Secondary Air Injection Solenoid Valve -N112-, Checking

WARNING: This page does not describe the selected car, but rather 12 other vehicles, including the 2017 Audi S5, 2016 Audi S5, 2016 Audi S4, 2015 Audi S5, and 2015 Audi S4. However, it is still accessible from the selected car via links, so may be relevant.

General Description

The secondary air injection system blows air into the exhaust on a cold-start of the engine for 45 - 100 seconds and serves to quickly heat the catalytic converter(s) for improved emissions. An O2 sensor based diagnostics function is used. In this system, the O2 sensor signal is evaluated in the Engine Control Module -J623-.

Special tools and workshop equipment required

Multimeter.
Wiring Diagram.
Scan Tool.

Test requirements

Fuses OK.
Battery voltage OK.
Switch OFF All electrical and electronic accessories.
Vehicles with Auto. Transmission, ensure Selector Lever position is in "P".
Vehicles with Manual Transmission, ensure Shifter Lever position is in "N" with Parking Brake applied.
Coolant Temperature: ≥ 80° C.
Observe all safety precautions: SAFETY PRECAUTIONS .
View clean working conditions: CLEAN WORKING CONDITIONS .
For Hybrid vehicles refer to: HIGH VOLTAGE SYSTEM GENERAL WARNINGS .

Test Procedure

Step	Procedure	Result / Action to Take
1	PERFORM: Preliminary Check to verify the customers complaint. Refer to PRELIMINARY CHECK . -- Was Complaint verified?	-- YES: GO TO: Step 2 -- NO: GATHER more information from customer about the complaint.
2	IGNITION: OFF. DISCONNECT: Secondary Air Injection Solenoid Valve -N112- harness connector. CHECK: Secondary Air Injection Solenoid Valve -N112- component connector terminals 1 to 2 for resistance. SPECIFIED VALUE: 20 to 35 Ω (at approx. 20° C). -- Was Value obtained?	-- YES: GO TO: Step 3 -- NO: REPLACE: Secondary Air Injection Solenoid Valve -N112-. Refer to appropriate repair information. GO TO: Step 5
3	IGNITION: ON. CHECK: Secondary Air Injection Solenoid Valve -N112- harness connector terminal 1 to ground for voltage. SPECIFIED VALUE: Battery voltage. IGNITION: OFF. -- Was Value obtained?	-- YES: GO TO: Step 4 -- NO: PERFORM: Visual Inspection of wiring and component. CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals. REPAIR: Faulty wiring or connector. GO TO: Step 5
4	REMOVE: Engine Control Module - J623-. Refer to appropriate repair information. CHECK: Secondary Air Injection Solenoid Valve -N112- harness connector terminal 2 to the Engine Control Module - J623- harness connector T94 / 49 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: GO TO: Step 5 -- NO: PERFORM: Visual Inspection of wiring and component. CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals. REPAIR: Faulty wiring or connector. GO TO: Step 5
5	Final Procedure Perform a road test to verify repair. -- Does the original DTC return?	-- YES: CHECK: Engine Control Module -J623- harness connector for any damaged, pushed-out pins. REPAIR: As necessary. Clear the DTC's. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY . Repair is complete. Generate Readiness Code. Refer to READINESS CODE . Return vehicle to Customer. If all electrical connections are OK: REPLACE: Engine Control Module -J623-. Refer to appropriate repair information. Repair is complete. Generate Readiness Code. Refer to READINESS CODE . Return vehicle to Customer. -- NO: Perform the diagnostic procedure for any DTC's. If no DTC's return the repair is complete. Return vehicle to customer.