Fuel Pump

PUMP CONTROL DESCRIPTION
The ECM activates the fuel pump for several seconds after the ignition switch is turned on to improve engine startability. If the ECM receives a 120 signal from the camshaft position sensor, it knows that the engine is rotating, and causes the pump to operate. If the 120 signal is not received when the ignition switch is on, the engine stalls. The ECM stops pump operation and prevents battery discharging, thereby improving safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump relay, which in turn controls the fuel pump.

Condition / Fuel pump operation
Ignition switch is turned to ON. / Operates for 5 seconds
Engine running and cranking / Operates
When engine is stopped / Stops in 1.5 seconds
Except as shown above / Stops


COMPONENT DESCRIPTION




Fuel pump
The fuel pump with a fuel damper is an in-tank type (the pump and damper are located in the fuel tank).




Inertia fuel shutoff switch
The inertia fuel shutoff switch automatically stops the flow of fuel to the engine when the vehicle is involved in a collision. The impact does not have to be great to trigger the switch. Minor parking lot bumping and severe road impacts (such as potholes) may trigger the switch.
Once the switch is triggered, it must be reset manually before starting the vehicle. Reset the switch by pressing the red button located on the top of the switch.
The inertia fuel shutoff switch is located near the driver's door frame below the hood release handle.




ECM TERMINALS AND REFERENCE VALUE
Specification data are reference values and are measured between each terminal and (43) (ECCS ground).




CONSULT REFERENCE VALUE IN DATA MONITOR MODE

Part 1:

Part 2:

DIAGNOSTIC PROCEDURE

COMPONENT INSPECTION




Fuel pump relay
Check continuity between terminals (3) and (5).

Conditions / Continuity
12V direct current supply between terminals (1) and (2) / Yes
No current supply / No

If NG, replace relay.




Fuel pump
1. Disconnect fuel pump harness connector.
2. Check resistance between terminals (1) and (2).

Resistance: 0.2 - 5.0 Ohms [at 25°C (77°F)]

If NG, replace fuel pump.




Inertia fuel shutoff switch
1. Disconnect inertia fuel shutoff switch harness connector.
2. Check inertia fuel shutoff switch, following the table as shown below:

Conditions / Continuity between terminals (2) and (3)
Switch open (tripped) / No
Switch closed (set) / Yes