1996 AUDI A4 APB Engine Charge Air System With Turbocharger Workshop Manual

remains connected.

- Attach assisting hose to one connection of
valve.
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21-21

- Initiate output Diagnostic Test Mode (DTM) and
activate recirculating valve for turbocharger -
N249-.

Repair Manual, 2.7 Liter V6 5V BiTurbo Fuel
Injection & Ignition, Engine Code(s): APB, Repair Group 01

Output diagnostic test mode Recr. valve for turbocharger -N249

Indicated on display
If valve does not click:
If valve does not open and close properly: Valve must click...
...and must open and close (can be tested by blowing into assisting
hose).
- Check internal resistance of valve.
- Replace recirculating valve for turbocharger -N249-.
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21-22

Checking internal resistance

- Disconnect connector at valve.

If specified value is not obtained:
If the specified value is met: - Connect multimeter at valve for resistance measurement.

Specified value: 27 ... 30
- Replace recirculating valve for turbocharger -N249-.
- Check voltage supply
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21-23

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 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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21-24
If LED does not light:

- Check wire connection from terminal 1 to Fuel
Pump (FP) relay via fuse for 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, 2.7 Liter V6 5V BiTurbo Fuel
Injection & Ignition, Engine Code(s): APB, Repair Group 24

If LED lights:

- Check activation, Page 21
-25
.
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21-25

Checking activation

Repair Manual, 2.7 Liter V6 5V BiTurbo Fuel Injection & Ignition,
Engine Code(s): APB, Repair Group 01

If LED does not blink or if it remains constantly lit:
Repair Manual, 2.7 Liter V6 5V BiTurbo Fuel Injection & Ignition,
Engine Code(s): APB, Repair Group 24
- Connect VAG 1527B voltage tester to connector terminals 1 (B+) and
2.
- Initiate output Diagnostic Test Mode (DTM) and activate recirculating
valve for turbocharger -N249-.

LED must blink.
- Connect VAG 1598/31 test box at wiring harness to ECM. Do not
connect ECM.

- Check the following wire connections for open circuit and short circuit
to Ground (GND) and B+: Harness connector terminal
VAG 1598/31 test box
Bushing
2 9
- Repair open circuit or short circuit if necessary.
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21-26
If wire connection is OK:

- Replace Engine Control Module (ECM).

Repair Manual, 2.7 Liter V6 5V BiTurbo Fuel
Injection & Ignition, Engine Code(s): APB, Repair Group 24

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21-27


Charge air pressure sensor -G31-,
checking

Special tools and equipment

VAG 1526A
VAG 1594A
VAG 598/31
VAS 5051 with VAG 5051/1
- or
VAG 1551 with VAG 1551/3A
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pair&id=AUDI.B5.GE05.21.1