1997 AUDI A4 wiring

26-48

Test requirements:

Vehicle diagnostic, testing and information
system VAS 5051 or VAG 1551 Scan Tool
connected.

Test sequence

Note:
The secondary air injection solenoid valve -
N112- and the wiring connections are monitored
by the engine control module.

- Read out Diagnotic Trouble Code (DTC)
memory of engine control module.
If a DTC relating to the secondary air injection
solenoid valve -N112- is displayed:

Note:
The illustration shows bottom view of intake line. - Remove hoses from secondary air injection solenoid valve -N112- (-2-)
but leave electrical connector plugged in.
Location: below intake line
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Checking power supply

Note:
The power supply for the secondary air injection
solenoid valve -N112- is via the fuel pump relay.

Test requirements:

Fuse for secondary air injection solenoid
valve OK.

Electrical Wiring Diagrams, Troubleshooting &
Component Locations binder

Fuel pump relay OK.

Repair Manual, 1.8 Liter 4
-Cyl. 5V Turbo Fuel
Injection & Ignition, Engine Code(s): AWM, Repair Group 24


- Disconnect connector from valve.

- Connect voltage tester VAG 1527 B as follows:Connector
Measure to
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If the LED does not light up:

- Check wiring from contact 1 on the connector
via the fuse to the fuel pump relay for an open
circuit:

Electrical Wiring Diagrams, Troubleshooting &
Component Locations binder
- Repair open circuit, if necessary
If the LED lights up:

- Check actuation.

Checking actuation

- Connect voltage tester VAG 1527 B to contacts 1 (positive) and 2 of
connector.
- Initiate output Diagnostic Test Mode (DTM) and activate secondary air
injection solenoid valve -N112-.

LED must flash.
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26-53
If the LED lamp does not flash or if it lights up
continuously:

- Connect VAG 1598/31 test box to wiring
harness leading to engine control module;
engine control module should not be connected:

Repair Manual, 1.8 Liter 4
-Cyl. 5V Turbo Fuel
Injection & Ignition, Engine Code(s): AWM, Repair Group 24


If the wiring is OK: - Check for open circuit and short to positive or Ground in following
wiring connection: Connector
contact
Test box VAG 1598/31
2 9
- Repair any open/short circuit as necessary.
- Replace engine control module.
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26-57

- Check for open circuit in wiring from battery +
(terminal 30) to fuse S130 for secondary air
injection pump relay (in 3-position in E-box of
plenum chamber, position 2).

Electrical Wiring Diagrams, Troubleshooting &
Component Locations binder

If specified value is not attained: - Connect multimeter as follows to measure voltage.3-position relay carrier in E-box in plenum chamber,
position 2
contact
Measure to

4 Engine
Groung
- Operate starter briefly.
Specified value: approx. battery voltage
- Carry out following tests:

Electrical Wiring Diagrams, Troubleshooting & Component Locations
binder - Check fuse S234 (in fuse box, position 34).
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26-58

- Check for open circuit in wiring from
secondary air injection pump relay (in 3-
position relay carrier in E-box of plenum
chamber) via fuse S234 (in fuse box, position
34) to fuel pump relay.

Electrical Wiring Diagrams, Troubleshooting &
Component Locations binder
Check actuation of secondary air pump relay

- Switch ignition off.

- Remove secondary air injection pump relay.

- Connect voltage tester VAG 1527 B as follows:3-position relay carrier in E-box in plenum chamber,
position 2
contact
Measure to

6 Engine
Ground
- Initiate output Diagnostic Test Mode (DTM) and activate secondary air
injection pump relay.

LED must flash.
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If LED does not flash:

- Switch ignition off.

- Connect VAG 1598/31 test box to wiring
harness leading to engine control module;
engine control module should not be connected:

Repair Manual, 1.8 Liter 4
-Cyl. 5V Turbo Fuel
Injection & Ignition, Engine Code(s): AWM, Repair Group 24


If no malfunction is found: - Check for open circuit and short to positive or Ground in following
wiring connection: 3-position relay carrier in E-box in plenum
chamber, position 2
Contact
Test box VAG
1598/31


6 66
- Repair any open/short circuit as necessary.
- Replace Secondary Air Injection Pump relay -J299-.
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If LED does not flash:
Electrical Wiring Diagrams, Troubleshooting & Component Locations
binder
Electrical Wiring Diagrams, Troubleshooting & Component Locations
binder
If no malfunction is found: - Connect voltage tester VAG 1527 B between contacts 1 and 2.
- Initiate output Diagnostic Test Mode (DTM) and activate Secondary Air
Injection (AIR) Pump relay -J299-.

LED must flash.
- Carry out following tests:
- Check wiring connection from contact 1 of connector to secondary air
injection pump relay (in 3-pin relay carrier in electronic box (plenum
chamber), for open circuit.
- Check wiring connection of contact 2 of connector to Ground for
open circuit: - Replace Secondary Air Injection (AIR) Pump motor -V101-.
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