Fuel Pump and Its Circuit Check: Troubleshooting
NOTE:
- Before performed troubleshooting, be sure to read the PRECAUTIONS OF ECM CIRCUIT INSPECTION .
- When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the special tool to ECM and/or the ECM connectors referring to INSPECTION OF ECM AND ITS CIRCUITS .
TROUBLESHOOTING PROCEDURES
| Step | Action | YES | NO |
|---|---|---|---|
| 1 | Fuel pump control system check for operation Is fuel pump heard to operate 2 sec. after ignition switch is turned ON? |
Fuel pump circuit is in good condition. | Go to Step 2. |
| 2 | Fuel pump relay power supply check
|
Go to Step 3. | "BLK/WHT" wire is open or shorted to ground circuit. |
| 3 | Fuel pump relay power supply check
|
Go to Step 4. | "BLK/RED" wire is open circuit. |
| 4 | Fuel pump relay check
|
Go to Step 5. | Faulty relay. |
| 5 | Fuel pump relay drive signal check
|
Go to Step 6. | "GRN/WHT" wire is open circuit or shorted to ground circuit. |
| 6 | Fuel pump relay drive signal check
|
Go to Step 7. | Substitute a known-good ECM and recheck. |
| 7 | Wire circuit check
Is resistance infinity? |
Go to Step 8. | "PNK" wire is shorted to ground. |
| 8 | Fuel pump circuit check
|
Go to Step 9. | "PNK" wire is open circuit. |
| 9 | Fuel pump circuit check
|
Faulty fuel pump. | "BLK" wire is open circuit. |