Secondary Air Injection (AIR) Solenoid Valve -N112-, Checking

Secondary Air Injection (AIR) solenoid valve -N112-, checking
Special Tools and Equipment





- VAG1526A
- VAG1 527B
- VAG1594A
- VAG1 598/31
- VAS5051 with VAG5051/1

Test requirement:
- VAS5051 tester connected and vehicle On Board Diagnostic (OBD) function 01 "Engine electronics" selected.

Test sequence

Note: Secondary Air Injection (AIR) Solenoid Valve -N112- and wire connections are monitored by the Engine Control Module (ECM).

^ Check DTC memory of Engine Control Module (ECM).
If a malfunction regarding Secondary Air Injection (AIR) Solenoid Valve -N112- is displayed:





^ Remove rear engine cover (arrows).





- Disconnect hoses from Secondary Air Injection (AIR) Solenoid Valve -N112- (arrow); the electrical harness connector remains connected.





- Attach assisting hose to the connection of valve (indicated by an arrow).
- Initiate output Diagnostic Test Mode (DTM) and activate Secondary Air Injection (AIR) Solenoid Valve -N112-:
- Valve must click and must open and close (can be tested by blowing into assisting hose).
- If valve does not open or close properly:
- Replace Secondary Air Injection (AIR) Solenoid Valve -N112-.
- If valve does not click during output Diagnostic Test Mode (DTM):

Checking internal resistance
^ Switch ignition off.





^ Disconnect harness connector from Secondary Air Injection (AIR) Solenoid Valve -N112- (arrow).





^ Connect multimeter at valve for resistance measurement.
^ Specification: 25 to 35 rat
If specified value is not obtained:
^ Replace Secondary Air Injection (AIR) Solenoid Valve -N112-.
If specified value is obtained:

Checking voltage supply
Test requirements:
- Fuse for Secondary Air Injection (AIR) OK
Refer to Electrical Wiring Diagrams, Troubleshooting & Component Locations
^ Fuel Pump (FP) relay OK

Note: Voltage is supplied to Secondary Air Injection (AIR) Solenoid Valve -N112- via the Fuel Pump (FP) relay.








^ Connect VAG1 527B voltage tester as follows:
^ Operate starter briefly.
^ LED must light up.
If LED does not light up:
^ Check wire connection from terminal 1 of connector to Fuel Pump (FP) relay via fuse for open circuit:
Refer to Electrical Wiring Diagrams, Troubleshooting & Component Locations
^ Repair open circuit if necessary.
If LED lights up:





Checking activation
^ Connect VAG1 527B voltage tester to connector terminals 1 (B+) and 2
^ Initiate output Diagnostic Test Mode (DTM) and activate Secondary Air Injection (AIR) Solenoid Valve -N112-:
^ LED must blink.
If LED does not blink or if it remains constantly lit:





^ Connect VAG1598/31 test box to harness connectors of wiring harness (do not connect ECM). Connect Ground (GND) clip at test box (not visible in illustration) to Ground (GND).





^ Check the following wire connection for open circuit and short circuit to Ground (GND) and B+:
^ Repair open circuit or short circuit if necessary.