Activating secondary air injection (AIR) solenoid valve N112 :

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Press → key.

Indicated on display:

Output Diagnostic Test Mode →
Secondary air injection solenoid valve -N112-

The secondary air inlet valve must run until the next control element is activated by pressing the → key.

If the valve does not click:

Fig 1: Secondary AIR Solenoid Valve, Bracket & Connector

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Remove retainer - 3 -.
Pull connector - 1 - off solenoid valve - 2 - and connect voltage tester VAG1527B with adapter cables from VAG1594 to disconnected connector.

LED must flash

LED flashes:

Proceed with Output Diagnostic Test Mode until completed.
Switch ignition off.

Fig 2: Secondary AIR Solenoid Valve, Bracket & Connector

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Replace secondary air injection solenoid valve - 2 - : → 26 - EXHAUST SYSTEM, EMISSION CONTROLS
Check DTC Memory, if necessary, repair any malfunctions and then Erase DTC Memory → DTC memory (functions 02 and 05), checking and erasing
Read readiness code → Readiness code, reading . If DTC memory has been erased, readiness code must be generated again:

Engine code AWW, → Readiness code for engine code AWW, generating

Engine code AWP, → Readiness code for engine code AWP, generating

LED does not flash:

Proceed with Output Diagnostic Test Mode until completed.
Switch ignition off.

Fig 3: Identifying Test Box V.A.G 1598/31 Connected To Control Module Wiring Harness

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Connect test box VAG1598/31 to control module wiring harness. Engine control module remains disconnected.
Check wire for open circuit between test box socket 9 and 2-pin connector contact 2 using wiring diagram.

Wire resistance: max. 1.5 Ω

Additionally check wire for short to battery positive and Ground (GND).

If no wiring malfunction is detected:

Check wire between 2 pin connector contact 1 and fuel pump (FP) relay J17 for open circuit using wiring diagram.

Wire resistance: max. 1.5 Ω

If no wiring fault is detected:

Replace engine control module → Engine control module, replacing .