EGR Valve 1 -GX5-, Checking

General Description

The EGR Vacuum Regulator Solenoid Valve -N18- is a positioning motor used to actuate the exhaust gas recirculation valve. The exhaust gas recirculation rate is determined by means of a performance map in the Engine Control Module -J623-. The EGR Vacuum Regulator Solenoid Valve -N18- receives a pulse-width modulated signal from the Engine Control Module -J623- to control the flow of exhaust gas into the intake manifold. The EGR Potentiometer -G212- monitors the position of the EGR Valve 1 -GX5- and reports the EGR Valve 1 -GX5- position to the Engine Control Module -J623-.

The EGR Valve 1 -GX5- contains the following components:

EGR Vacuum Regulator Solenoid Valve -N18-.
EGR Potentiometer -G212-.

The EGR Valve 1 -GX5- components cannot be serviced separately, and they must be serviced as a unit.

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. -- NO: GATHER more information from customer about the complaint.
2	IGNITION: OFF. DISCONNECT: EGR Valve 1 -GX5- harness connector. IGNITION: ON. CHECK: EGR Valve 1 -GX5- harness connector terminals 1 to 3 for voltage. SPECIFIED VALUE: About 5.0 V. IGNITION: OFF. -- Was Value obtained?	-- YES: GO TO: Step 3. -- NO: GO TO: Step 4.
3	REMOVE: Engine Control Module - J623-. Refer to appropriate Service Information. CHECK: EGR Valve 1 -GX5- harness connector terminals 2 to the Engine Control Module - J623- harness connector terminals T105 / 44 for resistance. CHECK: EGR Valve 1 -GX5- harness connector terminals 5 to the Engine Control Module - J623- harness connector terminals T105 / 99 for resistance. CHECK: EGR Valve 1 -GX5- harness connector terminals 6 to the Engine Control Module - J623- harness connector terminals T105 / 43 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: REPLACE: EGR Valve 1 -GX5-. Refer to appropriate Service Information. 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.
4	REMOVE: Engine Control Module - J623-. Refer to appropriate Service Information. CHECK: EGR Valve 1 -GX5- harness connector terminal 1 to the Engine Control Module - J623- harness connector T105 / 57 for resistance. CHECK: EGR Valve 1 -GX5- harness connector terminal 3 to the Engine Control Module - J623- harness connector T105 / 58 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. If all electrical connections are OK: REPLACE: Engine 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.