3.
Connect fuel pump relay power terminal (between terminal '30' and terminal '87', junction box side) directly using jump wire.
First of all check damage of harness and terminals : Check terminals for contact resistance, corrosion and deformation.
Measure operating current to inspect connecting condition of power circuit, operating performance of actuator and motor, ground condition.
IG S/W 'OFF', ENGINE 'OFF'
Remove the fuel pump relay.
Connect fuel pump relay power terminal (between terminal '30' and terminal '87', junction box side) directly using jump wire.
IG S/W 'ON' or ENGINE 'ON'.
Measure the current.
IG S/W 'OFF', ENGINE 'OFF'.
Remove the fuel pump relay.
Select the ampere range (A).
Connect red probe to 10A for measuring current.
Connect multimeter probe to terminal '30' and '87'
IG S/W 'ON' or ENGINE 'ON'.
Measure the current.
■ Specification : 5.0 ~ 6.0 A (ENGINE 'ON')
☞ Inspect changes of the waveform ( breaking or decreasing current) and current. Approx 5.0 ~ 6.0 A current is flew in a normal vehicle and the regular waveform like blades is displayed by pulsating motion of fuel pump.
Symptom | Inspection procedure | |
Case1 | ● Current is 0 A intermittently, Engine hesitation occurs or engine stalls. | ● Repair open in fuel pump power supply circuit and poor connection of connectors. ● Repair abnormal chassis ground. |
Case2 | ● Current is increased suddenly and fuel pump fuse is blown. | ● Repair short to ground circuit in fuel pump power supply circuit. |
Case3 | ● Current is too low. | ● Repair the high resistance in fuel pump power supply circuit. ● Repair abnormal chassis ground. ● Repair the high resistance in the fuel pump. |
Case4 | ● There is no trouble while measuring the current. | ● Go to 'Fuel pump relay inspection' |
