Nissan Versa

 Sedan Service Manual

Engine » Engine control system (EC) » P0643 sensor power supply
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

DTC Logic

Diagnosis Procedure