AUDI A4 1997 B5 / 1.G EVAP Service Manual

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Evaporative Emissions (EVAP) System,
Diagnosis using KLI9210 EVAP Tester


Description
The leak detection threshold has recently
changed from 1.0 mm (0.040 in.) to 0.5 mm
(0.020 in.). These changes to EPA regulations
regarding EVAP system integrity indicated that
additional resources for more accurate EVAP
system diagnosis are necessary.
The KLI9210 EVAP Tester allows testing using
nitrogen to pressurize the EVAP system and a
smoke generator or ultrasonic tester to locate the
source of EVAP system concerns.
The following procedure will outline general use
of the KLI9210 EVAP Tester. It is intended as a
guideline, as EVAP systems vary between
models.

Test EVAP system using Leak Detection
Pump (LDP) -V144- (m.y. 1998 and later)
For vehicles without LDP, proceed to "Perform
EVAP tester self-test".
For vehicles with LDP:

- Perform leak test using VAS 5051 Scan Tool
and Basic Setting mode, Page 20
-139
.
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If vehicle fails above test ("System not OK"):

- Verify fuel cap is properly closed; repeat test.
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If "System OK" after re-test:

- Erase DTC memory (if necessary).

- Repeat test several times to ensure proper
EVAP system operation (remove and re-install
fuel cap before each test).

- Perform quality check and return vehicle to
customer.

Note:
If the vehicle passes the above EVAP system
test, DTCs may be sporadic; the entire EVAP
system should be carefully inspected.
If VAS 5051 continues to indicate "System not
OK" after re-test, proceed to next step.

Perform EVAP tester self-test

Note:

Always perform system self-test of KLI9210
EVAP Tester prior to use to ensure that there
are no leaks.
Refer to KLI9210 instruction manual for specific
instructions.
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If gauge does not read 14 1 in. of water: - Connect vehicle interface hose to self-test port -1-, ensuring that fitting
is finger-tight. Over-tightening will damage fitting.
- Turn control valve -2- to "Test".

Gauge -3- should read 14 1 in. of water.
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- Verify that valve on EVAP tester nitrogen
cylinder is open and that cylinder has sufficient
pressure before continuing.

Note:
If gauge still does not read within above range, contact K-Line Customer
Service - Technical Support for additional instructions before continuing.
If gauge leaks down:
If gauge continues to leak down: - Turn fine adjust regulator knob (arrow) until gauge reads 14 in. of
water; tighten lock nut.
- Check flow meter -4-. (upper illustration).
Meter must indicate no flow.
- Turn control valve to "Hold" position.
- Check gauge.
Gauge must hold pressure
- Verify that vehicle interface hose is firmly seated and repeat previous
six steps before continuing.
- Use ultrasonic tester (described later) to locate and repair leak before
continuing.
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Note:
If the leak cannot be located or repaired, contact
K-Line Customer Service - Technical Support.

Calibrate KLI9210 Tester
Determine vehicle leak threshold:

To m.y. 2000: leak threshold 0.040 in.

From m.y. 2001: leak threshold 0.020 in.

Test fuel cap - Attach test hose to appropriate preset port (black arrows).
- Turn control valve from "Hold" to "Test".
- Set flow meter flag (white arrow) at indicated value on flow meter.
- Turn control valve to "Hold"; remove test hose.
- Connect fuel cap tester to hose.

If no flow is indicated: - Screw fuel cap tightly to cap receiver (arrow).
- Turn control valve to "Test".
- Read flow meter on tester.
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- Proceed to "Test LDP for internal leaks".
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If flow is indicated:

- Replace fuel cap and re-test.
If new fuel cap shows no flow:

- Repeat Leak Test, with new fuel cap installed,
using VAS 5051 and Basic Settings mode,
Page 20
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.
If Leak Test shows 'System OK":

- Perform quality check and return vehicle to
customer.

Test LDP -V144- for internal leaks
If vehicle is not LDP-equipped, proceed to "Test
EVAP system".

- Clamp off LDP outlet (EVAP side) using Special
Tool No. 3094 or equivalent.

CAUTION!

Clamp only soft rubber lines when isolating a
leak. To avoid risk of damage, never clamp
hard plastic lines!

-
Repeat Leak Test using VAS 5051 and Basic
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Setting mode.

VAS 5051 should immediately indicate "System
OK"

- Repeat test several times to verify result.

If test continues to indicate "System OK",
remove clamp and proceed to "Test EVAP
System".
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If VAS 5051 indicates "System not OK":

- Replace LDP and repeat test.

If VAS 5051 indicates "System OK" after LDP is
replaced and test result is verified:

- Perform quality check and return vehicle to
customer.

Test EVAP System
Also Page 20
-134
.
If vehicle is not LDP-equipped:

- Plug or clamp EVAP canister outlet and proceed
to step "Continued for all vehicles" (below).
If vehicle is LDP-equipped:

- Plug or clamp LDP inlet (filter side) using
Special Tool No. 3094 or equivalent.
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