit to Ground.
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24-123
If wiring is OK:

- Replace Motronic ECM -J220- page 01
-68
.

- Carry out adaptation of throttle valve control
module to ECM page 24
-150
.

- 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
.
Pa
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port Fuel In
jection
(MFI
) and i
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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