Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Fuel Tank Leak Detection Control Module, Checking: Notes
Observe all safety precautions: SAFETY PRECAUTIONS .
View clean working conditions: CLEAN WORKING CONDITIONS .
Use only gold-plated terminals when servicing any component with gold-plated electrical harness connector terminals:
For wiring diagrams, component locations, and connector views, Refer to the appropriate System Wiring Diagram.
The following procedure is used to diagnose the Fuel Tank Lead Detection Control Module -J909- which is controlled by Engine Control Module -J623-.
Special tools and workshop equipment required
- Multimeter.
- Wiring diagram.
Test requirements
- The Engine Component Power Supply Relay -J757- OK.
- The Fuse -SF2- OK.
- The fuel filter OK.
- The parking brake engaged.
- The battery voltage at least 12.5 V.
- The selector lever of automatic transmission in position "P" or "N".
- All electrical consumers switched OFF.
- A/C switched OFF.
- The fuel tank at least 1 /4 filled.
- The ignition switched OFF.
Test procedure
-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK .
Start diagnosis
-- Remove the left rear underbody protective cover.
-- Using a Multimeter, Check the Fuel Tank Lead Detection Control Module -J909- electrical harness connector terminals 1 to 3 for voltage.
-- Switch the ignition ON.
Specified value: Battery voltage.
-- Switch the ignition OFF.
-- Continue test according to the following table:
| Value | Cause | Test |
|---|---|---|
| If the specified value was not obtained: | Open or shorted circuit | FUEL TANK LEAK DETECTION CONTROL MODULE, CHECKING => Checking wiring |
| If the specified value was obtained: | Check reference signal circuit | FUEL TANK LEAK DETECTION CONTROL MODULE, CHECKING => Checking wiring |
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.