Secondary Air Injection - Operation, R And R Information
Group: 26Number: 9-O2
Date: Sept. 15, 1994
Subject:
Secondary Air Injection (AIR) System
Model(s):
Passat GLX with engine code AAA from 1993 m.y.
Corrado SLC with engine code AAA from 1993 m.y.
These pages will be added to the Repair Manual Microfiche, Repair Group 26 at the next filming.
Secondary Air Injection (AIR) System
Function
The Secondary Air Injection (AIR) System injects air behind the exhaust valves for 65 seconds during a cold start when the engine coolant temperature is between 15°C and 35°C (58°F and 95°F). The additional air provided by the pump to the exhaust initiates after-burning. This after-burning shortens the heat up phase of the Catalytic Converter resulting in reduced emissions.
The system is activated by the Motronic Engine Control Module (J220) via the AIR Relay (J316) to the Change-Over Valve (N180) and the AIR Inlet Valve.
In addition, each time the engine is started again after the initial start and remains at idle, the AIR system is switched on after a 20 second delay for 5 seconds. At the same time, the AIR system is checked via the On Board Diagnostic (OBD) system.
Note
^ Components marked with (*) and the AIR Relay (J316) are checked via the OBD system.
Secondary Air injection System:
1 - Secondary Air injection (AIR) Pump Motor (V101)*
2 - Engine lifting bracket
3 - Pump bracket
^ With attachment for Change-Over Valve
4 - 25 Nm (18 ft lb)
5 - Connector
6 - 10 Nm (7 ft lb)
7 - Change-Over Valve (N180)*
8 - Vacuum hose
^ To intake manifold
9 - Vacuum hose
^ From Change-Over Valve to Secondary Air Injection Valve
10 - Air intake duct from air cleaner
11 - Air duct to Secondary Air Injection Inlet Valve
12 - To air cleaner
13 - Secondary Air injection Inlet Valve
14 - 15 Nm (11 ft lb)
15 - O-ring
^ Replace if damaged
16 - Air passage in cylinder head
Secondary Air Injection (AIR) system components, removing/installing
Caution
Before disconnecting battery:
^ Obtain radio security code.
^ Wait at least 20 seconds after switching ignition off to allow the hot wire in the Mass Air Flow sensor to burn clean.
^ To prevent damage to the ECM, disconnect the battery only with the ignition turned off.
- Remove the front bumper.
- Disconnect hose clamps from radiator hose connections. Do not kink or bend hoses and lines. Do not open A/C system.
- Remove left and right radiator securing bolts.
- Remove bolts from front hood lock carrier. Pull carrier with attachments slightly forward and support.
- Remove air intake duct connecting air cleaner to AIR Pump Motor.
- Remove air duct from AIR Pump to AIR Inlet Valve.
- Pull off vacuum hose from AIR Inlet Valve.
- Remove oil dipstick guide tube bolt from intake manifold.
- Remove bolts for AIR Inlet Valve, from bottom of intake manifold and pull valve out.
- Remove connectors from AIR Inlet Valve and AIR Pump.
- Remove Change-Over Valve from pump bracket.
- Remove Change-Over Valve from engine lifting eye.
- Carefully pull AIR Pump out between unbolted lock carrier and bottom of intake manifold.
- Installation is in reverse order of removal.
Secondary Air Injection (AIR) Inlet Valve, checking
- Loosen the hose clamp on hose to AIR Inlet Valve and pull off hose.
Testing Secondary Air Injection Inlet Valve:
- Connect vacuum pump US 8026 to vacuum hose (arrow 1) of AIR Inlet Valve.
Caution
Do not use compressed air for the following test
- Push auxiliary hose (arrow 2) onto hose connector and blow into it by mouth. AIR Inlet Valve should be closed.
- Operate vacuum pump US 8026. AIR Inlet Valve should open.
Secondary Air Injection (AIR) Pump Motor (V101), checking
Test condition:
Secondary Air Injection Relay And Fuse:
Fuse for AIR Relay (J316) (arrow) OK
- Remove hose clamp for hose to AIR Inlet Valve, pull hose off and point opening upward.
- Start engine and let idle.
^ After approximately 20 seconds, the AIR Pump Motor will switch on for 5 seconds and secondary air should blow from hose.
If AIR Pump does not start:
- Switch engine off.
- Remove connector from AIR Pump Motor.
- Connect LED tester VAG 1 527B to harness connector.
- Start engine and let idle.
^ After approximately 20 seconds the LED tester must light up.
If LED lights up:
- Replace AIR Pump Motor (V101).
If LED does not light up:
- Troubleshoot open circuit using applicable wiring diagram, and repair as necessary.
- Read Diagnostic Trouble Code (DTC) using Scan Tool VAG 1551. If this test has caused a DTC to be stored in memory, erase DTC memory.
Change-Over Valve, checking
- Remove hose clamp for hose to AIR Inlet Valve, pull hose off and point
opening upward.
- Start engine and let idle.
^ After approximately 20 seconds ,the AIR Pump Motor will switch on for 5 seconds and it should be possible to feel suction (from the intake manifold) at the end of the hose.
If you cannot feel suction;
- Switch engine off.
- Remove harness connector from Change-Over Valve and connect LED tester 1527B.
- Start engine and let idle.
^ After approximately 20 seconds, LED tester should light up for about 5
seconds.
If LED test lamp lights up:
- Replace shut off valve.
If LED does not light up:
- Troubleshoot circuit using applicable wiring diagram, and repair as necessary.
- Read Diagnostic Trouble Code (DTC) using Scan Tool VAG 1551. If this test has caused a DTC to be stored in memory, erase DTC memory.