Nissan Versa (N17): P0643 sensor power supply

DTC Logic

DTC DETECTION LOGIC

DTC No.	Trouble diagnosis name	DTC detecting condition	Possible cause
P0643	Sensor power supply circuit short	ECM detects a voltage of power source for sensor is excessively low or high.	Harness or connectors (Accelerator pedal position 1 circuit is shorted.) (Throttle position sensor 1 circuit is shorted.) (Intake camshaft position sensor circuit is shorted.) (Exhaust camshaft position sensor circuit is shorted.) (Engine oil pressure sensor circuit is shorted.) Accelerator pedal position sensor Throttle position sensor Intake camshaft position sensor Exhaust camshaft position sensor Engine oil pressure sensor

DTC CONFIRMATION PROCEDURE

1.PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.

1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION: Before performing the following procedure, confirm that battery voltage is more than 10 V at idle.

>> GO TO 2.

2.PERFORM DTC CONFIRMATION PROCEDURE

1. Start engine and let it idle for 1 second.
2. Check DTC.

Is DTC detected?

YES >> Go to EC, "Diagnosis Procedure".

NO >> INSPECTION END

Diagnosis Procedure

1.CHECK GROUND CONNECTION

1. Turn ignition switch OFF.
2. Check ground connection E15. Refer to Ground Inspection in GI, "Circuit Inspection".

Is the inspection result normal?

YES >> GO TO 2.

NO >> Repair or replace ground connection.

2.CHECK SENSOR POWER SUPPLY

1. Turn ignition switch ON.
2. Check the voltage between ECM harness connector and ground.

Is the inspection result normal?

YES >> GO TO 5.

NO >> GO TO 3.

3.CHECK SENSOR POWER SUPPLY CIRCUIT

1. Turn ignition switch OFF.
2. Check harness for short to power and short to ground, between the following terminals.

Is the inspection result normal?

YES >> GO TO 4.

NO >> Repair short to ground or short to power in harness or connectors.

4.CHECK COMPONENTS

Check the following.

• Throttle position sensor 1 (Refer to EC, "Component Inspection".)
• Engine oil pressure sensor (Refer to EC, "Component Inspection".)
• Intake camshaft position sensor (Refer to EC, "Component Inspection".)
• Exhaust camshaft position sensor (Refer to EC, "Component Inspection".)
• Accelerator pedal position sensor 1 (Refer to EC, "Component Inspection".)

Is the inspection result normal?

YES >> GO TO 5.

NO >> Replace malfunctioning component.

5.CHECK INTERMITTENT INCIDENT

Refer to GI, "Intermittent Incident".

>> INSPECTION END