Fuel Tank Leak Detection Control Module -J909-, CHECKING

The system can test the evaporative system integrity by applying a vacuum signal, ported or manifold, to the fuel tank in order to create a small vacuum. The Engine Control Module 2 -J624- then monitors the ability of the system to maintain the vacuum through signals sent from the Fuel Tank Pressure Sensor -G400- / 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 2 -J624-. 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 following procedure is used to diagnose the Fuel Tank Leak Detection Control Module -J909-, which is controlled by the Engine Control Module 2 -J624-.

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 .

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: ON. DISCONNECT: Fuel Tank Leak Detection Control Module -J909 - harness connector. CHECK: Fuel Tank Leak Detection Control Module -J909 - harness connector terminal 4 to ground for voltage. SPECIFIED VALUE: Battery voltage. IGNITION: OFF. -- Was value obtained?	YES: GO TO: Step 3. NO: CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals. REPAIR: Faulty wiring or connector. REPLACE: Any open fuses. GO TO: Step 4.
3	REMOVE: Engine Control Module 2 -J624-. Refer to appropriate repair information. CHECK: Fuel Tank Leak Detection Control Module -J909 - harness connector terminal 2 to the Engine Control Module 2 -J624- harness connector terminal T91a / 64 for resistance. CHECK: Fuel Tank Leak Detection Control Module -J909 - harness connector terminal 3 to the Engine Control Module 2 -J624- harness connector terminal T91a / 40 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were values obtained?	YES: REPLACE Engine Control Module 2 -J624-. Refer to appropriate repair information. GO TO: Step 4. NO: 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 4.
4	Final Procedure Perform a road test to verify repair. Do any DTC's return:	YES: Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY . Perform the diagnostic procedure for that DTC. NO: REPAIR is complete. Generate readiness code. Refer to READINESS CODE . Return vehicle to Customer.