engine AUDI A4 1998 B5 / 1.G APB Engine Secondary Air System Workshop Manual

26-33


2 -
Motronic Engine Control Module (ECM) -
J220-
3 -
Combination valve for secondary air
injection (AIR)
4 -
Secondary Air Injection (AIR) solenoid
valve -N112-
Installation position Fig. 1
5 -
Secondary Air Injection (AIR) pump motor
-V101-
Installation position Fig. 2
6 -
Check valve
Installation position (light/dark side): Arrow
points in direction of flow, as shown in
figure.
7 -
To Intake manifold
8 -
Combination valve for secondary air
injection (AIR)
9 -
Vacuum reservoir Installation location: Under wheel housing
liner in wheel housing
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Secondary Air Injection (AIR) solenoid
valve -N112-, removing and installing


- Remove bolts (arrows) and remove engine covers -A- and -B-.

- Remove air distributor (arrows).
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Installation location Installation locations-
Overview
Repair Manual, 2.7 Liter V6 5V BiTurbo Fuel
Injection & Ignition, Engine Code(s): APB, Repair Group 24


Test requirement:

Output Diagnostic Test Mode (DTM)
performed

Checking internal resistance

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

- Connect multimeter at valve for resistance measurement.

Specified value: 25 ... 35
- If specified value is not obtained, replace Secondary Air Injection (AIR)
solenoid valve -N112-.
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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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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
-47
.
-
Check activation of Secondary Air Injection (AIR) pump relay Page
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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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26-48

- 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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