Secondary Air Injection Solenoid Valve - N112-, Checking

General Description

The secondary air injection system injects air into the exhaust on a cold-start of the engine for about 45 - 100 s. and serves to quickly heat the catalytic converter(s) for improved emissions. A "pressure based secondary air diagnostics" function is used. In this system, the Engine/Motor Control Module -J623- controls the Secondary Air Injection Solenoid Valve -N112-, which allows the air quantity necessary to be injected into the exhaust.

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 automatic transmission, ensure the selector lever position is in "P".
Vehicles with manual transmission, ensure the shifter lever position is in "N" with the parking brake applied.
Observe all safety precautions: SAFETY PRECAUTIONS .
View clean working conditions: CLEAN WORKING CONDITIONS .

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 Secondary Air Injection Solenoid Valve - N112-, CHECKING => 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: 5 - 35 Ω (@ approx. 20° C). -- Was Value obtained?	-- YES: GO TO: Step 3 Secondary Air Injection Solenoid Valve - N112-, CHECKING => 3 . -- NO: REPLACE: Secondary Air Injection Solenoid Valve -N112-. Refer to appropriate Service Information. GO TO: Step 5 Secondary Air Injection Solenoid Valve - N112-, CHECKING => 5 .
3	IGNITION: ON. CHECK: Secondary Air Injection Solenoid Valve -N112- harness connector terminal 2 to ground for voltage. SPECIFIED VALUE: Battery voltage. IGNITION: OFF. -- Was Value obtained?	-- YES: GO TO: Step 4 Secondary Air Injection Solenoid Valve - N112-, CHECKING => 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 Secondary Air Injection Solenoid Valve - N112-, CHECKING => 5 .
4	REMOVE: Engine/Motor Control Module - J623-. Refer to appropriate Service Information. CHECK: Secondary Air Injection Solenoid Valve -N112- harness connector terminal 1 to the Engine/Motor Control Module - J623- harness connector T105 / 67 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Was Value obtained?	-- YES: TIP: The Secondary Air Injection Solenoid Valve -N112- may fail under loaded operation; please swap a known good Secondary Air Injection Solenoid Valve -N112- prior to continuing to the next step. GO TO: Step 5 Secondary Air Injection Solenoid Valve - N112-, CHECKING => 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 Secondary Air Injection Solenoid Valve - N112-, CHECKING => 5 .
5	Final Procedure Perform a road test to verify repair. -- Does the original DTC return?	-- YES: CHECK: Engine/Motor Control Module -J623- harness connector for any damaged, pushed-out pins. REPAIR: As necessary. If all electrical connections are OK: REPLACE: Engine/Motor Control Module -J623-. Refer to appropriate Service Information. 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. -- NO: Perform the diagnostic procedure for any DTC's. If no DTC's return, the repair is complete. Return vehicle to customer.