light AUDI A8 2000 D2 / 1.G AEB Engine Turbocharger Boost Control And Checking

24-129

Check voltage supply for wastegate bypass
regulator valve -N75-

Note:
Voltage supply for the wastegate bypass
regulator valve is provided by the fuel pump
relay.

Fuse for -N75- OK

- Disconnect harness connector from valve.

If LED does not light:
If wiring is OK: - Connect VAG 1527B LED test light between harness connector
terminal 1 and engine Ground.
- Operate starter motor.
LED test light must light up
- Check wiring for open circuit between terminal 1 to and fuse, according
to wiring diagram. Repair if necessary.
- Check fuel pump relay Page 24
-81
.
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ger boost controls, checkin
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11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
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24-130

Signal for wastegate bypass regulator valve,
checking

- Disconnect harness connector for valve -N75 .

If LED test light does not blink, or stays on continuously: - Connect VAG 1527B LED voltage tester between connector terminals
1 (B+) and 2.
- Start output Diagnostic Test Mode (DTM) and advance through test
program to select wastegate bypass regulator valve -N75- Page 01
-
42

LED test light must blink
- Connect VAG 1598/22 test box to ECM harness connector Page 01
-
56
.

If wiring is OK: - Check wiring for open circuit or short circuit to B+ between connector
terminal 2 and ECM/test box socket 64. Repair if necessary.
- Replace Motronic ECM -J220- Page 01
-57
.
- Carry out adaptation of throttle valve control module to ECM Page
24
-119
.
- Check readiness code Page 01
-59
. If Diagnostic Trouble Code
(DTC) memory has been erased, or ECM was disconnected, generate
new readiness code Page 01
-62
.
Pa
ge 9 of 17 Turbochar
ger boost controls, checkin
g
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.3