light AUDI TT 1996 8N / 1.G AEB ATW Engines Charge Air System With Turbocharger Workshop Manual

21-51
If the specified value is attained:

- Check voltage supply

Checking voltage supply

Note:
Voltage is supplied to the recirculation valve via
the Fuel Pump (FP) relay.

Test requirement

Fuse for recirculation valve OK

- Disconnect harness connector at valve.

- Connect VAG1527B voltage tester as follows:Harness connector
terminal
Measure to
1 Engine Ground (GND)
- Operate starter briefly.

LED must light.
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21-52
If LED does not light:

- Check wire connection from terminal 1 to Fuel
Pump (FP) relay via fuse for an open circuit":

Electrical Wiring Diagrams, Troubleshooting &
Component Locations
- Repair open circuit if necessary.
If wire connection is OK:

- Check Fuel Pump (FP) relay:

Repair Manual, 1.8 Liter 4-Cyl. 5V Turbo Fuel
Injection & Ignition, Repair Group 24 If LED lights:

- Check activation:

Checking activation

- Connect VAG1527B voltage tester to connector terminals 1 (B+) and 2.
-
Initiate output Diagnostic Test Mode (DTM) and activate the
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21-56


Notes: - Turn turbocharger tester on and select measuring range -I- (absolute
pressure).
- Connect test hose to connection barb -I-.
Hoses must be properly connected and there must be no possibility of
leaks, otherwise incorrect readings may result. Make sure that the test hose is not pinched at the hood or at the side
window. By pressing memory button "M" on turbocharger tester, the last test
value is saved until either memory button "M" is pressed again or the
turbocharger tester is shut-off. A blinking comma in the display field indicates that a value has been
saved. An arrow appears in the top left corner of the display field if the
turbocharger tester battery voltage drops below the permitted
threshold. Before testing, drive vehicle rapidly for at least 3 km on a road that
does not require stopping (i.e. traffic lights or similar). A second technician is required because the indicated values must be
read out while the vehicle is being driven.
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21-63
If specified value is not obtained:

- Replace wastegate bypass regulator valve -N75-
.
If the specified value is met:

Checking voltage supply

If LED does not light:
Electrical Wiring Diagrams, Troubleshooting & Component Locations - Connect VAG1527B voltage tester as follows:Harness connector
terminal
Measure to
1 Engine Ground (GND)
- Operate starter briefly.

LED must light.
- Check wire connection from terminal 1 to Fuel Pump (FP) relay via
fuse for open circuit:
- Repair open circuit if necessary.
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p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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pair&id=AUDI.B5.GE02.21.3

21-64
If wire connection is OK:

- Check Fuel Pump (FP) relay:

Repair Manual, 1.8 Liter 4-Cyl. 5V Turbo Fuel
Injection & Ignition, Repair Group 24 If LED lights:

Checking activation

Repair Manual, 1.8 Liter 4-Cyl. 5V Turbo Fuel Injection & Ignition,
Repair Group 01
If LED does not blink or if it remains constantly lit:
Repair Manual, 1.8 Liter 4-Cyl. 5V Turbo Fuel Injection & Ignition,
Repair Group 24 - Connect VAG1527B voltage tester to harness connector terminals 1
(B+) and 2.
- Initiate output Diagnostic Test Mode (DTM) and activate the wastegate
bypass regulator valve -N75-.
LED must blink.
- Connect VAG1598/31 test box at wiring harness to ECM, do not
connect ECM:
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pair&id=AUDI.B5.GE02.21.3