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.
Diagnosis Procedure
- CHECK GROUND CONNECTIONS
- Turn ignition switch OFF.
- Loosen and retighten ground screws on the body.
Refer to "GROUND INSPECTION ".
OK or NG
OK: GO TO 2.
NG: Repair or replace ground connections.
- CHECK FPCM POWER SUPPLY CIRCUIT
- Disconnect fuel pump control module (FPCM) harness connector.
- Turn ignition switch ON.
- Check voltage between FPCM terminal 2 and ground with CONSULT-III or tester.
Voltage: Battery voltage
OK or NG
OK: GO TO 4.
NG: GO TO 3.
- DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E106, B4
- Harness for open or short between FPCM and harness connector B4
Repair open circuit or short to ground or short to power in harness or connectors.
- CHECK FPCM GROUND CIRCUIT FOR OPEN AND SHORT-I
- Turn ignition switch OFF.
- Check harness continuity between FPCM terminal 3 and ground.
Refer to SYSTEM WIRING DIAGRAMS article.
Continuity should exist .
- Also check harness for short to power.
OK or NG
OK: GO TO 5.
NG: Repair open circuit or short to power in harness or connectors.
- CHECK FPCM GROUND CIRCUIT FOR OPEN AND SHORT-II
- Disconnect "fuel level sensor unit and fuel pump" harness connector (1).
- Illustration shows the view with rear seat cushion and inspection hole cover (RH) removed.
- Vehicle Front
- Disconnect dropping resistor harness connector.
- Check harness continuity between the following;
"fuel level sensor unit and fuel pump" terminal 3 and dropping resistor terminal 2,
FPCM terminal 4 and dropping resister terminal 2.
Refer to SYSTEM WIRING DIAGRAMS article.
Continuity should exist .
- Check harness continuity between the following;
"fuel level sensor and fuel pump" terminal 3 and ground,
FPCM terminal 4 and ground.
Refer to SYSTEM WIRING DIAGRAMS article.
Continuity should not exist .
- Also check harness for short to power.
OK or NG
OK: GO TO 7.
NG: GO TO 6.
- Disconnect "fuel level sensor unit and fuel pump" harness connector (1).
- DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors B434, B65
- Harness for open or short between "fuel level sensor unit and fuel pump" and dropping resistor
- Harness for open or short between FPCM and dropping resistor
- Harness for open or short between "fuel level sensor unit and fuel pump" and ground
- Harness for open or short between FPCM and ground
Repair open circuit or short to ground or short to power in harness or connectors.
- CHECK FPCM INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
- Disconnect ECM harness connector.
- Check harness continuity between ECM terminal 38 and FPCM terminal 4.
Refer to SYSTEM WIRING DIAGRAMS article.
Continuity should exist .
- Check harness continuity between ECM terminal 38 and ground.
Refer to SYSTEM WIRING DIAGRAMS article.
Continuity should not exist .
- Also check harness for short to power.
OK or NG
OK: GO TO 9.
NG: GO TO 8.
- DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors B2, M13
- Harness connectors M72, F102
- Harness for open or short between ECM and FPCM
Repair open circuit or short to ground or short to power in harness or connectors.
- CHECK FPCM OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
- Check harness continuity between ECM terminal 39 and FPCM terminal 1.
Refer to SYSTEM WIRING DIAGRAMS article.
Continuity should exist .
- Also check harness for short to ground and short to power.
OK or NG
OK: GO TO 11.
NG: GO TO 10.
- Check harness continuity between ECM terminal 39 and FPCM terminal 1.
- DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors B2, M13
- Harness connectors M72, F102
- Harness for open or short between ECM and FPCM
Repair open circuit or short to ground or short to power in harness or connectors.
- CHECK FPCM
Refer to "COMPONENT INSPECTION ".
OK or NG
OK: GO TO 12.
NG: Replace FPCM.
- CHECK INTERMITTENT INCIDENT
Refer to "DIAGNOSIS PROCEDURE ".
INSPECTION END
Use the Manual With the Right Hardware
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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.
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