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DTC Diagnosis Procedure
SensorInput signal to ECMECM FunctionActuator
Crankshaft position sensor
Camshaft position sensor
Engine speed*Fuel pump controlFuel pump relay
↓
Fuel pump
BatteryBattery voltage*
*: ECM determines the start signal status by the signals of engine speed and battery voltage.
The ECM activates the fuel pump for several seconds after the ignition switch is turned ON to improve engine start ability. If the ECM receives a engine speed signal from the camshaft position sensor, it knows that the engine is rotating, and causes the pump to operate. If the engine speed 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.
ConditionFuel pump operation
Ignition switch is turned to ON.Operates for 1 second.
Engine running and crankingOperates.
When engine is stoppedStops in 1.5 seconds.
Except as shown aboveStops.
1.CHECK FUEL PUMP RELAY CONTROL SIGNAL
  1. Turn ignition switch ON.
  2. Check the voltage between ECM harness connector.
    ECMVoltage
    +-
    ConnectorTerminalConnectorTerminal
    F5129E16156Battery voltage should exist 1 second after ignition switch is turn ON.
Is the inspection result normal?
.
 
2.CHECK FUEL PUMP RELAY CONTROL SIGNAL CIRCUIT
  1. Turn ignition switch OFF.
  2. Disconnect ECM harness connector.
  3. Disconnect IPDM E/R harness connector.
  4. Check the continuity between ECM harness connector and IPDM E/R harness connector.
    +-Continuity
    ECMIPDM E/R
    ConnectorTerminalConnectorTerminal
    F5129F3576Existed
  5. Also check harness for short to ground and to power.
Is the inspection result normal?
.
Repair or replace error-detected parts.
 
3.CHECK FUEL PUMP POWER SUPPLY
  1. Turn ignition switch OFF.
  2. Disconnect “fuel level sensor unit and fuel pump” harness connector.
  3. Turn ignition switch ON.
  4. Check the voltage between “fuel level sensor unit and fuel pump” harness connector and ground.
    +-Voltage
    Fuel level sensor unit and fuel pump
    ConnectorTerminal
    B10 1GroundBattery voltage should exist 1 second after ignition switch is turn ON.
Is the inspection result normal?
.
.
 
4.CHECK FUEL PUMP POWER SUPPLY CIRCUIT
  1. Turn ignition switch OFF.
  2. Disconnect IPDM E/R harness connector.
  3. Check the continuity between IPDM E/R harness connector and “fuel level sensor unit and fuel pump” harness connector.
    +-Continuity
    IPDM E/RFuel level sensor unit and fuel pump
    ConnectorTerminalConnectorTerminal
    E12146B10 1Existed
  4. Also check harness for short to ground and to power.
Is the inspection result normal?
.
Repair or replace error-detected parts.
 
5.CHECK FUEL PUMP GROUND CIRCUIT
  1. Check the continuity between “fuel level sensor unit and fuel pump” and ground.
    +-Continuity
    Fuel level sensor unit and fuel pump
    ConnectorTerminal
    B10 4GroundExisted
  2. Also heck harness for short to power.
Is the inspection result normal?
.
Repair or replace error-detected parts.
 
6.CHECK FUEL PUMP
Refer to Component Inspection.
Is the inspection result normal?
.
Replace “fuel level sensor unit and fuel pump”. Refer to Exploded ViewRemoval and Installation.
 
7.CHECK INTERMITTENT INCIDENT
Refer to Intermittent IncidentIntermittent Incident.
Is the inspection result normal?
Replace IPDM E/R. Refer to Removal and Installation.
Repair or replace harness or connectors.