AUDI A4 1999 B5 / 1.G APB Engine Secondary Air System User Guide

26-41

Checking voltage supply

- Disconnect connector from Secondary Air
Injection (AIR) solenoid valve -N112-.

If LED does not light: - Connect VAG 1527B voltage tester as follows:Harness connector terminal
Measure to
1 Engine Ground (GND)
- Operate starter briefly.

LED must light.
- Perform following tests marked with dots:

Check fuse -S234- (in fuse holder, position 34).
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Electrical Wiring Diagrams, Troubleshooting & Component Locations
Repair Manual, 2.7 Liter V6 5V BiTurbo Fuel Injection & Ignition,
Engine Code(s): APB, Repair Group 24

Checking activation
Check wire connection from terminal 1 of connector via fuse -S234-
(in fuse holder, socket 34) to Fuel Pump (FP) relay for open circuit: Check Fuel Pump (FP) relay.

- Connect VAG 1527B voltage tester between terminal 1 and 2.
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- Initiate output Diagnostic Test Mode (DTM) and
activate Secondary Air Injection (AIR) solenoid
valve -N112

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

Output Diagnostic Test Mode Secondary. air. inj. solenoid valve -N112

Indicated on display
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

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 44
- Repair open circuit or short circuit if necessary.
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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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Secondary Air Injection (AIR) pump relay -
J299- and activation, checking

Special tools and equipment

VAG 1526A
VAG 1527B
VAG 1594A
VAG 1598/31
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26-46
Installation location Installation locations-
Overview.
Repair Manual, 2.7 Liter V6 5V BiTurbo Fuel
Injection & Ignition, Engine Code(s): APB, Repair Group 24


Test sequence

- Initiate output Diagnostic Test Mode (DTM) and
activate Secondary Air Injection (AIR) pump
relay -J299-

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


A - If relay does not trigger:
The Secondary Air Injection (AIR) pump relay (in 3-socket relay
carrier in the E-box, at left in plenum chamber, position 2) must
engage and the Secondary Air Injection (AIR) pump motor -V101-
must run in intervals
- Check voltage supply of Secondary Air Injection (AIR) pump relay
Page 26
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.
-
Check activation of Secondary Air Injection (AIR) pump relay Page
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B - If relay triggers, but Secondary Air Injection (AIR) pump does not run: 26
-49
.
- Check voltage supply of Secondary Air Injection (AIR) pump motor
Page 26
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26-47

Checking voltage supply of Secondary Air
Injection (AIR) pump relay

- Switch ignition off.

- Remove Secondary Air Injection (AIR) pump
relay

- Connect multimeter for voltage measurement as
follows.

3-socket relay carrier in E-box,
plenum chamber, position 2
terminal
Measure to

8 Engine
Ground
(GND)


Specification: approx. battery voltage
If specified value is not obtained:

- Perform following tests marked with dots:

Check fuse -S130- (40 A) in 3-socket relay carrier in E-Box, plenum
chamber, position 7.
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Electrical Wiring Diagrams, Troubleshooting & Component Locations Check wire connection from battery + (terminal 30) to Secondary Air
Injection (AIR) pump relay -J299- (in 3-socket relay carrier in E-Box,
plenum chamber, position 2) for open circuit.
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- Connect multimeter for voltage measurement as
follows:

3-socket relay carrier in E-box,
plenum chamber, position 2
terminal
Measure to

4 Engine
Ground
(GND)

- Operate starter briefly.


Specification: approx. battery voltage
If specified value is not obtained:

- Perform following tests marked with dots:

Electrical Wiring Diagrams, Troubleshooting & Component Locations Check fuse -S234- (in fuse holder, position 34). Check wire connection from Secondary Air Injection (AIR) pump relay
-J299- (in 3-socket relay carrier in E-box, plenum chamber) via fuse -
S234- (in fuse holder, position 34) to Fuel Pump (FP) relay for open
circuit:
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