Description
| Sensor | Input signal to ECM | ECM Function | Actuator |
| Crankshaft position sensor (POS) Camshaft position sensor (PHASE) |
Engine speed* | Fuel pump control | Fuel pump relay ↓ Fuel pump |
| Battery | Battery 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 (PHASE), 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.
| Condition | Fuel pump operation |
| Ignition switch is turned to ON | Operates for 1 second. |
| Engine running and cranking | Operates. |
| When engine is stopped | Stops in 1.5 seconds. |
| Except as shown above | Stops. |
Component Function Check
1.CHECK FUEL PUMP FUNCTION
Fuel pressure pulsation should be felt on the fuel feed hose for 1 second after ignition switch is turned ON.
Is the inspection result normal? YES >> INSPECTION END
NO >> Proceed to EC-467, "Diagnosis Procedure".
Diagnosis Procedure
1.CHECK FUEL PUMP RELAY CONTROL SIGNAL

Is the inspection result normal? YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK FUEL PUMP RELAY CONTROL SIGNAL CIRCUIT

Also check harness for short to ground and to power.
Is the inspection result normal? YES >> GO TO 7.
NO >> Repair or replace error-detected parts.
3.CHECK FUEL PUMP POWER SUPPLY

Is the inspection result normal? YES >> GO TO 5.
NO >> GO TO 4.
4.CHECK FUEL PUMP POWER SUPPLY CIRCUIT

Is the inspection result normal? YES >> GO TO 7.
NO >> Repair or replace error-detected parts.
5.CHECK FUEL PUMP GROUND CIRCUIT

Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair or replace error-detected parts.
6.CHECK FUEL PUMP
Refer to EC-469, "Component Inspection".
Is the inspection result normal? YES >> GO TO 7.
NO >> Replace “fuel level sensor unit and fuel pump”. Refer to FL-6, "Removal and Installation".
7.CHECK INTERMITTENT INCIDENT
Perform GI-41, "Intermittent Incident".
Is the inspection result normal? YES >> Replace IPDM E/R. Refer to PCS-35, "Removal and Installation".
NO >> Repair or replace harness or connectors.
Component Inspection
1.CHECK FUEL PUMP

Is the inspection result normal? YES >> INSPECTION END
NO >> Replace “fuel level sensor unit and fuel pump”. Refer to FL-6, "Removal and Installation".
Fuel injector
Ignition signalP0444, P0445 EVAP canister purge volume control solenoid
DTC Description
DTC DETECTION LOGIC
DTC No.
CONSULT screen terms
(Trouble diagnosis content)
DTC detecting condition
P0444
PURG VOLUME CONT/V
(Evaporative emission system purge control
valve circuit open)
An excessively low voltage signal is sent to ECM through ...
Sample/Wiring Diagram -Example-
Each section includes wiring diagrams.
Description
Number
Item
Description
1
Power supply
This means the power supply of fusible link or fuse.
2
Fuse
“/” means the fuse.
3
Current rating of fusible
...
Rear window defogger relay
Description
Power is supplied to the rear window defogger with BCM control.
Component Function Check
1. CHECK REAR WINDOW DEFOGGER RELAY POWER SUPPLY CIRCUIT
Check that an operation noise of rear window defogger relay [located in fuse
block (J/B)] can be heard when
turning the rear window def ...