ECM Code EO20 - Open Fuel Pump Circuit (Blown Fuse): Notes
NOTE:
Test numbers refer to test numbers on diagnostic chart.
- With key on, light should be off, or light for 2 seconds as relay powers up fuel pump.
- If a short circuit is present, it is in circuit No. 120, in fuel pump, or in ECM. Normal circuit resistance is 3-4 ohms.
- Checks for ECM shorting circuit No. 120A to ground.
- This step checks for short circuit in fuel tank.
- This step checks fuel pump for short circuits, sending unit harness, and RFI suppression connector.
- This step checks circuit No. 120 for a short to ground.
- Check for a grounded fuel pump test point, connection at the relay center, and oil pressure switch. Also check harness for short to ground.
- If light is on steadily, then the non-switched portion of the fuel pump circuit is shorted. Check circuit No. 239.