With Generic Scan Tool

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

Recommended special tools and equipment







- VAG1526A hand multimeter
- VAG1594A connector test kit
- VAG1598/31 test box

Test requirements:
- Fuse for Secondary Air Injection (AIR) solenoid valve OK
- Fuel Pump (FP) Relay OK; checking. Testing and Inspection
- Ignition switched off.


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


Work procedure







- Disconnect electrical harness connector from Secondary Air Injection (AIR) Solenoid Valve -N112- (item 2).

Checking internal resistance







- Connect multimeter at valve for resistance measurement.
- Specified value: 27 ... 30 Ohm

If specified value is not obtained.
- Replace Secondary Air Injection (AIR) Solenoid Valve -N112-.

If specified value is obtained:

Checking voltage supply







- Connect multimeter between terminal 1 and 2 for voltage measurement.
- Operate starter briefly.
- Specified value: approx. battery voltage

If there is no voltage:
- Connect multimeter for voltage measurement as follows:

Harness connector Terminal Measure to
1 Engine Ground (GND)

- Operate starter briefly.
- Specified value: approx. battery voltage

- Switch ignition off.

If there is no voltage again:
- Check wire connection from harness connector terminal 1 to Fuel Pump (FP) Relay -J17- via fuse for open circuit according to wiring diagram.
- Specified value: Wire resistance max 1.5 Ohm

- If necessary, repair wire connection.

If voltage supply is OK:

Check Ground (GND) activation







- Connect multimeter for voltage measurement as follows:

Harness connector Terminal Measure to
2 B+

- Operate starter briefly.
- Specified value: approx. battery voltage

- Switch ignition off.

If specified value is not obtained:
- Connect test box to wiring harness of Engine Control Module (ECM); ECM is not connected. Test Box, Connecting For Wiring Test







- Check the following wire connection for open circuit according to wiring diagram:

Harness connector Terminal Test box Socket
2 9

- Specified value: Wire resistance max 1.5 Ohm

- Also check the wire for short circuit to B+ and Ground (GND).
- Specified value: Infinite Ohm (no continuity)

- If necessary, repair wire connection.

If no malfunctions are found in wire:
- Replace Engine Control Module (ECM).

Final procedures
After repair work, the following work steps must be performed in the mentioned sequence:
1 - Check DTC memory "Mode 3: Check DTC memory". Diagnostic Mode 3: Check DTC Memory
2 - If necessary, erase DTC memory "Mode 4: Reset/erase diagnostic data". Diagnostic Mode 4: Reset/Erase Diagnostic Data
3 - Generate readiness code. Readiness Code, Generating
- End diagnosis and switch ignition off.