Fuel Pump and Its Circuit Check: Troubleshooting

NOTE: The connectors of the ECM are watertight. If tester probes are directly connected to any of the connectors when checking the ECM and its circuits, the watertight performance of the connector will be affected, possibly resulting in corrosion of connector terminals and damage to electrical circuits. Always use the special tool when checking the circuits. Connect tester probes only to the special tool's connectors.

DIAGNOSTIC PROCEDURE CHART

Step	Action	YES	NO
1	Fuel pump control system check for operation Remove fuel filler cap. Push engine switch to change ignition mode of keyless push start system to "ON". Confirm that fuel pump operating sound in heard from fuel filler for about 2 seconds and then it stops. Is it in good condition?	Fuel pump circuit is in good condition. Reinstall fuel filler cap.	Go to Step 2.
2	Fuel pump relay power supply check Reinstall fuel filler cap. Confirm that ignition mode of keyless push start system is "OFF". Remove fuel pump relay from main fuse box. Check for proper connection to fuel pump relay at each terminal. If OK, push engine switch to change ignition mode to "ON". Check that voltage between each fuel pump relay power supply circuit (A1, A2) and engine ground is battery voltage, see FUEL PUMP CONTROL SYSTEM CIRCUIT DIAGRAM . Are they in good condition?	Go to Step 3.	Repair fuel pump relay power supply circuit.
3	Fuel pump relay check Check fuel pump relay, see CONTROL RELAY INSPECTION . Is relay in good condition?	Go to Step 4.	Replace fuel pump relay.
4	Fuel pump relay drive circuit check Confirm that ignition mode of keyless push start system is "OFF". Disconnect connectors from ECM. Check for proper terminal connection to ECM connectors. Check the following points, see FUEL PUMP CONTROL SYSTEM CIRCUIT DIAGRAM . Resistance of fuel pump relay drive circuit (B1): less than 3 Ω Resistance between fuel pump relay drive circuit and ground: infinity Voltage of fuel pump relay drive circuit: 0 - 1 V (with the ignition mode of keyless push start system in "ON") Are they in good condition?	Go to Step 5.	Repair fuel pump relay drive circuit.
5	Fuel pump relay drive signal check Confirm that ignition mode of keyless push start system is "OFF". Connect connectors to ECM. Check that voltage between fuel pump relay drive circuit (B1) and ground is 0 - 1 V for 2 sec. after the ignition mode of keyless push start system in "ON", see FUEL PUMP CONTROL SYSTEM CIRCUIT DIAGRAM . Is it in good condition?	Go to Step 6.	Replace ECM and recheck DTC, see ECM REMOVAL AND INSTALLATION .
6	Fuel pump power supply circuit check Confirm that ignition mode of keyless push start system is "OFF". Remove fuel tank. Disconnect connector from fuel pump. Check that resistance between fuel pump power supply circuit (B2) and ground is infinity, see FUEL PUMP CONTROL SYSTEM CIRCUIT DIAGRAM . Is it in good condition?	Go to Step 7.	Repair fuel pump power supply circuit.
7	Fuel pump power supply circuit check Connect service wire between fuel pump circuit (B1) and ground, see FUEL PUMP CONTROL SYSTEM CIRCUIT DIAGRAM . Push engine switch to change ignition mode to "ON". Check that voltage between fuel pump power supply circuit (B2) and ground is battery voltage. Is it in good condition?	Go to Step 8.	Repair fuel pump power supply circuit.
8	Fuel pump ground circuit check Confirm that ignition mode of keyless push start system is "OFF". Check that resistance between fuel pump ground circuit (B3) and ground is less than 3 Ω, see FUEL PUMP CONTROL SYSTEM CIRCUIT DIAGRAM . Is it in good condition?	Replace fuel pump, see FUEL PUMP ASSEMBLY REMOVAL AND INSTALLATION .	Repair fuel pump ground circuit.