Fuel Tank Leak Detection Control Module - J909-, CHECKING

General Description

The system tests the evaporative system integrity by applying a vacuum signal using the Leak Detection Pump -V144-, which is part of the Fuel Tank Leak Detection Control Module -J909-, to the fuel tank in order to create a small vacuum. The Engine Control Module -J623- then monitors the ability of the system to maintain the vacuum through signals sent from the sensor in the Fuel Tank Leak Detection Control Module -J909-. If the vacuum remains for a specified period of time, then there are no evaporative leaks, and a PASS is reported by the Engine Control Module -J623-. If there is a leak, the system either will not achieve a vacuum, or a vacuum cannot be maintained. Usually a fault can only be detected after a cold start.

The Fuel Tank Leak Detection Control Module -J909- contains the following component:

Leak Detection Pump -V144-

The Fuel Tank Leak Detection Control Module -J909- 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 concern. Refer to PRELIMINARY CHECK . -- Was Complaint verified?	-- YES: GO TO: Step 2 Fuel Tank Leak Detection Control Module - J909-, CHECKING - 2 . -- NO: GATHER more information from customer about the complaint.
2	IGNITION: OFF. REMOVE: Evaporative Canister. Refer to appropriate repair information. Plug or Cap off the Fuel Tank Leak Detection Control Module -J909- port going to the vent filter. CONNECT: Hand vacuum pump to the Fuel Tank Leak Detection Control Module -J909- CAN port and apply 0.700 bar and see if the vacuum holds. -- Did the vacuum hold?	-- YES: GO TO: Step 3 Fuel Tank Leak Detection Control Module - J909-, CHECKING - 3 . -- NO: REPLACE: Fuel Tank Leak Detection Control Module -J909-. Refer to appropriate repair information. GO TO: Step 5 Fuel Tank Leak Detection Control Module - J909-, CHECKING - 5 .
3	DISCONNECT: Fuel Tank Leak Detection Control Module -J909- harness connector. IGNITION: ON. CHECK: Fuel Tank Leak Detection Control Module -J909- harness connector terminal 4 to ground for voltage. IGNITION: OFF. SPECIFIED VALUE: Battery voltage. -- Was Value obtained?	-- YES: GO TO: Step 4 Fuel Tank Leak Detection Control Module - J909-, 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 Fuel Tank Leak Detection Control Module - J909-, CHECKING - 5 .
4	REMOVE: Engine Control Module - J623-. Refer to appropriate repair information. CHECK: Fuel Tank Leak Detection Control Module -J909- harness connector terminal 1 to the Engine Control Module - J623- harness connector T91a / 74 for resistance. CHECK: Fuel Tank Leak Detection Control Module -J909- harness connector terminal 2 to the Engine Control Module - J623- harness connector T91a / 39 for resistance. CHECK: Fuel Tank Leak Detection Control Module -J909- harness connector terminal 3 to the Engine Control Module - J623- harness connector T91a / 40 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: REPLACE: Fuel Tank Leak Detection Control Module -J909-. Refer to appropriate repair information. GO TO: Step 5 Fuel Tank Leak Detection Control Module - J909-, 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 Fuel Tank Leak Detection Control Module - J909-, CHECKING - 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 repair 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.