1999 AUDI A4 group 24

Repair Group 24
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Checking LDP via Read Measuring Value
Block (vehicles with mechanical throttle
control)

Note:

Always replace O-rings, sealing rings and
gaskets.
Radiator fan must not come on during the
test!

Troubleshooting requirements
DTC memory checked and no DTCs stored
All electrical consumers switched OFF
A/C switched OFF
Intake Air Temperature lower than 90 C
Display group 004, channel 4.

Engine Coolant Temperature less than 95
C Display group 004, channel 3.

Throttle angle less than 10 % Display
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group 003, channel 3.
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- Press 0 and 1 buttons to select Address word
01: "Engine electronics".

- Press Q button to enter input.

-
Press button.Rapid data transfer
HELP
Select Function XX

Display will appear as shown
- Press 0 and 8 buttons to select Function 08: "Read measuring value
block"
- Press Q button to enter input.
Read measurin
g value block
Enter displa
y group number XXX

Display will appear as shown
- Press 0, 7 and 1 buttons to select "display group 71".
- Press Q button to enter input.
Read measuring value block Reed closed
break
Test OFF

Display will appear as shown
Note:
Condition for continuing test is "Reed closed" on the display.The display does not always show "Abort".If the display: "reed open" appears: Briefly open the filler cap to
reduce pressure - this will close the reed contact. Continue checking
as follows:
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If LED does not light up:

Electrical Wiring Diagrams, Troubleshooting & Component Locations
If wiring is OK:
Repair Manual, Fuel Injection & Ignition, Repair Group 24 - Check electrical wiring from terminal 3 via fuse for fuel pump relay for
open circuit. - Repair wiring as necessary.
- Check fuel pump relay:
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If you did not find any malfunction, however the
Leak Detection Pump (LDP) did not function
during the output Diagnostic Test Mode (DTM):

- Replace Leak Detection Pump (LDP) -V144
Page 20
-162
.
If the LED does not blink, although wiring is OK:

- Replace 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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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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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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