AUDI A4 1999 B5 / 1.G EVAP Owner's Guide

20-156

Checking output wiring (vehicles with
electronic throttle control)

- Connect voltage tester VAG1527B as follows:Electrical connector terminal
Specification
2 Battery Positive
- Initiate Diagnostic Test Mode (DTM) Page 20
-146
.
-
Press button until following display is shown:
Output Diagnostic Test Mode LDP leak test

Indicated on display:
If LED does not blink:
LED must blink
- Switch ignition off.
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20-157


- Remove weatherstrip at plenum chamber -arrows-.
- Remove cover for plenum chamber -1- toward front.
- Remove cover for E-box in plenum chamber.

Note:
Disconnect or connect the Engine Control Module (ECM) connector only
with ignition switched off. - Carefully lever off clamp -arrow- with screwdriver.
- Unlatch clip and disconnect connector for Engine Control Module
(ECM).
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20-158


- Connect test box VAG1598/22 to harness connector. The ground
clamp (not visible in the illustration) must be connected to battery
ground connection. Do not connect ECM.

- Check the following wire connection for open circuit or short circuit to
Ground or plus (B+): Electrical connector terminal
Test box VAG1598/22 socket
2 25
- Repair wiring or short circuit if necessary.
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20-159
If you did not find any malfunction, however the
Leak Detection Pump (LDP) did not function
during the Output Diagnostic Test Mode (DTM):

- Replace LDP Page 20
-162
If the LED does not blink, although wiring is OK:

- Replace the Engine Control Module (ECM)

Repair Manual, Fuel Injection & Ignition,
Repair Group 24
- Generate readiness code:

Repair Manual, Fuel Injection & Ignition,
Repair Group 24
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20-160

Checking input wiring (vehicles with
mechanical throttle activator)

- Switch ignition off.

- Connect test box VAG1598/22 to harness connector Page 20
-153
,
"Checking output wiring."

Repair Manual, Fuel Injection & Ignition, Repair Group 24 - Check the following wire connections for open circuit or short circuit to
Ground or plus (B+): Electrical connector terminal
Test box VAG1598/22 socket
2 37
- Repair open or short circuit as necessary.
- Generate readiness code:
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20-161

Checking input wiring (vehicles with
electronic throttle control)

- Switch ignition off.

- Connect test box VAG1598/31 to harness connector Page 20
-156
,
"Check output wiring."

Repair Manual, Fuel Injection & Ignition, Repair Group 24 - Check the following wire connections for open circuit or short circuit to
Ground or plus (B+): Electrical connector terminal
Test box VAG1598/31 socket
1 80
- Repair open or short circuit as necessary.
- Generate readiness code:
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20-162

Leak Detection Pump (LDP) -V144,
removing and installing

Checking LDP Page 20
-139


Removing

- Remove left rear wheel.

- Remove left rear wheel housing liner.

Repair Manual, Body Exterior, Repair Group
66


- Cut tie wrap -1- and remove hose -2- .
- Disconnect hose coupling -3- after pressing tab.
- Remove nuts -arrows-.
- Switch off ignition.
- Remove LDP, unclip and disconnect connector.
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20-163

Installing
Installation is in reverse order of removal, but do
the following:

Note:
Secure all hoses with clamps that are the same
as factory installed.

CAUTION!

Always refer to the latest parts catalog to
ensure that you use original equipment fuel
hose clamps.

Tightening torque: - Secure hose -2- with tie wrap -1- to bracket of LDP.Component
Nm
Bracket for Leak Detection Pump (LDP) 7.5
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20-164

EVAP canister, removing and installing


Note:
To check seal integrity, perform tank leak
diagnosis Page 20
-139
.

Removing

- Remove cover for EVAP canister at bottom of
spare tire well.

Installing
Installation is performed in the reverse order of the removal procedure,
during installation note the following:
CAUTION!
Always refer to the latest parts catalog to ensure that you use
original equipment fuel hose clamps. - Loosen hose connections -1- and - 3- on bleed lines.
- Remove sealing pieces out and over the bleed lines.
- Loosen studs -arrows-.
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20-165

Tightening torques

Component
Nm
EVAP canister to body 15
Cover on spare wheel well 10
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